Synthesis of cyclic peptides

Abstract

Methods for performing peptide synthesis, in particular for cyclic peptide synthesis, are generally described. Reaction intermediates of the peptide synthesis are also described.

Description

Technical Field

[0001] The present invention relates to a method and intermediates for preparing a monocyclic peptide, which can be used as an inhibitor of interleukin-23 receptor (IL-23R).

[0002] Incorporation of Sequence Listing

[0003] A sequence listing in ST.26 XML format, named P086982WO_ST26_sequence_listing.xml, created on November 20, 2023, comprises 14,938 bytes, is prepared in accordance with 37 CFR 1.822 to 1.824, and is filed concurrently with the filing of this application, the entire text of which is incorporated herein by reference. Background Art

[0004] Interleukin-23 (IL-23) cytokines have been implicated as playing a key role in the pathogenesis of autoimmune inflammation and related diseases and conditions such as multiple sclerosis, asthma, rheumatoid arthritis, psoriasis, and inflammatory bowel disease (IBD), such as ulcerative colitis and Crohn's disease. Peptide inhibitors that bind to IL-23R and inhibit the binding of IL-23 to IL-23R have been identified (see, for example, U.S. Patent Application Publication No. US2013 / 0029907). Efficient synthesis of these peptides is a contemporary challenge. In solid-phase peptide synthesis, amino acids or peptides are typically bound to a solid support via the C-terminus. New amino acids are added to the bound amino acids or peptides via a coupling reaction. Although solid-phase peptide synthesis technology has been widely used, its process is laborious and the reaction product needs to be purified by chromatography after each step, resulting in high costs, slow processes, and increased difficulty. Therefore, there is a need for improved methods and systems for more efficient peptide synthesis. Summary of the Invention

[0005] The present invention particularly provides methods and intermediates for preparing monocyclic peptides or salts thereof. Specifically, the present invention provides a method for preparing a monocyclic compound, comprising coupling a monocyclic peptide fragment with a linear peptide fragment, wherein the monocyclic peptide fragment is a peptide containing 4 to 11 amino acid residues; wherein the monocyclic peptide fragment comprises a ring containing 4 to 8 amino acid residues; wherein the linear peptide fragment is a peptide containing 4 to 10 amino acid residues; and wherein an amide bond is formed between the monocyclic peptide fragment and the linear peptide fragment. The present invention is suitable for the synthesis of IL-23 receptor peptide inhibitors.

[0006] The present invention also provides a monocyclic peptide fragment, which is a compound of formula (III):

[0007] R 1 -X3a-X4a-X5a-X6a-X7a-X8a-X9a-X10a-R3

[0008] (III)

[0009] in

[0010] R 1 H or C 1-20 Alkanoyl;

[0011] R 3 OH or OP 2 ;

[0012] P 2 is a carboxyl protecting group;

[0013] X3a does not exist or is any amino acid residue;

[0014] X4a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide);

[0015] X5a is Cit, Glu, Gly, substituted Gly, Leu, Ile, β-Ala, Ala, Lys, Asn, Pro, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, Lys(Ac), α-MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), Gln, Asp or Cys;

[0016] X6a is Thr, 2-aminoisobutyric acid, Asp, Dab, Gly, Pro, Ser, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, α-MeThr, α-MeSer, or Val;

[0017] X7a is unsubstituted Trp, or Trp substituted with cyano, halo, alkyl, substituted or unsubstituted aryl, haloalkyl, hydroxyl or alkoxy;

[0018] X8a is Gln, α-Me-Lys, α-MeLeu, α-MeLys(Ac), β-homoGln, Cit, Glu, Phe, Asn, Thr, Val, 2-aminoisobutyric acid, α-MeGln, α-MeAsn, Lys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), 1Nal, 2Nal or Trp;

[0019] X9a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide);

[0020] X10a is unsubstituted Phe, or Phe substituted with halo, alkyl, haloalkyl, hydroxyl, alkoxy, carboxyl, carboxamido, 2-aminoethoxy, or 2-acetylaminoethoxy; and the compound is cyclized via a Pen-Pen disulfide bond between X4a and X9a; or the compound is cyclized via an Abu-Cys or Abu-Pen thioether bond between X4a and X9a. The present invention also provides a linear peptide fragment, which is a compound of formula (IV):

[0021] R 2 -X11a-X12a-X13a-X14a-X15a-X16a-R 4

[0022] (IV)

[0023] in

[0024] R 2 is H;

[0025] R 4 For NHP 1 or NH2;

[0026] P 1 is an amino protecting group;

[0027] X11a is 2Nal, unsubstituted Trp, or Trp substituted with cyano, halo, alkyl, haloalkyl, hydroxy, alkoxy, Phe(2-Me), Phe(3-Me), Phe(4-Me), Phe(3,4-dimethoxy), or 1Nal;

[0028] X12a is 4-amino-4-carboxytetrahydropyran (Gly(THP)), α-MeLys, α-MeLeu, α-MeArg, α-MePhe, α-MeLeu, α-MeLys, α-MeAsn, α-MeTyr, Ala or cyclohexylAla, Lys or 2-aminoisobutyric acid;

[0029] X13a is 2-aminoisobutyric acid, Glu, Cit, Gln, Lys(Ac), α-MeArg, α-MeGlu, α-MeLeu, α-MeLys, α-Me-Asn, α-MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), or Lys; or X13a is Lys, pegylated Lys, b-homoGlu, or Lys(Y2-Ac), wherein Y2 is an amino acid residue;

[0030] X14a is Asn, 2Nal, 2-aminoisobutyric acid, Arg, Cit, Asp, Phe, Gly, Lys, Leu, Ala, (D)Ala, β-Ala, His, Thr, n-Leu, Gln , Ser, (D)Ser, Tic, Trp, α-MeGln, α-MeAsn, α-MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac) or Lys(Ac);

[0031] X15a is Ala, β-Ala, Arg, Asn, Asp, Cit, Cys, Glu, Gln, Gly, substituted or unsubstituted His, (D)His, Ile, Lue, (D)Lue, Lys, (D)Lys, Met, 2Pal, 3Pal or 4Pal, Phe, Pro, 5-Pyal, 2Quin, 3Quin, Ser, Thr, Trp, Tyr, Val; Leu; and

[0032] X16a is absent or is Sarc, aMeLeu, (D)NMeTyr, His, (D)Thr, bAla, Pro, or (D)Pro.

[0033] The present invention also provides a compound of formula (VI):

[0034] R 2 -X7a-X8a-X9a-X10a-R 5

[0035] (VI)

[0036] where R 2 is H;

[0037] R 5 NH2 or NHP 1 ;

[0038] P 1 is an amino protecting group;

[0039] X7a is unsubstituted Trp, or Trp substituted with cyano, halo, alkyl, substituted or unsubstituted aryl, haloalkyl, hydroxyl or alkoxy;

[0040] X8a is Gln, α-Me-Lys, α-MeLeu, α-MeLys(Ac), β-homoGln, Cit, Glu, Phe, Asn, Thr, Val, 2-aminoisobutyric acid, α-MeGln, α-MeAsn, Lys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), 1-Nal, 2Nal or Trp;

[0041] X9a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide); and

[0042] X10a is unsubstituted Phe, or Phe substituted with halo, alkyl, haloalkyl, hydroxy, alkoxy, carboxyl, carboxamido, 2-aminoethoxy, or 2-acetylaminoethoxy.

[0043] The present invention also provides a compound of formula (V):

[0044] R 1 -X3a-X4a-X5a-X6a-R 3

[0045] (V)

[0046] where R 1 H or C 1-20 Alkanoyl;

[0047] R 3 OH or OP 2 ;

[0048] P 2 is a carboxyl protecting group;

[0049] X3a does not exist or is any amino acid residue;

[0050] X4a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide);

[0051] and

[0052] X6a is Thr, 2-aminoisobutyric acid, Asp, Dab, Gly, Pro, Ser, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, α-MeThr, α-MeSer or Val. DETAILED DESCRIPTION

[0053] The present invention provides a method for preparing a monocyclic peptide or a salt thereof via convergent solution-phase synthesis, in which a monocyclic peptide fragment is coupled to a linear peptide fragment. This method avoids the need for a solid support. Also disclosed are method steps for preparing the monocyclic peptide fragment and the linear peptide fragment using a convergent method, which can be performed in solution phase. Also provided are intermediates for preparing the monocyclic peptide, the monocyclic peptide fragment, and the linear peptide fragment.

[0054] By forming amide bonds between the peptide fragments, the single-ring peptide fragments are coupled together to form larger fragments. The coupling of the peptide fragments is carried out using any suitable amide coupling reagent, for example, an amide coupling reagent described in the following literature: "Peptide Coupling Reagents, more a Lett Soup", A. El-Faham, F. Albericio; Chem. Rev., 2011, Vol. 111, pp. 6657-6602. Non-limiting examples of coupling reagents include carbodiimide coupling reagents, carbodiimide coupling reagents with additives (activated esters), ammonium-based coupling reagents, urea-based reagents, phosphonium-based coupling reagents, halogenated reagents, and mixed anhydride reagents. Also used to prepare amide bonds are acylazoles, acyl azides, acid halides, organophosphorus reagents, organosulfur reagents, triazine coupling reagents, and pyridinium coupling reagents, such as those described in the following literature: "Peptide Coupling Reagents, more than a Letter Soup", A. El-Faham, F. Albericio; Chem. Rev., 2011, Vol. 111, pp. 6657-6602.

[0055] Amide bonds can be formed using coupling reagents selected from the group consisting of carbodiimide coupling reagents, carbodiimides in the presence of additives, ammonium coupling reagents, urea coupling reagents, phosphonium coupling reagents, halogenating reagents (e.g., chlorinating reagents), acylazoles, acyl azides, acid halides, organophosphorus reagents, organosulfur reagents, triazine coupling reagents, pyridinium coupling reagents, mixed anhydride reagents, activated esters, and enzymatic biocatalytic systems. Carbodiimide coupling reagents include N,N'-diisopropylcarbodiimide (DIC), N,N'-dicyclohexylcarbodiimide (DCC), 1,1'-carbonyldiimidazole (CDI), N-ethyl-N'-dimethylaminopropylcarbodiimide (EDC), N-ethyl-N'(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCI), N-cyclohexyl-N'-isopropylcarbodiimide (CIC), N-tert-butyl-N'-methylcarbodiimide (BMC), N-tert-butyl-N'-ethylcarbodiimide (BEC), N,N'-dicyclopentylcarbodiimide (CPC), bis(4-(2,2-dimethyl-1,3-dioxolane))methylcarbodiimide (BDDC), N-ethyl-N'-phenylcarbodiimide (PEC), and N-phenyl-N'-isopropylcarbodiimide (PIC). Ammonium coupling reagents include O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate (TBTU) or 1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxide hexafluorophosphate (HATU), O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HBTU), 3-(diethylphosphoryloxy)-1,2,3-benzotriazin-4(3H)-one (DEPBT), O-(6-chlorobenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HCTU), and O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate (TATU). Urea-based reagents include O-(5-norbornene-2,3-dicarboximide)-N,N,N',N'-tetramethyluronium tetrafluoroborate (TNTU) and O-(N-succinimidyl)-1,1,3,3-tetramethyluronium tetrafluoroborate (TSTU), O-(3,4-dihydro-4-oxo-1,2,3-benzotriazol-3-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate (TDBTU), O-(1,2-dihydro-2-oxo-1-pyridyl)-N,N,N',N'-tetramethyluronium tetrafluoroborate (TPTU), or O-[(ethoxycarbonyl)cyano-methyleneamino]-N,N,N',N'-tetramethyluronium tetrafluoroborate (TOTU).Phosphonium coupling reagents include (7-azabenzotriazol-1-yloxy)tripyrrolidinylphosphonium hexafluorophosphate (PyAOP), benzotriazol-1-yloxy-tris(dimethylamino)phosphonium hexafluorophosphate (BOP), (benzotriazol-1-yloxy)tripyrrolidinylphosphonium hexafluorophosphate (PyBOP), tripyrrolidinylphosphonium bromide hexafluorophosphate (PyBrOP), bis(2-oxo-3-oxazolidinyl)phosphinyl chloride (BOP-Cl), 1-cyano-2-ethoxy-2-oxoethyleneaminooxy-tripyrrolidinyl-phosphonium hexafluorophosphate (PyOxim), and 6-chloro-benzotriazol-1-yloxy-tripyrrolidinylphosphonium hexafluorophosphate (PyClock). Other reagents include, but are not limited to, 3-(diethylphosphoryloxy)-1,2,3-benzotriazin-4(3H)-one (DEPBT), N,N,N',N'-tetramethylchloroformamidine hexafluorophosphate (TCFH), or propylphosphonic anhydride solution. Anhydride coupling reagents include symmetrical anhydrides, mixed carbonic anhydrides, N-carboxylic anhydrides, and carbamate-protected N-carboxylic anhydrides. Additives used with carbodiimide coupling reagents include ethyl cyanohydroxyiminoacetate (Oxyma Pure), 1-hydroxy-7-azabenzotriazole (HOAt), hydroxybenzotriazole (HOBt), 2-hydroxypyridine-N-oxide (HOPO), N-hydroxysuccinimide (HOSu), 5-(hydroxyimino)-1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione (Oxyma B), hexafluoroisopropanol (HFIP), and 4-nitrophenyl alcohol.

[0056] A base may be used in the amide bond forming step. The base may be a tertiary amine base. Suitable bases include those selected from the group consisting of N-methylmorpholine (NMM), diisopropylethylamine (DIPEA), 1,4-diazabicyclo[2.2.2]octane (DABCO), diethylamine (DEA), triethylamine (TEA), and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU).

[0057] Suitable solvents for the amide coupling reaction include, but are not limited to, solvents selected from the group consisting of acetonitrile (MeCN), methyltetrahydrofuran (e.g., 2-methyltetrahydrofuran (MeTHF)), dimethyl sulfoxide (DMSO), ethyl acetate (EtOAc), dimethylformamide (DMF), tetrahydrofuran (THF), dimethylacetamide (DMA), N-methyl-2-pyrrolidine (NMP), water, and alkyl alcohols such as methanol, ethanol, and 2-propanol.

[0058] General synthetic scheme

[0059] The following scheme (Scheme A) may be used as a reference for the symbols used throughout the following description.

[0060]

[0061] As used in Scheme A and elsewhere herein, X1a, X2a, X3a, X4a, X5a, X6a, X7a, X8a, X9a, X10a, X11a, X12a, X13a, X14a, X15a, X16a, X17a, X18a, and X19a represent amino acid residues optionally protected by suitable protecting groups. The bridge used in Formula III, II, and I refers to the cyclization of the amino acid residues at positions X4a and X9a or X4 and X9. The amino acid residue is a divalent group having the structure -NHCRC(O)-, where R is an amino acid side chain. The amino acid side chain may contain reactive functional groups such as amino groups, hydroxyl groups, carboxyl groups, and thiol groups, which may be masked using suitable protecting groups during the coupling reaction of the peptide fragment. For example, when X4a is "Pen", this includes Pen amino acid residues protected by suitable protecting groups, such as Pen(Trt) and Pen(Acm). Suitable protecting groups are described in "Amino Acid-Protecting Groups", A. Isidro-Llobet, M. Alvarez, F. Albericio; Chem. Rev., 2009, Vol. 109, pp. 2455-2504. Protecting groups can be removed at a convenient subsequent stage using methods known in the art. X1, X2, X3, X4, X5, X6, X7, X8, X9, X10, X11, X12, X13, X14, X15, X16, X17, X18 and X19 represent unprotected amino acid residues. For example, when X4 is "Pen", this represents an unprotected (or deprotected) Pen amino acid residue.

[0062] The amino acid residues include amino acid residues selected from the group consisting of Gly, Ala, β-Ala, Leu, Met, Phe, Phe substituted with halo, alkyl, haloalkyl, hydroxy, alkoxy, cyano, cycloalkyl, carboxyl, carboxamido, 2-aminoethoxy (2-ea) or 2-acetamidoethoxy, Trp, Trp substituted with cyano, halo, alkyl, haloalkyl, hydroxy, substituted or unsubstituted aryl or alkoxy, Lys, Gln, β-heptyl omoGln, Pro, Val, Ile, Cys, (D) Cys, α-MeCys, (D) Pen, Pen or Pen (sulfoxide), Cit, Tyr, His, (D) His, Arg, (D)Arg, Asn, Glu, Ser, α-MeSer, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, α-MeThr, Lys(Ac), α-MeLy s(Ac), α-MeArg, α-MePhe, α-MeTyr, Dab(Ac), Dap(Ac), homo-Lys(Ac), Asp, Thr, Sarc, Aib, Dab, Dap, γ-Glu, Gaba, β-Pro, Abu, 1Nal, 2Nal, Lys(b-Ala), Lys(Gly), Lys(benzyl,Ac), Lys(butyl,Ac), Lys( isobutyl, Ac), Lys(propyl, Ac), Lys(PEG2PEG2gEC18OH), Phe(2ea), Phe(2-Me), Phe(3-Me), Phe(4-Me), Phe(3,4-dimethoxy), 2Quin, 3Quin, 4-amino-4-carboxytetrahydropyran (Gly(THP)), Acvc, cyclohexylAla, 2Pal, 3Pal or 4Pal, 5Pyal.

[0063] In any of the formulae disclosed herein, such as any of Formulae II to XIV, X3a is absent or is any amino acid residue. In some embodiments, X3a is absent. In some embodiments, X3a is Arg or D(Arg). In some embodiments, X3a is (D)Arg. The functional groups on the side chain of X3a may optionally be protected with a suitable protecting group.

[0064] In any of the formulae disclosed herein, for example, any of Formulae II to XIV, X4a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide). In some embodiments, X4a is Abu. In some embodiments, X4a is Cys or (D)Cys. In some embodiments, X4a is Pen or (D)Pen. In some embodiments, X4a is Pen. The functional groups on the side chains of X4a may optionally be protected with suitable protecting groups.

[0065] In any of the formulae disclosed herein, for example, any of Formulae II to XIV, X5a is Cit, Glu, Gly, substituted Gly, Leu, Ile, β-Ala, Ala, Lys, Asn, Pro, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, Lys(Ac), α-MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), Gln, Asp, or Cys. The functional groups on the side chain of X5a may be optionally protected with suitable protecting groups.

[0066] In any of the formulae disclosed herein, for example, any of Formulae II to XIV, X is Thr, 2-aminoisobutyric acid, Asp, Dab, Gly, Pro, Ser, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, α-MeThr, α-MeSer, or Val. The functional groups on the side chain of X can be optionally protected with a suitable protecting group.

[0067] In any of the formulas disclosed herein, such as any of Formulas II to XIV, X is unsubstituted Trp, or Trp substituted with cyano, halo, alkyl, substituted or unsubstituted aryl, haloalkyl, hydroxyl, or alkoxy. In any of the formulas disclosed herein, such as any of Formulas II to XIV, X is unsubstituted Trp, or Trp substituted with cyano, halo, alkyl, phenyl, or phenyl substituted with NHC(O)CH3, haloalkyl, hydroxyl, or alkoxy. The functional groups on the side chain of X may optionally be protected with suitable protecting groups.

[0068] In any of the formulae disclosed herein, for example, any of Formulae II to XIV, X is Gln, α-Me-Lys, α-MeLeu, α-MeLys(Ac), β-homoGln, Cit, Glu, Phe, Asn, Thr, Val, 2-aminoisobutyric acid, α-MeGln, α-MeAsn, Lys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), 1-Nal, 2Nal, or Trp. The functional groups on the side chain of X can be optionally protected with a suitable protecting group.

[0069] In any of the formulae disclosed herein, for example, any of Formulae II to XIV, X9a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide). The functional groups on the side chains of X9a may be optionally protected with suitable protecting groups.

[0070] In any of the formulae disclosed herein, for example, any of Formulae II to XIV, X10a is unsubstituted Phe, or Phe substituted with halo, alkyl, haloalkyl, hydroxy, alkoxy, carboxyl, carboxamido, 2-aminoethoxy, or 2-acetylaminoethoxy. The functional groups on the side chain of X10a may optionally be protected with a suitable protecting group.

[0071] In any of the formulae disclosed herein, for example, any of Formulae II to XIV, X11a is 2Nal, unsubstituted Trp, or Trp substituted with cyano, halo, alkyl, haloalkyl, hydroxy, alkoxy, Phe(2-Me), Phe(3-Me), Phe(4-Me), Phe(3,4-dimethoxy), or 1Nal. The functional groups on the X11a side chain may optionally be protected with a suitable protecting group.

[0072] In any of the formulae disclosed herein, for example, any of Formulae II to XIV, X is 4-amino-4-carboxy-tetrahydropyran (Gly(THP)), α-MeLys, α-MeLeu, α-MeArg, α-MePhe, α-MeLeu, α-MeLys, α-MeAsn, α-MeTyr, Ala or cyclohexylAla, Lys or 2-aminoisobutyric acid. The functional groups on the side chain of X can be optionally protected with a suitable protecting group.

[0073] In any of the formulae disclosed herein, for example, any of Formulae II to XIV, X13a is 2-aminoisobutyric acid, Glu, Cit, Gln, Lys(Ac), α-MeArg, α-MeGlu, α-MeLeu, α-MeLys, α-Me-Asn, α-MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), or Lys; or X13a is Lys, pegylated Lys, b-homoGlu, or Lys(Y2-Ac), wherein Y2 is an amino acid residue. The functional group on the side chain of X13a may optionally be protected with a suitable protecting group.

[0074] In any of the formulae disclosed herein, for example, any of Formulae II to XIV, X14a is Asn, 2Nal, 2-aminoisobutyric acid, Arg, Cit, Asp, Phe, Gly, Lys, Leu, Ala, (D)Ala, β-Ala, His, Thr, n-Leu, Gln, Ser, (D)Ser, Tic, Trp, α-MeGln, α-MeAsn, α-MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), or Lys(Ac). The functional groups on the X14a side chain may be optionally protected with a suitable protecting group.

[0075] In any of the formulae disclosed herein, for example, any of Formulae II to XIV, X is Ala, β-Ala, Arg, Asn, Asp, Cit, Cys, Glu, Gln, Gly, substituted or unsubstituted His, (D)His, Ile, Lue, (D)Lue, Lys, (D)Lys, Met, 2Pal, 3Pal or 4Pal, Phe, Pro, 5-Pyal, 2Quin, 3Quin, Ser, Thr, Trp, Tyr, Val, or Leu. The functional groups on the X side chain may be optionally protected with suitable protecting groups.

[0076] In any of the formulae disclosed herein, for example, any of Formulae II to XIV, X16a is absent or is Sarc, aMeLeu, (D)NMeTyr, His, (D)Thr, bAla, Pro, or (D)Pro. The functional groups on the X16a side chain may be optionally protected with a suitable protecting group.

[0077] In any of the formulae disclosed herein, X17a is absent or is Lys(PEG2PEG2gEC18OH). The functional groups on the X17a side chain may be optionally protected with a suitable protecting group.

[0078] Suitable amino protecting groups include benzyl (Bn), trityl (Trt), 4-methyltrityl (Mtt), β-methoxyethoxytrityl (MEM), 2-nitrophenylsulfonyl (Nps), 2-(4-nitrophenyl)sulfonylethoxycarbonyl (Nsc), benzothiazole-2-sulfonyl (Bts), dithiasuccinyl (Dts), nitrobenzenesulfonyl (Ns), 2-(2-nitrophenyl)propyloxycarbonyl (N PPOC), 2-(3,4-methylenedioxy-6-nitrophenyl)propoxycarbonyl (MNPPOC), methylsulfonylethoxycarbonyl (Msc), 9-fluorenylmethyloxycarbonyl (Fmoc), 2,7-di-tert-butyl-Fmoc (Fmoc*), 2-fluoro-Fmoc (Fmoc(2F)), 2-monoisooctyl-Fmoc (mio-Fmoc), benzyloxycarbonyl (Cbz), 2,2,2-trichloro Ethoxycarbonyl (Troc), 2-(trimethylsilyl)ethoxycarbonyl (Teoc), 2-(4-trifluoromethylphenylsulfonyl)ethoxycarbonyl (Tsc), tert-butoxycarbonyl (BOC), 1-adamantyloxycarbonyl (Adoc), 2-adamantyloxycarbonyl (2-Adoc), 2,4-dimethylpentan-3-yloxycarbonyl (Doc), cyclohexyloxycarbonyl (Hoc), 1,1-dimethyl-2,2,2-trichloroethoxycarbonyl (TcBOC), formyl, acetyl (Ac), trifluoroacetyl (TFA), p-toluenesulfonyl (Ts), vinyl, 2-chloroethyl, 2-phenylsulfonylethyl, allyl, 2-nitrobenzyl, 4-nitrobenzyl, diphenyl-4-pyridylmethyl, N',N'-dimethylhydrazine, methoxymethyl, tert-butoxymethyl (Bum), benzyloxymethyl (BOM), 2-tetrahydropyranyl (THP), tris(C 1-4alkyl) silyl (e.g., tri(isopropyl)silyl), 1,1-diethoxymethyl, α,α-dimethyl-3,5-dimethoxybenzyloxycarbonyl (Ddz), 2-(p-biphenyl)-2-propoxycarbonyl (Bpoc), 1,1-dioxonaphtho[1,2-b]thiophene-2-methyloxycarbonyl (α-Nsmoc), 3,3-dioxonaphtho[2,1-b]thiophene-2-methyloxycarbonyl (β-Nsmoc), 1-(4,4-dimethyl-2,6-dioxocyclohexan-1-ylidene)ethyl (Dde), 1-(4,4-dimethyl-2,6-dioxocyclohexan-1-ylidene)ethyl)

[0014] In some embodiments, the present invention may include phenyldithioethoxycarbonyl (ivDde), 2-(phenyl(methyl)sulfonium)ethoxycarbonyl (Pms), N-ethylsulfonylethoxycarbonyl (Esc), 2-(4-sulfophenylsulfonyl)ethoxycarbonyl (Sps), allyloxycarbonyl (Alloc), propargyloxycarbonyl (Poc), 9-(4-bromophenyl)-9-fluorenyl (BrPhF), azidomethoxycarbonyl (Azoc), N-tetrachlorophthaloyl (TCP), phenyldithioethoxycarbonyl (Phdec), 2-pyridyldithioethoxycarbonyl (Pydec), or N-pivaloyloxymethyl (POM).

[0079] Suitable carboxyl protecting groups are selected from C 1-6 Alkyl (such as tert-butyl (tBu), methyl (Me), ethyl (Et), propyl and cyclohexyl), allyl, 1,1-dimethylallyl (Dma), benzoyl (Pac), p-nitrobenzyl (p-NB), trityl (Tr), 2-chlorotrityl (2-Cl-Trt), 2,4-dimethoxybenzyl (Dmb), 9-fluorenylmethyl (Fm), phenyl, cyclohexyl, benzyl (Bn), 3,4-ethylenedioxy-2-thienyl (EDOT n ), 4-(N-(1-(4,4-dimethyl-2,6-dioxocyclohexylidene)-3-methylbutyl)amino)benzyl (Dmab), trimethylsilylethyl (TMSE), 2-(trimethylsilyl)isopropyl (Tmsi), 2,2,2-trichloroethyl (Tce), carbamoylmethyl (Cam), 4,5-dimethoxy-2-nitrobenzyloxycarbonyl (Dmnb), pentaamminecobalt(III), β-menthyl (Men), β-3-menthylpentan-3-yl (Mpe), or 2-phenylisopropyl (2-Ph(iPr)). In the case where the carboxyl protecting group also serves as a leaving group in the amide coupling, the carboxyl protecting group may be p-nitrobenzyl.

[0080] Suitable thiol protecting groups include p-methylbenzyl (Meb), p-methoxybenzyl (Mob), trityl (Tr), monomethoxytrityl (Mmt), 2,4,6-trimethoxybenzyl (Tmob), 9-xanthenyl (Xan), 2,2,4,6,7-pentamethyl-5-dihydrobenzofuranylmethyl (Pmbf), benzyl (Bn), tert-butyl (tBu), 1-adamantyl (1-Ada), 9-fluorenylmethyl (Fm), 2-(2,4-dinitrophenyl)ethyl (Dn pe), 9-fluorenylmethyloxycarbonyl (Fmoc), acetylaminomethyl (Acm), phenylacetylaminomethyl (PhAcm), tert-butylthio (S(tBu)), 3-nitro-2-pyridylsulfinyl (Npys), 2-pyridylsulfinyl (S-Pyr), allyloxycarbonyl (Alloc), N-allyloxycarbonyl-N-[2,3,5,6-tetrafluoro-4-(phenylthio)phenyl]aminomethyl (Fsam), o-nitrobenzyl (o-NB), 4-pyridylmethyl, and ninhydrin (Nin).

[0081] Suitable hydroxy protecting groups include benzyl (Bn), cyclohexyl, tert-butyl (tBu), trityl (Trt), tert-butyldimethylsilyl (TBDMS), pseudoproline, tert-butyldiphenylsilyl (TBDPS), 4,5-dimethoxy-2-nitrobenzyloxycarbonyl (Dmnb), propargyloxycarbonyl (Poc).

[0082] abbreviation

[0083] Herein and throughout this application, the following abbreviations may be used.

[0084] Ac acetyl

[0085] Acm acetylaminomethyl

[0086] ACN or MeCN Acetonitrile

[0087] AcOH acetic acid

[0088] 1-Ada 1-adamantyl

[0089] Adoc 1-adamantyloxycarbonyl

[0090] 2-Adoc 2-adamantyloxycarbonyl

[0091] Alloc Allyloxycarbonyl

[0092] API active pharmaceutical ingredient

[0093] Azoc azidomethoxycarbonyl

[0094] BDDC Bis[[4-(2,2-dimethyl-1,3-dioxolane)]methylcarbodiimide

[0095] BEC N-tert-butyl, N'-ethylcarbodiimide

[0096] BMC N-tert-butyl, N'-methylcarbodiimide

[0097] Bn benzyl

[0098] Boc or BOC tert-butoxycarbonyl

[0099] BOP Benzotriazol-1-yloxy-tris(dimethylamino)phosphonium hexafluorophosphate

[0100] BOP-Cl Bis(2-oxo-3-oxazolidinyl)phosphinyl chloride

[0101] Bpoc 2-(p-biphenyl)-2-propoxycarbonyl

[0102] BOM benzyloxymethyl

[0103] BrPhF 9-(4-bromophenyl)-9-fluorenyl

[0104] BSA Bis(trimethylsilyl)acetamide

[0105] Bts benzothiazole-2-sulfonyl

[0106] Bum tert-Butoxymethyl

[0107] Bz benzoyl

[0108] Cam carbamoylmethyl

[0109] Cbz or Z benzyloxycarbonyl

[0110] CDI 1,1'-Carbonyldiimidazole

[0111] CIC N-cyclohexyl, N'-isopropylcarbodiimide

[0112] 2-Cl-Trt 2-Chlorotrityl

[0113] CPC N,N'-dicyclopentylcarbodiimide

[0114] DABCO 1,8-diazabicyclo[2.2.2]octane

[0115] DBU 1,8-diazabicyclo[5,4,0]undec-7-ene

[0116] DCC N-N'-dicyclohexylcarbodiimide

[0117] DCHA Dicyclohexylamine

[0118] DCM dichloromethane

[0119] Dde 1-(4,4-dimethyl-2,6-dioxocyclohexan-1-ylidene)ethyl

[0120] ivDde 1-(4,4-dimethyl-2,6-dioxocyclohexan-1-ylidene)isovaleryl

[0121] Ddz α,α-dimethyl-3,5-dimethoxybenzyloxycarbonyl

[0122] DEA Diethylamine

[0123] DEPBT 3-(Diethylphosphoryloxy)-1,2,3-benzotriazin-4(3H)-one

[0124] DIC Diisopropylcarbodiimide

[0125] DIEA, DIPEA N,N-diisopropylethylamine

[0126] DMA (Solvent) Dimethylacetamide

[0127] Dma 1,1-dimethylallyl

[0128] Dmab 4-(N-[1-(4,4-dimethyl-2,6-dioxocyclohexylidene)-3-methylbutyl)amino)benzyl

[0129] Dmb 2,4-dimethoxybenzyl

[0130] DMF N,N-dimethylformamide

[0131] Dmnb 4,5-dimethoxy-2-nitrobenzyloxycarbonyl

[0132] DMSO dimethyl sulfoxide

[0133] Dnpe 2-(2,4-dinitrophenyl)ethyl

[0134] Doc 2,4-dimethylpentan-3-yloxycarbonyl

[0135] DODT 3,6-dioxa-1,8-octanedithiol

[0136] Dts dithiosuccinyl

[0137] EDC N-ethyl-N'-dimethylaminopropylcarbodiimide

[0138] EDCI N-ethyl-N'-(3-dimethylaminopropyl)carbodiimide

[0139] Esc N-Ethylsulfonylethoxycarbonyl

[0140] EDOTn 3,4-ethylenedioxy-2-thienyl

[0141] ESI-MS electrospray ionization mass spectrometry

[0142] Et ethyl

[0143] EtOAc

[0144] EtOH

[0145] Fm fluorenylmethyl

[0146] Fmoc 9-fluorenylmethoxycarbonyl

[0147] Fmoc* 2,7-di-tert-butyl-Fmoc

[0148] Fmoc(2F) 2-Fluoro-Fmoc

[0149] mio-Fmoc 2-monoisooctyl-Fmoc

[0150] Fsam N-allyloxycarbonyl-N-[2,3,5,6-tetrafluoro-4-(phenylthio)phenyl]aminomethyl

[0151] HATU 1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxide hexafluorophosphate

[0152] HBTU O-(Benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate

[0153] HCTU O-(6-chlorobenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate

[0154] HFIP hexafluoroisopropanol

[0155] HOAt 1-Hydroxy-7-azabenzotriazole

[0156] HOBt Hydroxybenzotriazole

[0157] Hoc cyclohexyloxycarbonyl

[0158] HOPO 2-Hydroxypyridine-N-oxide

[0159] HOSu N-hydroxysuccinimide

[0160] HPLC high-performance liquid chromatography

[0161] HV High Vacuum

[0162] IBD Inflammatory Bowel Disease

[0163] IL-23 Interleukin-23

[0164] IPA Isopropyl alcohol

[0165] IPAc isopropyl acetate

[0166] IPC Process Control

[0167] IPE Isopropyl Ether

[0168] Me methyl

[0169] Meb p-methylbenzyl

[0170] MEM β-Methoxyethoxytrityl

[0171] Men β-menthyl

[0172] MeOH methanol

[0173] MeTHF 2-Methyltetrahydrofuran

[0174] Mmt monomethoxytrityl

[0175] MNPPOC 2-(3,4-methylenedioxy-6-nitrophenyl)propoxycarbonyl

[0176] Mob p-methoxybenzyl

[0177] MOM methoxymethyl

[0178] Moz p-methylbenzyloxycarbonyl

[0179] Mpe β-3-menthylpentyl-3-yl

[0180] Mr relative molecular weight

[0181] Msc methylsulfonylethoxycarbonyl

[0182] MTBE methyl tert-butyl ether

[0183] Mtt 4-Methyltrityl

[0184] m / z mass-to-charge ratio

[0185] NB Nitrobenzyl

[0186] Ninhydrin

[0187] NMM N-Methylmorpholine

[0188] NMP N-Methylpyrrolidine

[0189] NMR Nuclear Magnetic Resonance

[0190] NPPOC 2-(2-nitrophenyl)propoxycarbonyl

[0191] Nps 2-nitrophenylsulfonyl

[0192] Npys 3-nitro-2-pyridinesulfinyl

[0193] Ns Nitrobenzenesulfonyl

[0194] Nsc 2-(4-nitrophenyl)sulfonylethoxycarbonyl

[0195] α-Nsmoc 1,1-dioxonaphtho[1,2-b]thiophene-2-methyloxycarbonyl

[0196] β-Nsmoc 3,3-dioxonaphtho[2,1-b]thiophene-2-methyloxycarbonyl

[0197] OEt Ethoxy

[0198] OHe hexyloxy

[0199] OMe methoxy

[0200] OPac oxyphenylacetyl

[0201] Oxyma B 5-(Hydroxyimino)-1,3-dimethylpyrimidine-2,4,6-(1H,3H,5H)-trione

[0202] Oxyma Pure ethyl 2-cyano-2-(hydroxyimino)acetate

[0203] Pac benzoyl

[0204] Pbf 2,2,4,6,7-pentamethyldihydrobenzofuran-5-sulfonyl

[0205] PEC N-ethyl, N-phenylcarbodiimide

[0206] PhAcm phenylacetylaminomethyl

[0207] Phdec phenyldithioethoxycarbonyl

[0208] 2-Ph(iPr) 2-phenylisopropyl

[0209] PIC N-phenyl, N-isopropylcarbodiimide

[0210] PivCl Pivaloyl chloride

[0211] Pmbf 2,2,4,6,7-pentamethyl-5-dihydrobenzofuranylmethyl

[0212] Pms 2-(phenyl(methyl)sulfonium)ethoxycarbonyl

[0213] Poc propargyloxycarbonyl

[0214] POM N-pivaloyloxymethyl

[0215] 1-PrOH 1-propanol

[0216] PyAOP (7-azabenzotriazol-1-yloxy)tripyrrolidinophosphonium hexafluorophosphate

[0217] PyBOP (Benzotriazol-1-yloxy)tripyrrolidinophosphonium hexafluorophosphate

[0218] PyBrOP Trispyrrolidinylphosphonium bromide hexafluorophosphate

[0219] Pydec 2-pyridyldithioethoxycarbonyl

[0220] rt or RT room temperature

[0221] Sps 2-(4-sulfophenylsulfonyl)ethoxycarbonyl

[0222] S-Pyr 2-pyridinesulfinyl

[0223] S(tBu) tert-butylthio

[0224] TATU O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate

[0225] TBDMS tert-butyldimethylsilyl

[0226] TBDPS tert-Butyldiphenylsilyl

[0227] TBS tert-Butyldimethylsilyl

[0228] TBTU N,N,N'N'-Tetramethyl-O-(benzotriazol-1-yl)ammonium tetrafluoroborate

[0229] tBu tert-butyl

[0230] TcBOC 1,1-dimethyl-2,2,2-trichloroethoxycarbonyl

[0231] Tce 2,2,2-trichloroethyl

[0232] TCFH N,N,N',N'-Tetramethylchloroformamidine hexafluorophosphate

[0233] TCP N-Tetrachlorophthaloyl

[0234] TDBPTU O-(3,4-dihydro-4-oxo-1,2,3-benzotriazol-3-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate

[0235] TEA triethylamine

[0236] Teoc 2-(trimethylsilyl)ethoxycarbonyl

[0237] TES triethylsilyl

[0238] TFA trifluoroacetyl

[0239] THF Tetrahydrofuran

[0240] THP 2-Tetrahydropyranyl

[0241] TIS triisopropylsilane

[0242] Tmob 2,4,6-trimethoxybenzyl

[0243] TMS trimethylsilyl

[0244] TMSE trimethylsilylethyl

[0245] Tmsi 2-(trimethylsilyl)isopropyl

[0246] TNTU O-(5-norbornene-2,3-dicarboximide)-N,N,N',N'-tetramethyluronium tetrafluoroborate

[0247] TOTU O-[(Ethoxycarbonyl)cyano-methyleneamino]-N,N,N',N'-tetramethyluronium tetrafluoroborate

[0248] TPP Thiamine pyrophosphate

[0249] TPTU O-(1,2-dihydro-2-oxo-1-pyridinyl)-N,N,N',N'-tetramethyluronium tetrafluoroborate

[0250] Tr triphenylmethyl

[0251] Troc 2,2,2-trichloroethoxycarbonyl

[0252] TrtOH Triphenylmethanol

[0253] Ts p-Toluenesulfonyl

[0254] Tsc 2-(4-trifluoromethylphenylsulfonyl)ethoxycarbonyl

[0255] TSTU O-(N-succinimidyl)-1,1,3,3-tetramethyluronium tetrafluoroborate

[0256] UPLC high-performance liquid chromatography

[0257] v / v volume:volume

[0258] w / w weight:weight

[0259] Xan 9-Xanthenyl

[0260] G Glycine Gly P Proline Pro

[0261] A Alanine Ala V Valine Val

[0262] L Leucine Leu I Isoleucine Ile

[0263] M Methionine Met C Cysteine Cys

[0264] F Phenylalanine Phe Y Tyrosine Tyr

[0265] W Tryptophan Trp H Histidine His

[0266] K Lysine Lys R Arginine Arg

[0267] Q Glutamine Gln N Asparagine Asn

[0268] E Glutamic acid Glu D Aspartic acid Asp

[0269] S Serine T Threonine Thr

[0270]

[0271]

[0272]

[0273]

[0274] definition

[0275] Unless otherwise defined herein, scientific and technical terms used in this application shall have the meanings commonly understood by one of ordinary skill in the art.

[0276] As used herein, the following terms have the meanings ascribed to them unless otherwise indicated.

[0277] "A" and "an" are indefinite articles and when used herein to refer to a group of substituents or a "substituent group" mean at least one.

[0278] When referring to a value, "about" includes the value of the value + / - 10%. For example, about 50% includes the range of 45% to 55%, and about 20 molar equivalents includes the range of 18 molar equivalents to 22 molar equivalents. Therefore, when referring to a range, "about" refers to the value of each of the two ends of the range + / - 10%. For example, a ratio of about 1 to about 3 (weight / weight) includes a range of 0.9 to 3.3. In some embodiments, a reference to about a value or parameter includes a description of the value or parameter itself. For example, a reference to about 20 molar equivalents includes and describes 20 molar equivalents itself.

[0279] As used in the specification and claims, as used herein, "comprises," "including," "has," "may," "contains" and variations thereof are intended to be open transitional phrases, terms or words that require the presence of named features, groups, components or steps, but do not preclude the presence of other features, groups, components or steps. The terms "comprising," "including," "having," "may," or "containing" may include embodiments encompassed by the terms "consisting essentially of" or "consisting of.

[0280] The terms "peptide," "polypeptide," and "protein" are used interchangeably herein and generally refer to molecules comprising a chain of two or more amino acids (e.g., L-amino acids, D-amino acids, modified amino acids, amino acid analogs, amino acid mimetics, etc.).

[0281] As used herein, the term "L-amino acid" refers to the "L" isomeric form of an amino acid, and conversely the term "D-amino acid" refers to the "D" isomeric form of an amino acid (e.g., (D)Asp or D-Asp; (D)Phe or D-Phe). An amino acid residue in the D isomeric form can replace any L-amino acid residue as long as the peptide retains the desired function. When referred to using single-letter abbreviations, D-amino acids can be indicated in lower case as per convention. L-amino acids can be represented by conventional three-letter, uppercase single letters, or the amino acid designation described in the abbreviation. For example, D-arginine can be represented as "arg" or "r". Alternatively, "D" or a lowercase "d" in front of an amino acid can be used to indicate that it is in the D isomeric form, for example, D-lysine can be represented by dK. As another example, L-arginine can be represented as "Arg" or "R".

[0282] Those skilled in the art will appreciate that certain amino acids and other chemical moieties are modified when combined with another molecule. For example, an amino acid side chain can be modified when forming an intramolecular bridge with another amino acid side chain, for example, one or more hydrogens can be removed or replaced by a bond.

[0283] As used herein, the term "NH2" may refer to the free amino group present at the amino terminus of a polypeptide. As used herein, the term "OH" may refer to the free carboxyl group present at the carboxyl terminus of a peptide. Additionally, as used herein, the term "Ac" refers to acetyl protection by acylation of the C-terminus or N-terminus of a polypeptide. In certain peptides shown herein, the NH2 at the C-terminus of the peptide indicates an amino group.

[0284] As used herein, the term "carboxyl" refers to -CO2H.

[0285] As used herein, the term "cyclization" refers to the joining of one part of a polypeptide molecule to another part of a polypeptide molecule to form a closed ring, such as by forming a disulfide bridge or a thioether bond to form a closed ring.

[0286] As used herein, the term "subunit" refers to one of a pair of polypeptide monomers that join to form a dimeric peptide composition.

[0287] As used herein, the term "salt" or "pharmaceutically acceptable salt" refers to a salt or zwitterionic form of a peptide or compound of the present invention that is water-soluble or oil-soluble or dispersible, suitable for treating a disease without excessive toxicity, irritation, and allergic response; commensurate with a reasonable benefit / risk ratio, and effective for its intended use. Salts can be prepared during the final isolation and purification of the compound or separately by reacting an amino group with a suitable acid. Representative acid addition salts include acetate, adipate, alginate, citrate, aspartate, benzoate, benzenesulfonate, bisulfate, butyrate, camphorate, camphorsulfonate, digluconate, glycerophosphate, hemisulfate, heptanoate, hexanoate, formate, fumarate, hydrochloride, hydrobromide, hydroiodide, 2-hydroxyethanesulfonate (isethionate), lactate, maleate, mesitylenesulfonate, methanesulfonate, naphthylenesulfonate, nicotinate, 2-naphthalenesulfonate, oxalate, pamoate, pectinate, persulfate, 3-phenylpropionate, picrate, pivalate, propionate, succinate, tartrate, trichloroacetate, trifluoroacetate, phosphate, glutamate, bicarbonate, p-toluenesulfonate, and undecanoate. Similarly, amino groups in the compounds of the present invention can be quaternized with methyl, ethyl, propyl, and butyl chlorides, bromides, and iodides; dimethyl, diethyl, dibutyl, and dipentyl sulfates; decyl, lauryl, myristyl, and steryl chlorides, bromides, and iodides; and benzyl and phenethyl bromides. Examples of acids that can be used to form therapeutically acceptable addition salts include inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, and phosphoric acid, and organic acids such as oxalic acid, maleic acid, succinic acid, and citric acid. The salt can be suitably a selected salt, such as an acid addition salt and a basic salt. Examples of acid addition salts include chloride salts, citrates, and acetates. Examples of basic salts include salts in which the cation is selected from alkali metal cations such as sodium or potassium, alkaline earth metal cations such as calcium or magnesium, and substituted ammonium ions such as ions of the type N(R1)(R2)(R3)(R4)+, wherein R1, R2, R3 and R4 are independently selected from hydrogen, optionally substituted C 1-6 -alkyl or optionally substituted C 2-6- Alkenyl. Related C 1-6 Examples of -alkyl groups include methyl, ethyl, 1-propyl and 2-propyl groups. 2-6Examples of -alkenyl groups include vinyl, 1-propenyl, and 2-propenyl. Other examples of pharmaceutically acceptable salts are described in "Remington's Pharmaceutical Sciences," 17th edition, Alfonso R. Gennaro (ed.), Mark Publishing Company, Easton, PA, USA, 1985 (and its latest edition), "Encyclopaedia of Pharmaceutical Technology," 3rd edition, James Swarbrick (ed.), Informa Healthcare USA (Inc.), NY, USA, 2007, and J. Pharm. Sci. Vol. 66: p. 2, 1977. Similarly, for a review of suitable salts, see Handbook of Pharmaceutical Salts: Properties, Selection, and Use, by Stahl and Wermuth (Wiley-VCH, 2002). Other suitable base salts are formed from bases that form non-toxic salts. Representative examples include aluminum, arginine, benzathine, calcium, choline, diethylamine, diethanolamine, glycine, lysine, magnesium, meglumine, olamine, potassium, sodium, tromethamine, and zinc salts. Hemisalts of acids and bases can also be formed, such as hemisulphate and hemicalcium salts.

[0288] By "pharmaceutically acceptable" is meant that the carrier, diluent or excipient must be compatible with the other components or ingredients of the composition of the present invention, i.e., it is useful, safe, non-toxic, and acceptable for pharmaceutical use. According to the present invention, pharmaceutically acceptable means approved or approvable for use in animals, and more particularly in humans, as listed in the United States Pharmacopoeia or other generally recognized pharmacopeia.

[0289] The term "alkyl" includes straight or branched, acyclic or cyclic saturated aliphatic hydrocarbons containing 1 to 24 carbon atoms. Representative saturated straight-chain alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, and the like, while saturated branched-chain alkyl groups include, but are not limited to, isopropyl, sec-butyl, isobutyl, tert-butyl, isopentyl, and the like. Representative saturated cyclic alkyl groups include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and the like, while unsaturated cyclic alkyl groups include, but are not limited to, cyclopentenyl, cyclohexenyl, and the like.

[0290] "Halo" or "halogen" refers to a bromo (Br), chloro (Cl), fluoro (F), or iodo (I) substituent.

[0291] The term "haloalkyl" includes alkyl structures in which at least one hydrogen is replaced by a halogen atom. In certain embodiments in which two or more hydrogen atoms are replaced by halogen atoms, the halogen atoms are all identical to one another. In other embodiments in which two or more hydrogen atoms are replaced by halogen atoms, the halogen atoms are not all identical to one another.

[0292] An "alkoxy" group refers to an (alkyl)O- group where alkyl is as defined herein.

[0293] "Aryl" refers to a monocyclic, bicyclic (fused) and tricyclic (fused or spiro) hydrocarbon ring system having a total of 5 to 14 ring carbon atoms, wherein at least one ring in the system is aromatic and wherein each ring in the system contains 3 to 7 ring carbon atoms. For example, "aryl" can be "phenyl". Substituted aryl includes aryl substituted with NHC(O)CH3. Substituted phenyl includes phenyl substituted with NHC(O)CH3.

[0294] Unless otherwise indicated, optional substituents include one or more groups selected from the group consisting of acetyl, NHC(O)CH3, alkyl, alkenyl, alkynyl, alkoxy, amino, nitro, CN, hydroxy, halo, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, and fluoroalkyl.

[0295] Generally speaking, "PEGn" associated with the number n comprises the formula: -[O-CH2CH2]n-, where n is the number of ethylene oxide units. For example, PEG2 refers to -[O-CH2CH2]2-.

[0296] Substituents are those that result in the formation of stable or chemically feasible compounds. As used herein, the term "stable" refers to compounds that do not undergo substantial alteration when subjected to conditions that allow the compound to be produced, detected, and preferably recovered, purified, and used for one or more of the purposes disclosed herein. In some embodiments, a stable compound or a chemically feasible compound is one that does not substantially change when kept at 40° C. or less in the absence of moisture or other chemically reactive conditions for at least one week.

[0297] The abbreviation "(v / v)" refers to the phrase "volume:volume," i.e., the ratio of a particular substance within a mixture, as measured by the volume or volume amount of a component of a composition disclosed herein relative to the total volume of the composition. Thus, the quantity is smaller in units and represents the volume percentage amount of the component relative to the total volume of the composition. For example, a 2% (v / v) solvent mixture may indicate that 2 mL of one solvent is present in 100 mL of the solvent mixture.

[0298] The abbreviation "(w / w)" refers to the phrase "weight:weight," i.e., the ratio of a particular substance within a mixture, as measured by the weight or mass or weight amount of a component of a composition disclosed herein relative to the total weight of the composition. Thus, the amount is smaller in units and represents the weight percent amount of the component relative to the total weight of the composition. For example, a 2% (w / w) solution may indicate that 2 grams of solute are dissolved in 100 grams of solution.

[0299] During any of the processes for the preparation of the compounds of the present invention, it may be necessary and / or desirable to protect sensitive or reactive groups in any of the molecules concerned. This may be achieved by conventional protecting groups such as those described in: Protective Groups in Organic Chemistry ”, JFW McOmie, ed., Plenum Press, 1973; and TW Greene and PGM Wuts, “ Protective Groups in Organic Synthesis ”, John Wiley & Sons, 1991 or “Amino Acid-Protecting Groups”, A. Isidro-Llobet, M. Alvarez, F. Albericio; Chem. Rev., 2009, Vol. 109, pp. 2455-2504. The protecting groups can be removed at a convenient subsequent stage using methods known in the art.

[0300] Protected amino acids or peptide fragments can be reacted with each other using coupling reagents such as those described in: "Peptide Coupling Reagents, More than a Letter Soup", A. El-Faham, A. Albericio; Chem. Rev., 2011, Vol. 111, pp. 6557-6602, or "Large-Scale Applications of Amide Coupling Reagents for the Synthesis of Pharmaceuticals", JR Dunetz, J. Magano, GA Weisenburger; Org. Process Res. Dev. 2016, Vol. 20, pp. 140-177.

[0301] Disulfide bonds can be formed using the method described in: “Disulfide Bond Formation in Peptides”, L. Chen, I. Annis, G. Barany; Current Protocols in Protein Science, 2001, 18.6.1-18.6.19.

[0302] Preparation of monocyclic peptides

[0303] Solid phase peptide synthesis (SPPS) involves connecting the starting peptide chain to a solid support and subsequently extending it through a series of extension cycles, with washing and purification, such as chromatography, between cycles. Due to the limitations of the SPPS equipment size and the need for chromatographic purification, it is often too expensive to produce peptides on a production scale of up to 10 kg. In contrast, the method for preparing monocyclic peptides as described herein utilizes solution phase chemistry, telescopic synthesis, and effective purification methods (such as extraction and crystallization of key intermediates) to achieve a yield of up to 10 kg. In particular, the method described herein provides a more cost-effective method than SPPS for large-scale manufacture of monocyclic peptides with 8 to 20 amino acid residues.

[0304] The present invention provides a method for preparing a monocyclic peptide or a salt thereof. The method comprises coupling a monocyclic peptide fragment with a linear peptide fragment, wherein the monocyclic peptide fragment is a peptide containing 4 to 11 amino acid residues; wherein the monocyclic peptide fragment comprises a ring containing 4 to 8 amino acid residues; wherein the linear peptide fragment is a peptide containing 4 to 10 amino acid residues; and wherein an amide bond is formed between the monocyclic peptide fragment and the linear peptide fragment.

[0305] The advantage of the method of the present invention is that the coupling of the single-ring peptide fragment and the linear peptide fragment can be carried out in a solution phase without the use of a solid support.

[0306] Another advantage of the method of the present invention is that it can be carried out on a large scale and is suitable for commercial production. In some embodiments, the method produces a single cyclic peptide in an amount greater than 1 Kg, particularly greater than 10 Kg, greater than 20 Kg, greater than 50 Kg, more particularly 10 Kg to 60 Kg.

[0307] Certain intermediates in the method can be separated to improve the overall purity and yield of the monocyclic peptide. In some embodiments, the method also includes separating and / or crystallizing one or more intermediates. In some embodiments, the method also includes separating and / or crystallizing one or more compounds selected from formula I, II, III, III', IV, V, V', VI, VII, VIII, IX, X, XI, XII, XIII and XIV. In some embodiments, the intermediate can be selected from compounds of formula (IV), formula (V) and formula (VI). In some embodiments, the method also includes separating and / or crystallizing compounds of formula (I), (II) and (III).

[0308] In some embodiments, an amide bond is formed between the amino acid residue at the C-terminus of the single-loop peptide fragment and the amino acid residue at the N-terminus of the linear peptide fragment. In an alternative embodiment, an amide bond is formed between the amino acid residue at the N-terminus of the single-loop peptide fragment and the amino acid residue at the C-terminus of the linear peptide fragment.

[0309] The coupling of the single-ring peptide fragment and the linear peptide fragment is carried out using any suitable amide coupling reagent. Non-limiting examples of coupling reagents include carbodiimide coupling reagents, carbodiimide coupling reagents with additives (activated esters), ammonium-based coupling reagents, urea-based reagents, phosphonium-based coupling reagents, halogenating reagents, acyl azoles, acyl azides, acid halides, organophosphorus reagents, organosulfur reagents, triazine coupling reagents, pyridinium coupling reagents, mixed anhydride reagents and activated esters.

[0310] Carbodiimide coupling reagents include N,N'-diisopropylcarbodiimide (DIC), N,N'-dicyclohexylcarbodiimide (DCC), 1,1'-carbonyldiimidazole (CDI), and N-ethyl-N'-dimethylaminopropylcarbodiimide (EDC), N-ethyl-N'(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCI), N-cyclohexyl-N'-isopropylcarbodiimide (CIC), N-tert-butyl-N'-methylcarbodiimide (BMC), N-tert-butyl-N'-ethylcarbodiimide (BEC), N,N'-dicyclopentylcarbodiimide (CPC), bis(4-(2,2-dimethyl-1,3-dioxolane))methylcarbodiimide (BDDC), N-ethyl-N'-phenylcarbodiimide (PEC), and N-phenyl-N'-isopropylcarbodiimide (PIC).

[0311] Ammonium coupling reagents include O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate (TBTU) or 1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxide hexafluorophosphate (HATU), O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HBTU), 3-(diethylphosphoryloxy)-1,2,3-benzotriazin-4(3H)-one (DEPBT), O-(6-chlorobenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HCTU), and O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate (TATU).

[0312] Urea-based reagents include O-(5-norbornene-2,3-dicarboximide)-N,N,N',N'-tetramethyluronium tetrafluoroborate (TNTU) and O-(N-succinimidyl)-1,1,3,3-tetramethyluronium tetrafluoroborate (TSTU), O-(3,4-dihydro-4-oxo-1,2,3-benzotriazol-3-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate (TDBTU), O-(1,2-dihydro-2-oxo-1-pyridyl)-N,N,N',N'-tetramethyluronium tetrafluoroborate (TPTU), or O-[(ethoxycarbonyl)cyano-methyleneamino]-N,N,N',N'-tetramethyluronium tetrafluoroborate (TOTU).

[0313] Phosphonium coupling reagents include (7-azabenzotriazol-1-yloxy)tripyrrolidinylphosphonium hexafluorophosphate (PyAOP), benzotriazol-1-yloxy-tris(dimethylamino)phosphonium hexafluorophosphate (BOP), (benzotriazol-1-yloxy)tripyrrolidinylphosphonium hexafluorophosphate (PyBOP), tripyrrolidinylphosphonium bromide hexafluorophosphate (PyBrOP), bis(2-oxo-3-oxazolidinyl)phosphinyl chloride (BOP-Cl), 1-cyano-2-ethoxy-2-oxoethyleneaminooxy-tripyrrolidinyl-phosphonium hexafluorophosphate (PyOxim), and 6-chloro-benzotriazol-1-yloxy-tripyrrolidinylphosphonium hexafluorophosphate (PyClock).

[0314] Anhydride coupling reagents include symmetrical anhydrides, mixed carbonic anhydrides, N-carboxylic anhydrides and carbamate-protected N-carboxylic anhydrides.

[0315] Other reagents include, but are not limited to, 3-(diethylphosphoryloxy)-1,2,3-benzotriazin-4(3H)-one (DEPBT), N,N,N',N'-tetramethylchloroformamidine hexafluorophosphate (TCFH), or propylphosphonic anhydride solution.

[0316] In some embodiments, an amide bond is formed using a carbodiimide coupling reagent in the presence of an additive selected from ethyl cyanohydroxyiminoacetate (Oxyma Pure), 1-hydroxy-7-azabenzotriazole (HOAt), hydroxybenzotriazole (HOBt), 2-hydroxypyridine-N-oxide (HOPO), N-hydroxysuccinimide (HOSu), 5-(hydroxyimino)-1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione (Oxyma B), hexafluoroisopropanol (HFIP), and 4-nitrophenyl alcohol.

[0317] In some embodiments, a base such as a tertiary amine base can be used in the amide bond forming step. Suitable bases include those selected from the group consisting of N-methylmorpholine (NMM), diisopropylethylamine (DIPEA), 1,4-diazabicyclo[2.2.2]octane (DABCO), diethylamine (DEA), triethylamine (TEA), and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU).

[0318] In some embodiments, the coupling is performed in the presence of a solvent selected from acetonitrile (MeCN), methyltetrahydrofuran (MeTHF), dimethyl sulfoxide (DMSO), tetrahydrofuran (THF), water, and 2-propanol.

[0319] In some embodiments, an amide bond is formed using a coupling reagent selected from a carbodiimide coupling reagent and a carbodiimide in the presence of an additive. In some embodiments, an amide bond is formed using N,N'-diisopropylcarbodiimide and 5-(hydroxyamino)-1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione (Oxyma B). In some embodiments, the solvent used in the coupling reaction includes 2-methyltetrahydrofuran.

[0320] In some embodiments, a method for preparing a monocyclic peptide or a salt thereof is provided, the method comprising coupling a monocyclic peptide fragment with a linear peptide fragment, wherein the monocyclic peptide fragment is a peptide of formula (III-A):

[0321] R 1 -X1a-X2a-X3a-X4a-X5a-X6a-X7a-X8a-X9a-R 3

[0322] (III-A);

[0323] wherein each of X1a, X2a and X3a is independently absent or an amino acid residue;

[0324] Each of X4a, X5a, X6a, X7a, X8a and X9a is an amino acid residue;

[0325] R 1 H or C 1-20 Alkanoyl;

[0326] R 3 OH or OP 2 ;and

[0327] The peptide of formula (III-A) cyclizes via a bond between two amino acid residues to form a ring containing 4 to 8 amino acid residues; and

[0328] Wherein the linear peptide fragment has formula (IV-A):

[0329] R 2 -X10a-X11a-X12a-X13a-X14a-X15a-X16a-X17a-X18a-X19a-R 4

[0330] (IV-A);

[0331] wherein each of X10a, X11a, X12a, X13a, X14a and X15a is an amino group

[0332] acid residues;

[0333] Each of X16a, X17a, X18a and X19a is independently absent or an amino group.

[0334] acid residues;

[0335] R 2 is H;

[0336] R 4 For NHP 1 OP 2 , NH2 or OH;

[0337] P 1 is an amino protecting group;

[0338] Each P 2 are independently carboxyl protecting groups;

[0339] And wherein an amide bond is formed between X9a of formula (III-A) and X10a of formula (VI-A).

[0340] In R 3 For OP 2 In the case of carboxyl protecting groups (P 2 ) can be removed in situ during the coupling process.

[0341] In some embodiments, a method for preparing a monocyclic peptide or a pharmaceutically acceptable salt thereof is provided, the method comprising coupling a monocyclic peptide fragment with a linear peptide fragment, wherein the monocyclic peptide fragment is a peptide of formula (III-A):

[0342]

[0343] wherein each of X1a, X2a and X3a is independently absent or an amino acid residue;

[0344] Each of X4a, X5a, X6a, X7a, X8a and X9a is an amino acid residue;

[0345] R 1 H or C 1-20 Alkanoyl;

[0346] R 3 OH or OP 2 ;and

[0347] The peptide of formula (III-A) is cyclized via the bond between X4a and X9a; and

[0348] Wherein the linear peptide fragment has formula (IV-A):

[0349] R 2 -X10a-X11a-X12a-X13a-X14a-X15a-X16a-X17a-X18a-X19a-R 4

[0350] (IV-A);

[0351] wherein each of X10a, X11a, X12a, X13a, X14a and X15a is an amino group

[0352] acid residues;

[0353] Each of X16a, X17a, X18a and X19a is independently absent or an amino group.

[0354] acid residues;

[0355] R 2 is H;

[0356] R 4 For NHP 1 OP 2 , NH2 or OH;

[0357] P 1 is an amino protecting group;

[0358] Each P 2 are independently carboxyl protecting groups;

[0359] And wherein an amide bond is formed between X9a of formula (III-A) and X10a of formula (VI-A).

[0360] In R 3 For OP 2 In the case of carboxyl protecting groups (P 2 ) can be removed in situ during the coupling process.

[0361] In another embodiment, a method for preparing a monocyclic peptide or a pharmaceutically acceptable salt thereof is provided, wherein the monocyclic peptide fragment is a peptide of formula (III-B):

[0362] R 1 -X1a-X2a-X3a-X4a-X5a-X6a-X7a-X8a-X9a-X10a-R 3

[0363] (III-B);

[0364] wherein each of X1a, X2a and X3a is independently absent or an amino acid residue;

[0365] Each of X4a, X5a, X6a, X7a, X8a, X9a and X10a is an amino acid residue;

[0366] R 1 H or C 1-20 Alkanoyl;

[0367] R 3 OH or OP 2 ;and

[0368] The peptide of formula (III-B) cyclizes via a bond between two amino acid residues to form a peptide containing 4 to 8

[0369] amino acid residues; and

[0370] Wherein the linear peptide fragment has formula (IV-B):

[0371] R 2 -X11a-X12a-X13a-X14a-X15a-X16a-X17a-X18a-X19a-R 4

[0372] (IV-B);

[0373] wherein each of X11a, X12a, X13a, X14a and X15a is an amino acid residue;

[0374] Each of X16a, X17a, X18a and X19a is independently absent or an amino group.

[0375] acid residues;

[0376] R 2 is H; and

[0377] R 4 For NHP 1 OP 2 , NH2 or OH;

[0378] P 1 is an amino protecting group;

[0379] Each P 2 are independently carboxyl protecting groups;

[0380] And wherein an amide bond is formed between X10a of formula (III-B) and X11a of formula (VI-B).

[0381] In R 3 For OP 2 In the case of carboxyl protecting groups (P 2 ) can be removed in situ during the coupling process.

[0382] In another embodiment, a method for preparing a monocyclic peptide or a pharmaceutically acceptable salt thereof is provided, wherein the monocyclic peptide fragment is a peptide of formula (III-B):

[0383]

[0384] wherein each of X1a, X2a and X3a is independently absent or an amino acid residue;

[0385] Each of X4a, X5a, X6a, X7a, X8a, X9a and X10a is an amino acid residue;

[0386] R 1 H or C 1-20 Alkanoyl;

[0387] R 3 OH or OP 2 ;and

[0388] The peptide of formula (III-B) is cyclized via the bond between X4a and X9a; and

[0389] Wherein the linear peptide fragment has formula (IV-B):

[0390] R 2-X11a-X12a-X13a-X14a-X15a-X16a-X17a-X18a-X19a-R 4

[0391] (IV-B);

[0392] wherein each of X11a, X12a, X13a, X14a and X15a is an amino acid residue;

[0393] Each of X16a, X17a, X18a and X19a is independently absent or an amino group.

[0394] acid residues;

[0395] R 2 is H; and

[0396] R 4 For NHP 1 OP 2 , NH2 or OH;

[0397] P 1 is an amino protecting group;

[0398] Each P 2 are independently carboxyl protecting groups;

[0399] And wherein an amide bond is formed between X10a of formula (III-B) and X11a of formula (VI-B).

[0400] In R 3 For OP 2 In the case of carboxyl protecting groups (P 2 ) can be removed in situ during the coupling process.

[0401] In another embodiment, a method for preparing a monocyclic peptide or a pharmaceutically acceptable salt thereof is provided, wherein the monocyclic peptide fragment is a peptide of formula (III-C):

[0402] R 1 -X1a-X2a-X3a-X4a-X5a-X6a-X7a-X8a-X9a-X10a-X11a-R 3

[0403] (III-C);

[0404] wherein each of X1a, X2a and X3a is independently absent or an amino acid residue;

[0405] Each of X4a, X5a, X6a, X7a, X8a, X9a, X10a and X11a is

[0406] amino acid residues;

[0407] R 1 H or C 1-20 Alkanoyl;

[0408] R 3 OH or OP 2 ;and

[0409] The peptide of formula (III-C) cyclizes via a bond between two amino acid residues to form a ring containing 4 to 8 amino acid residues; and

[0410] Wherein the linear peptide fragment has formula (IV-C):

[0411] R 2 -X12a-X13a-X14a-X15a-X16a-X17a-X18a-X19a-R 4

[0412] (IV-C);

[0413] wherein each of X12a, X13a, X14a and X15a is an amino acid residue;

[0414] wherein each of X16a, X17a, X18a and X19a is independently absent or

[0415] amino acid residues;

[0416] R 2 is H; and

[0417] R 4 For NHP 1 OP 2 , NH2 or OH;

[0418] P 1 is an amino protecting group;

[0419] Each P 2 are independently carboxyl protecting groups; and

[0420] wherein an amide bond is formed between X11a of formula (III-C) and X12a of formula (IV-C).

[0421] In R 3 For OP 2 In the case of carboxyl protecting groups (P 2 ) can be removed in situ during the coupling process.

[0422] In another embodiment, a method for preparing a monocyclic peptide or a pharmaceutically acceptable salt thereof is provided, wherein the monocyclic peptide fragment is a peptide of formula (III-C):

[0423]

[0424] wherein each of X1a, X2a and X3a is independently absent or an amino acid residue;

[0425] Each of X4a, X5a, X6a, X7a, X8a, X9a, X10a and X11a is

[0426] amino acid residues;

[0427] R 1 H or C 1-20 Alkanoyl;

[0428] R 3 OH or OP 2 ;and

[0429] The peptide of formula (III-C) is cyclized via the bond between X4a and X9a; and

[0430] Wherein the linear peptide fragment has formula (IV-C):

[0431] R 2 -X12a-X13a-X14a-X15a-X16a-X17a-X18a-X19a-R 4

[0432] (IV-C);

[0433] wherein each of X12a, X13a, X14a and X15a is an amino acid residue;

[0434] wherein each of X16a, X17a, X18a and X19a is independently absent or

[0435] amino acid residues;

[0436] R 2 is H; and

[0437] R 4 For NHP 1 OP 2 , NH2 or OH;

[0438] P 1 is an amino protecting group;

[0439] Each P 2 are independently carboxyl protecting groups;

[0440] And wherein an amide bond is formed between X11a of formula (III-C) and X12a of formula (VI-C).

[0441] In R 3 For OP 2 In the case of carboxyl protecting groups (P 2 ) can be removed in situ during the coupling process.

[0442] The functional groups on the side chains of each amino acid selected from X1a to X19a are independently optionally protected with suitable protecting groups.

[0443] P 1 is any suitable amino protecting group. It is readily apparent to those skilled in the art that the protecting group P at the N-terminus of the peptide 1 Should be deprotected before or during the amide bond formation step. In some embodiments, P 1 is an amino protecting group selected from the group consisting of benzyl (Bn), trityl (Trt), 4-methyltrityl (Mtt), β-methoxyethoxytrityl (MEM), 2-nitrophenylsulfonyl (Nps), 2-(4-nitrophenyl)sulfonylethoxycarbonyl (Nsc), benzothiazole-2-sulfonyl (Bts), dithiasuccinyl (Dts), nitrobenzenesulfonyl (Ns), 2-(2-nitrophenyl)propoxycarbonyl (NPPOC), 2-(3,4-methylenedioxy-6-nitrophenyl)propoxycarbonyl (MNPPOC), methylsulfonylethoxycarbonyl (Msc), 9-fluorenylmethyloxycarbonyl (Fmoc), 2,7-di-tert-butyl-Fmoc (Fmoc*), 2-fluoro-Fmoc (Fmoc(2F)), 2-monoisooctyl-Fmoc (mio-Fmoc), benzyloxycarbonyl (Cbz), 2,2,2-tris(2,3-dimethylamino)-1,2-dimethylamino ... chloroethoxycarbonyl (Troc), 2-(trimethylsilyl)ethoxycarbonyl (Teoc), 2-(4-trifluoromethylphenylsulfonyl)ethoxycarbonyl (Tsc), tert-butoxycarbonyl (BOC), 1-adamantyloxycarbonyl (Adoc), 2-adamantyloxycarbonyl (2-Adoc), 2,4-dimethylpentan-3-yloxycarbonyl (Doc), cyclohexyloxycarbonyl (Hoc), 1,1-dimethyl-2,2,2-trichloroethoxycarbonyl (TcBOC), formyl, acetyl (Ac), trifluoroacetyl (TFA), p-toluenesulfonyl (Ts), vinyl, 2-chloroethyl, 2-phenylsulfonylethyl, allyl, 2-nitrobenzyl, 4-nitrobenzyl, diphenyl-4-pyridylmethyl, N',N'-dimethylhydrazine, methoxymethyl, tert-butoxymethyl (Bum), benzyloxymethyl (BOM), 2-tetrahydropyranyl (THP), tris(C 1-4alkyl) silyl (e.g., tri(isopropyl)silyl), 1,1-diethoxymethyl, α,α-dimethyl-3,5-dimethoxybenzyloxycarbonyl (Ddz), 2-(p-biphenyl)-2-propoxycarbonyl (Bpoc), 1,1-dioxonaphtho[1,2-b]thiophene-2-methyloxycarbonyl (α-Nsmoc), 3,3-dioxonaphtho[2,1-b]thiophene-2-methyloxycarbonyl (β-Nsmoc), 1-(4,4-dimethyl-2,6-dioxocyclohexan-1-ylidene)ethyl (Dde), 1-(4,4-dimethyl-2,6-dioxocyclohexan-1-ylidene)ethyl)

[0014] In some embodiments, the present invention may include phenyldithioethoxycarbonyl (ivDde), 2-(phenyl(methyl)sulfonium)ethoxycarbonyl (Pms), N-ethylsulfonylethoxycarbonyl (Esc), 2-(4-sulfophenylsulfonyl)ethoxycarbonyl (Sps), allyloxycarbonyl (Alloc), propargyloxycarbonyl (Poc), 9-(4-bromophenyl)-9-fluorenyl (BrPhF), azidomethoxycarbonyl (Azoc), N-tetrachlorophthaloyl (TCP), phenyldithioethoxycarbonyl (Phdec), 2-pyridyldithioethoxycarbonyl (Pydec), or N-pivaloyloxymethyl (POM).

[0444] P 2 is any suitable carboxyl protecting group. It is readily apparent to those skilled in the art that the protecting group P at the C-terminus of the peptide 2 Should be deprotected before or during the amide bond formation step. In some embodiments, P 2 is a carboxyl protecting group selected from the group consisting of tert-butyl (tBu), methoxy (Ome), ethoxy (Oet), allyl, 1,1-dimethylallyl (Dma), phenylacyl (Pac), p-nitrobenzyl (p-NB), trityl (Tr), 2-chlorotrityl (2-Cl-Trt), 2,4-dimethoxybenzyl (Dmb), 9-fluorenylmethyl (Fm), phenyl, cyclohexyl, benzyl (Bn), 3,4-ethylenedioxy-2-thienyl (EDOT n ), 4-(N-(1-(4,4-dimethyl-2,6-dioxocyclohexylidene)-3-methylbutyl)amino)benzyl (Dmab), trimethylsilylethyl (TMSE), 2-(trimethylsilyl)isopropyl (Tmsi), 2,2,2-trichloroethyl (Tce), carbamoylmethyl (Cam), 4,5-dimethoxy-2-nitrobenzyloxycarbonyl (Dmnb), pentaamminecobalt(III), β-menthyl (Men), β-3-menthylpent-3-yl (Mpe), or 2-phenylisopropyl (2-Ph(iPr)).

[0445] Monocyclic peptide compounds

[0446] The method of the present invention can prepare the monocyclic peptide on a large scale. The deprotected monocyclic peptide can be used as an inhibitor of interleukin-23 receptor (IL-23R).

[0447] The monocyclic peptide is a peptide containing 8 to 21 amino acid residues.

[0448] In some embodiments, the single-cyclic peptide has a relative molecular weight (RMM) greater than 1000.

[0449] In some embodiments, each of the amino acid residues in the compound is independently selected from naturally occurring and non-naturally occurring amino acids, as well as amino acid analogs and amino acid mimetics that function in a manner similar to the naturally occurring amino acids.

[0450] In some embodiments, each amino acid residue is independently selected from Gly, Ala, β-Ala, Leu, Met, Phe, Phe substituted with halo, alkyl, haloalkyl, hydroxy, alkoxy, cyano, cycloalkyl, carboxyl, carboxamido, 2-aminoethoxy or 2-acetamidoethoxy, Trp, Trp substituted with cyano, halo, alkyl, substituted and unsubstituted aryl, haloalkyl, hydroxy, or alkoxy, Lys, Gln, β-homoGln, Pro, V al, Ile, Cys, (D) Cys, α-MeCys, (D) Pen, Pen or Pen (sulfoxide), Cit, Tyr, His, (D) His, Arg, Asn, Glu, Ser, α-MeS er, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, α-MeThr, Lys(Ac), α-MeLys(Ac), α-MeArg, α-MePhe, α-MeTyr Dab(Ac), Dap(Ac), homo-Lys(Ac), Asp, Thr, Sarc, Aib, Dab, Dap, γ-Glu, Gaba, β-Pro, Abu, 1Nal, 2Nal, Lys(b-Ala), Lys(Gly), Lys(benzyl, Ac), Lys(butyl, Ac), Lys(isobutyl, Ac), Lys(propyl, Ac), Lys(PEG2PEG2gEC18OH), Phe(2-Me), Phe(3-Me), Phe(4-Me), Phe(3,4-dimethoxy), 2Quin, 3Quin, 4-amino-4-carboxytetrahydropyran (Gly(THP)), Acvc, cyclohexylAla, 2Pal, 3Pal or 4Pal, 5Pyal. Phe substituted with 2-aminoethoxy is sometimes referred to herein as Tyr(2ea).

[0451] Those skilled in the art will readily recognize that it may be necessary to protect the thiol, amino, carboxyl and hydroxyl groups present on the side chains of amino acid residues. The groups on each of the amino acid residues are optionally protected with a suitable amino acid protecting group.

[0452] In any of the formulae disclosed herein, such as any of Formulae II to XIV, each amino group on the side chain of each amino acid residue is independently substituted with Pg 1 Protection, where each Pg 1 is an amino protecting group independently selected from the group consisting of benzyl (Bn), trityl (Trt), 4-methyltrityl (Mtt), β-methoxyethoxytrityl (MEM), 2-nitrophenylsulfonyl (Nps), 2-(4-nitrophenyl)sulfonylethoxycarbonyl (Nsc), benzothiazole-2-sulfonyl (Bts), dithiasuccinyl (Dts), nitrobenzenesulfonyl (Ns), 2-(2-nitrophenyl)propoxy carbonyl (NPPOC), 2-(3,4-methylenedioxy-6-nitrophenyl) propoxycarbonyl (MNPPOC), methylsulfonylethoxycarbonyl (Msc), 9-fluorenylmethyloxycarbonyl (Fmoc), 2,7-di-tert-butyl-Fmoc (Fmoc*), 2-fluoro-Fmoc (Fmoc(2F)), 2-monoisooctyl-Fmoc (mio-Fmoc), benzyloxycarbonyl (Cbz), 2,2,2 -trichloroethoxycarbonyl (Troc), 2-(trimethylsilyl)ethoxycarbonyl (Teoc), 2-(4-trifluoromethylphenylsulfonyl)ethoxycarbonyl (Tsc), tert-butoxycarbonyl (BOC), 1-adamantyloxycarbonyl (Adoc), 2-adamantyloxycarbonyl (2-Adoc), 2,4-dimethylpentan-3-yloxycarbonyl (Doc), cyclohexyloxycarbonyl (Hoc), 1,1-dimethyl-2, 2,2-trichloroethoxycarbonyl (TcBOC), formyl, acetyl (Ac), trifluoroacetyl (TFA), p-toluenesulfonyl (Ts), vinyl, 2-chloroethyl, 2-phenylsulfonylethyl, allyl, 2-nitrobenzyl, 4-nitrobenzyl, diphenyl-4-pyridylmethyl, N',N'-dimethylhydrazine, methoxymethyl, tert-butoxymethyl (Bum), benzyloxymethyl (BOM), 2-tetrahydropyranyl (THP), tris(C 1-4alkyl) silyl (e.g., tri(isopropyl)silyl), 1,1-diethoxymethyl, α,α-dimethyl-3,5-dimethoxybenzyloxycarbonyl (Ddz), 2-(p-biphenyl)-2-propoxycarbonyl (Bpoc), 1,1-dioxonaphtho[1,2-b]thiophene-2-methyloxycarbonyl (α-Nsmoc), 3,3-dioxonaphtho[2,1-b]thiophene-2-methyloxycarbonyl (β-Nsmoc), 1-(4,4-dimethyl-2,6-dioxocyclohexan-1-ylidene)ethyl (Dde), 1-(4,4-dimethyl-2,6-dioxocyclohexan-1-ylidene)ethyl)

[0014] In some embodiments, the present invention may include phenyldithioethoxycarbonyl (ivDde), 2-(phenyl(methyl)sulfonium)ethoxycarbonyl (Pms), N-ethylsulfonylethoxycarbonyl (Esc), 2-(4-sulfophenylsulfonyl)ethoxycarbonyl (Sps), allyloxycarbonyl (Alloc), propargyloxycarbonyl (Poc), 9-(4-bromophenyl)-9-fluorenyl (BrPhF), azidomethoxycarbonyl (Azoc), N-tetrachlorophthaloyl (TCP), phenyldithioethoxycarbonyl (Phdec), 2-pyridyldithioethoxycarbonyl (Pydec), or N-pivaloyloxymethyl (POM).

[0453] In any of the formulae disclosed herein, such as any of Formulae II to XIV, each carboxyl group on the side chain of each amino acid residue is independently represented by Pg 2 Protection, where each Pg 2 is a carboxyl protecting group independently selected from the following: tert-butyl (tBu), methoxy (Ome), ethoxy (Oet), allyl, 1,1-dimethylallyl (Dma), phenylacyl (Pac), p-nitrobenzyl (p-NB), trityl (Tr), 2-chlorotrityl (2-Cl-Trt), 2,4-dimethoxybenzyl (Dmb), 9-fluorenylmethyl (Fm), phenyl, cyclohexyl, benzyl (Bn), 3,4-ethylenedioxy-2-thienyl (EDOT n ), 4-(N-(1-(4,4-dimethyl-2,6-dioxocyclohexylidene)-3-methylbutyl)amino)benzyl (Dmab), trimethylsilylethyl (TMSE), 2-(trimethylsilyl)isopropyl (Tmsi), 2,2,2-trichloroethyl (Tce), carbamoylmethyl (Cam), 4,5-dimethoxy-2-nitrobenzyloxycarbonyl (Dmnb), hydroxylaminecobalt(III), β-menthyl (Men), β-3-menthylpent-3-yl (Mpe), or 2-phenylisopropyl (2-Ph(iPr));

[0454] In any of the formulae disclosed herein, such as any of Formulae II to XIV, each hydroxyl group on the side chain of each amino acid residue is independently substituted with Pg 3 Protection, where each Pg 3 is a hydroxy protecting group independently selected from the following: benzyl (Bn), cyclohexyl, tert-butyl (tBu), trityl (Trt), tert-butyldimethylsilyl (TBDMS), pseudoproline, tert-butyldiphenylsilyl (TBDPS), 4,5-dimethoxy-2-nitrobenzyloxycarbonyl (Dmnb), propargyloxycarbonyl (Poc).

[0455] In any of the formulae disclosed herein, such as any of Formulae II to XIV, each thiol group on the side chain of each amino acid residue is independently substituted with Pg 4 wherein each thiol protecting group is independently selected from p-methylbenzyl (Meb), p-methoxybenzyl (Mob), trityl (Tr), monomethoxytrityl (Mmt), 2,4,6-trimethoxybenzyl (Tmob), 9-xanthenyl (Xan), 2,2,4,6,7-pentamethyl-5-dihydrobenzofuranylmethyl (Pmbf), benzyl (Bn), tert-butyl (tBu), 1-adamantyl (1-Ada), 9-fluorenylmethyl (Fm), 2-(2,4-dinitrophenyl)ethyl 1-Hydroxy-2-nitro-1-pyridine-5-sulfonyl group ( ...

[0456] In some embodiments, the amino functional group on each of the amino acid side chains is protected with a protecting group independently selected from Fmoc, Cbz, and Boc. In some embodiments, the thiol functional group on each of the amino acid side chains is protected with a protecting group independently selected from Trt and Acm. In some embodiments, the carboxylic acid functional group on each of the amino acid side chains is protected with a protecting group of tert-butyl.

[0457] In some embodiments, the monocyclic peptide is a compound of formula (IIa):

[0458] R 1-X1a-X2a-X3a-X4a-X5a-X6a-X7a-X8a-X9a-X10a-X11a-X12a-X13a-X14a-

[0459] X15a-X16a-X17a-X18a-X19a-R 4

[0460] (IIa)

[0461] in

[0462] R 1 H or C 1-20 Alkanoyl;

[0463] R 4 For NHP 1 or NH2;

[0464] P 1 is any amino protecting group;

[0465] Each of X1a, X2a, X3a, X18a and X19a is independently absent or any amino acid residue;

[0466] X4a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide);

[0467] X5a is Cit, Glu, Gly, substituted Gly, Leu, Ile, β-Ala, Ala, Lys, Asn, Pro, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, Lys(Ac), α-MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), Gln, Asp or Cys;

[0468] X6a is Thr, 2-aminoisobutyric acid, Asp, Dab, Gly, Pro, Ser, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, α-MeThr, α-MeSer, or Val;

[0469] X7a is unsubstituted Trp, or Trp substituted with cyano, halo, alkyl, substituted or unsubstituted aryl, haloalkyl, hydroxyl or alkoxy;

[0470] X8a is Gln, α-Me-Lys, α-MeLeu, α-MeLys(Ac), β-homoGln, Cit, Glu, Phe, Asn, Thr, Val, 2-aminoisobutyric acid, α-MeGln, α-MeAsn, Lys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), 1Nal, 2Nal or Trp;

[0471] X9a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide);

[0472] X10a is unsubstituted Phe, or Phe substituted with halo, alkyl, haloalkyl, hydroxy, alkoxy, carboxyl, carboxamido, 2-aminoethoxy, or 2-acetylaminoethoxy;

[0473] X11a is 2Nal, unsubstituted Trp, or Trp substituted with cyano, halo, alkyl, haloalkyl, hydroxy, alkoxy, Phe(2-Me), Phe(3-Me), Phe(4-Me), Phe(3,4-dimethoxy), or 1Nal;

[0474] X12a is 4-amino-4-carboxytetrahydropyran (Gly(THP)), α-MeLys, α-MeLeu, α-MeArg, α-MePhe, α-MeLeu, α-MeLys, α-MeAsn, α-MeTyr, Ala, cyclohexylAla, Lys, or 2-aminoisobutyric acid;

[0475] X13a is 2-aminoisobutyric acid, Glu, Cit, Gln, Lys(Ac), α-MeArg, α-MeGlu, α-MeLeu, α-MeLys, α-Me-Asn, α-MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), or Lys; or X13a is Lys, pegylated Lys, b-homoGlu, or Lys(Y2-Ac), wherein Y2 is an amino acid residue;

[0476] X14a is Asn, 2Nal, 2-aminoisobutyric acid, Arg, Cit, Asp, Phe, Gly, Lys, Leu, Ala, (D)Ala, β-Ala, His, Thr, n-Leu, Gln , Ser, (D)Ser, Tic, Trp, α-MeGln, α-MeAsn, α-MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac) or Lys(Ac);

[0477] X15a is Ala, β-Ala, Arg, Asn, Asp, Cit, Cys, Glu, Gln, Gly, substituted or unsubstituted His, (D)His, Ile, Lue, (D)Lue, Lys, (D)Lys, Met, 2Pal, 3Pal or 4Pal, Phe, Pro, 5Pyal, 2Quin, 3Quin, Ser, Thr, Trp, Tyr, Val; Leu;

[0478] X16a is absent or is Sarc, aMeLeu, (D)NmeTyr, His, (D)Thr, bAla, Pro, or (D)Pro;

[0479] X17a is absent or is Lys(PEG2PEG2gEC18OH); and wherein the single-ring peptide fragment is cyclized via bonds between amino acids to form a ring containing 4 and 8 amino acid residues.

[0480] In some embodiments, the amino, carboxyl, hydroxyl and thiol groups on the side chains of each of X1a to X19a are independently protected with suitable protecting groups. In some embodiments, each amino group on the side chains of each of X1a to X19a is independently protected with Pg as defined above. 1 Protection; each carboxyl group on the side chain of each of X1a to X19a is independently protected by Pg as defined above 2 Protection; each hydroxyl group on the side chain of each of X1a to X19a is independently protected by Pg as defined above 3 Protection; and each thiol group on the side chain of each of X1a to X19a is independently protected by Pg as defined above 4 Protect.

[0481] In some embodiments, the monocyclic peptide is a compound of formula (II):

[0482] R 1 -X3a-X4a-X5a-X6a-X7a-X8a-X9a-X10a-X11a-X12a-X13a-X14a-X15a-

[0483] X16a-R 4

[0484] (II).

[0485] In some embodiments, the amino, carboxyl, hydroxyl and thiol groups on the side chains of each of X3a to X16a are independently protected with suitable protecting groups. In some embodiments, each amino group on the side chains of each of X3a to X16a is independently protected with Pg as defined above. 1Protection; each carboxyl group on the side chain of each of X3a to X16a is independently protected by Pg as defined above 2 Protection; each hydroxyl group on the side chain of each of X3a to X16a is independently protected by Pg as defined above 3 Protection; and each thiol group on the side chain of each of X3a to X16a is independently protected by Pg as defined above 4 Protect.

[0486] In some embodiments, the single-cyclic peptide is a compound of Formula (Ia), (Ib), (Ic), (Id), or (Ie):

[0487] R 1 -X4a-X5a-X6a-[Trp]-X8a-X9a-[Phe]-[2Nal]-X12a-X13a-X14a-X15a-X16a-R 4

[0488] (Ia),

[0489] R 1 -X4a-X5a-X6a-[Trp]-X8a-X9a-[Phe]-X11a-X12a-X13a-X14a-[Pal]-X16a-R 4

[0490] (Ib),

[0491] R 1 -X4a-X5a-X6a-X7a-X8a-X9a-[Phe]-[2Nal]-X12a-X13a-X14a-[Pal]-X16a-R 4

[0492] (Ic),

[0493] R 1 -X4a-X5a-X6a-[Trp]-X8a-X9a-X10-[2Nal]-X12a-X13a-X14a-[Pal]-X16a-R 4

[0494] (Id); or

[0495] R 1 -X4a-X5a-X6a-[Trp]-X8a-X9a-[Phe]-[2Nal]-X12a-X13a-X14a-[Pal]-X16a-R 4

[0496] (Ie)

[0497] wherein Trp is unsubstituted Trp, or Trp substituted by cyano, halo, alkyl, haloalkyl, alkoxy, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl;

[0498] wherein Phe is unsubstituted Phe, or Phe substituted with halo, alkyl, haloalkyl, hydroxy, alkoxy, cyano, cycloalkyl, carboxyl, carboxamido, 2-aminoethoxy, or 2-acetylaminoethoxy;

[0499] wherein 2Nal is unsubstituted 2Nal;

[0500] Wherein Pal is 2Pal, 3Pal or 4Pal.

[0501] In some embodiments, the monocyclic peptide compound is Ac-(D)Arg-Abu-Gln-Thr-Trp-Gln-Cys-Tyr(2ea)-2Nal-Gly(THP)-Glu-Asn-Asn-NH2 (SEQ ID NO.1); the monocyclic peptide fragment is Ac-(D)Arg-Abu-Gln-Thr-Trp-Gln-Cys-OH (SEQ ID NO.2), and the linear peptide fragment is H-Tyr(2ea)-2Nal-Gly(THP)-Glu-Asn-Asn-NH2.

[0502] In some embodiments, the monocyclic peptide compound has the following structure:

[0503]

[0504] In some embodiments, the single-ring peptide compound is Ac-Pen-Asn-Thr-Trp(7-Me)-Lys(Ac)-Pen-Tyr(2ea)-2Nal-alphaMeLys-Lys(Ac)-Asn-D-Leu-NH2 (SEQ ID NO.3); the single-ring peptide fragment is Ac-Pen-Asn-Thr-Trp(7-Me)-Lys(Ac)-Pen-Tyr(2ea)-OH (SEQ ID NO.4), and the linear peptide fragment is H-2Nal-αMeLys-Lys(Ac)-Asn-D-Leu-NH2.

[0505] In some embodiments, the monocyclic peptide compound has the following structure:

[0506]

[0507] In some embodiments, the monocyclic peptide compound is Ac-Pen-Asn-Thr-Trp(7-Me)-Lys(Ac)-Pen-Tyr(2ea)-2Nal-Gly(THP)-Glu-Asn-3Pal-Sarc-NH 2- (SEQ ID NO.5); the single-cyclic peptide fragment is Ac-Pen-Asn-Thr-Trp(7-Me)-Lys(Ac)-Pen-Tyr(2ea)-OH (SEQ ID NO.4), and the linear peptide fragment is H-2Nal-Gly(THP)-Glu-Asn-3Pal-Sarc-NH2.

[0508] In some embodiments, the monocyclic peptide compound has the following structure:

[0509]

[0510] Protected monocyclic peptide compounds

[0511] In order to obtain the final active pharmaceutical ingredient (API), a final overall deprotection step may be required to remove the protecting groups on the amino acid residues, such as the protecting groups on the side chains of each of the amino acid residues X1a to X19a. In some embodiments, the overall deprotection is performed using acidic conditions.

[0512] In some embodiments, the method for preparing a monocyclic peptide compound involves a deprotection step of a compound of formula (II), wherein the compound of formula (II) is:

[0513]

[0514] in

[0515] R 1 H or C 1-20 Alkanoyl;

[0516] R 4 For NHP 1 ;

[0517] P 1 is an amino protecting group;

[0518] X3a does not exist or is any amino acid residue;

[0519] X4a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide);

[0520] X5a is Cit, Glu, Gly, substituted Gly, Leu, Ile, β-Ala, Ala, Lys,

[0521] Asn, Pro, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, Lys(Ac), α-

[0522] MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), Gln, Asp or Cys;

[0523] X6a is Thr, 2-aminoisobutyric acid, Asp, Dab, Gly, Pro, Ser, α-MeGln,

[0524] α-MeLys, α-MeLeu, α-MeAsn, α-MeThr, α-MeSer or Val;

[0525] X7a is unsubstituted Trp, or is substituted or unsubstituted by cyano, halogen, alkyl, substituted or unsubstituted aromatic

[0526] Trp substituted with alkyl, haloalkyl, hydroxy or alkoxy;

[0527] X8a is Gln, α-Me-Lys, α-MeLeu, α-MeLys(Ac), β-homoGln, Cit,

[0528] Glu, Phe, Asn, Thr, Val, 2-aminoisobutyric acid, α-MeGln, α-MeAsn,

[0529] Lys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), 1Nal, 2Nal or Trp;

[0530] X9a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide);

[0531] X10a is unsubstituted Phe, or Phe substituted with halo, alkyl, haloalkyl, hydroxy, alkoxy, carboxyl, carboxamido, 2-aminoethoxy, or 2-acetylaminoethoxy;

[0532] X11a is 2Nal, unsubstituted Trp, or Trp substituted with cyano, halo, alkyl, haloalkyl, hydroxy, alkoxy, Phe(2-Me), Phe(3-Me), Phe(4-Me), Phe(3,4-dimethoxy), or 1Nal;

[0533] X12a is 4-amino-4-carboxy-tetrahydropyran (Gly(THP)), α-MeLys, α-

[0534] MeLeu, α-MeArg, α-MePhe, α-MeLeu, α-MeLys, α-MeAsn, α-

[0535] MeTyr, Ala or cyclohexylAla, Lys or 2-aminoisobutyric acid;

[0536] X13a is 2-aminoisobutyric acid, Glu, Cit, Gln, Lys(Ac), α-MeArg, α-

[0537] MeGlu, α-MeLeu, α-MeLys, α-Me-Asn, α-MeLys(Ac), Dab(Ac),

[0538] Dap(Ac), homo-Lys(Ac) or Lys; or X13a is Lys, pegylated Lys,

[0539] b-homoGlu or Lys(Y2-Ac), where Y2 is an amino acid residue;

[0540] X14a is Asn, 2Nal, 2-aminoisobutyric acid, Arg, Cit, Asp, Phe, Gly,

[0541] Lys, Leu, Ala, (D)Ala, β-Ala, His, Thr, n-Leu, Gln, Ser, (D)Ser,

[0542] Tic, Trp, α-MeGln, α-MeAsn, α-MeLys(Ac), Dab(Ac), Dap(Ac),

[0543] homo-Lys(Ac) or Lys(Ac);

[0544] X15a is Ala, β-Ala, Arg, Asn, Asp, Cit, Cys, Glu, Gln, Gly, substituted or unsubstituted His, (D)His, Ile, Lue, (D)Lue, Lys, (D)Lys, Met,

[0545] 2Pal, 3Pal or 4Pal, Phe, Pro, 5-Pyal, 2Quin, 3Quin, Ser, Thr, Trp,

[0546] Tyr, Val; Leu;

[0547] X16a does not exist or is Sarc, aMeLeu, (D)NmeTyr, His, (D)Thr, bAla,

[0548] Pro or (D)Pro;

[0549] and the compound is cyclized via the Pen-Pen disulfide bond between X4a and X9a; or

[0550] The compound is cyclized via an Abu-Cys or Abu-Pen thioether bond between X4a and X9a; wherein the side chain of each of the amino acid residues is independently optionally protected by a suitable protecting group.

[0551] In some embodiments, the amino, carboxyl, hydroxyl and thiol groups on the side chains of each of X3a to X19a are independently protected with protecting groups. The amino protecting group can be independently selected from Fmoc, Cbz and Boc. The carboxyl protecting group can be independently selected from methyl, tert-butyl, trityl (Tr), 2,4-dimethoxybenzyl (Dmb), 9-fluorenylmethyl (Fm) and benzyl (Bn). The hydroxyl protecting group can be independently selected from tert-butyl. The thiol protecting group can be independently selected from trityl (Tr) or acetylaminomethyl (Acm).

[0552] In some embodiments, P 1 is Fmoc, Cbz or Boc; and / or R 1 is C(O)CH3; and / or R 4 is NH2.

[0553] In some embodiments, the compound of formula (III) is Ac-Pen-Asn-Thr-Trp(7-Me)-Lys(Ac)-Pen-Tyr(2ea)-OH, wherein the hydroxyl and amino groups on Thr and Tyr(2ea) are protected; and the compound of formula (IV) is H-2Nal-Gly(THP)-Glu-Asn-3Pal-Sarc-NHP 1 , wherein the carboxyl group on Glu is protected; and the compound of formula (II) is Ac-Pen-Asn-Thr-Trp(7-Me)-Lys(Ac)-Pen-Tyr(2ea)-2Nal-Gly(THP)-Glu-Asn-3Pal-Sarc-NHP 1 , wherein the carboxyl and amino groups on each of Thr, Tyr(2ea) and Glu are protected.

[0554] In some embodiments, the compound of formula (II) is deprotected to form a compound of formula (I):

[0555]

[0556] where R 1 H or C 1-20 Alkanoyl;

[0557] R 4 is NH2;

[0558] X3 does not exist or is any amino acid residue;

[0559] X4 is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide);

[0560] X5 is Cit, Glu, Gly, substituted Gly, Leu, Ile, β-Ala, Ala, Lys,

[0561] Asn, Pro, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, Lys(Ac), α-

[0562] MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), Gln, Asp or Cys;

[0563] X6 is Thr, 2-aminoisobutyric acid, Asp, Dab, Gly, Pro, Ser, α-MeGln,

[0564] α-MeLys, α-MeLeu, α-MeAsn, α-MeThr, α-MeSer or Val;

[0565] X7 is unsubstituted Trp, or is replaced by cyano, halogen, alkyl, haloalkyl, hydroxyl or

[0566] Alkoxy-substituted Trp;

[0567] X8 is Gln, α-Me-Lys, α-MeLeu, α-MeLys(Ac), β-homoGln, Cit,

[0568] Glu, Phe, Asn, Thr, Val, 2-aminoisobutyric acid, α-MeGln, α-MeAsn,

[0569] Lys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), 1Nal, 2Nal or Trp;

[0570] X9 is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide);

[0571] X10 is unsubstituted Phe, or Phe substituted with halo, alkyl, haloalkyl, hydroxy, alkoxy, carboxyl, carboxamido, 2-aminoethoxy, or 2-acetylaminoethoxy;

[0572] and

[0573] X11 is 2Nal, unsubstituted Trp, or Trp substituted with cyano, halo, alkyl, haloalkyl, hydroxy, alkoxy, Phe(2-Me), Phe(3-Me), Phe(4-Me), Phe(3,4-dimethoxy), or 1Nal;

[0574] X12 is 4-amino-4-carboxy-tetrahydropyran (Gly(THP)), α-MeLys, α-

[0575] MeLeu, α-MeArg, α-MePhe, α-MeLeu, α-MeLys, α-MeAsn, α-

[0576] MeTyr, Ala, cyclohexylAla, Lys or 2-aminoisobutyric acid;

[0577] X13 is 2-aminoisobutyric acid, Glu, Cit, Gln, Lys(Ac), α-MeArg, α-

[0578] MeGlu, α-MeLeu, α-MeLys, α-Me-Asn, α-MeLys(Ac), Dab(Ac),

[0579] Dap(Ac), homo-Lys(Ac) or Lys; or X13 is Lys, PEGylated Lys, b-

[0580] homoGlu or Lys(Y2-Ac), where Y2 is an amino acid residue;

[0581] X14 is Asn, 2Nal, 2-aminoisobutyric acid, Arg, Cit, Asp, Phe, Gly,

[0582] Lys, Leu, Ala, (D)Ala, β-Ala, His, Thr, n-Leu, Gln, Ser, (D)Ser,

[0583] Tic, Trp, α-MeGln, α-MeAsn, α-MeLys(Ac), Dab(Ac), Dap(Ac),

[0584] homo-Lys(Ac) or Lys(Ac);

[0585] X15 is Ala, β-Ala, Arg, Asn, Asp, Cit, Cys, Glu, Gln, Gly, substituted or unsubstituted His, (D)His, Ile, Lue, (D)Lue, Lys, (D)Lys, Met,

[0586] 2Pal, 3Pal or 4Pal, Phe, Pro, 5-Pyal, 2Quin, 3Quin, Ser, Thr, Trp,

[0587] Tyr, Val, Leu;

[0588] X16 does not exist or is Sarc, aMeLeu, (D)NmeTyr, His, (D)Thr, bAla,

[0589] Pro or (D)Pro;

[0590] And the compound is cyclized via a Pen-Pen disulfide bond between X4 and X9; or the compound is cyclized via an Abu-Cys or Abu-Pen thioether bond between X4 and X9.

[0591] In some embodiments, X4a is (D)Pen, Pen, or Pen(sulfoxide); and X9a is (D)Pen, Pen, or Pen(sulfoxide).

[0592] In some embodiments, the deprotection is performed using an acid. The acid includes acetic acid.

[0593] In some embodiments, the compound of formula (I) is Ac-Pen-Asn-Thr-Trp(7-Me)-Lys(Ac)-Pen-Tyr(2ea)-2Nal-Gly(THP)-Glu-Asn-3Pal-Sarc-NH2. Ac-Pen-Asn-Thr-Trp(7-Me)-Lys(Ac)-Pen-Tyr(2ea)-2-Nal-Gly(THP)-Glu-Asn-3-Pal-Sarc-NH2 has the following structure:

[0594]

[0595] In some embodiments, the protected precursor of the compound of formula (I) (wherein the compound of formula (I) is Ac-Pen-Asn-Thr-Trp(7-Me)-Lys(Ac)-Pen-Tyr(2ea)-2-Nal-Gly(THP)-Glu-Asn-3-Pal-Sarc-NH2) is a compound of formula (II) having the following structure:

[0596]

[0597] Among them Pg 1 、Pg 2 and Pg 3is a protecting group as described above. In some embodiments, Pg 1 For Boc, Pg 2 is tert-butyl, and Pg 3 For Boc.

[0598] linear peptide fragments

[0599] In some embodiments, the linear fragment is a peptide having a relative molecular weight (RMM) between 500 and 3000.

[0600] In some embodiments, the linear peptide fragment is a peptide containing 5 or 6 amino acid residues. In another embodiment, the linear peptide fragment is a peptide containing 6 residues.

[0601] In some embodiments, the linear peptide fragment is an unbranched peptide. An unbranched peptide is a peptide consisting of a chain of amino acid residues that does not include other amino acid residues branching out of the amino acid chain. A peptide consisting of a chain of amino acid residues cyclized by amino acid side chains at the terminal positions is also referred to as unbranched.

[0602] In some embodiments, the linear peptide fragment is a peptide of Formula (IV-A), (IV-B), or (IV-C):

[0603] R 2 -X10a-X11a-X12a-X13a-X14a-X15a-X16a-X17a-X18a-X19a-R 4

[0604] (IV-A);

[0605] R 2 -X11a-X12a-X13a-X14a-X15a-X16a-X17a-X18a-X19a-R 4

[0606] (IV-B);

[0607] R 2 -X12a-X13a-X14a-X15a-X16a-X17a-X18a-X19a-R 4

[0608] (IV-C);

[0609] wherein each of X10a, X11a, X12a, X13a, X14a and X15a is an amino acid residue;

[0610] Each of X16a, X17a, X18a and X19a is independently absent or an amino acid residue;

[0611] R 2 is H;

[0612] R 4 For NHP 1 OP 2 , NH2 or OH;

[0613] P 1 is an amino protecting group; and

[0614] P 2 A carboxyl protecting group.

[0615] In some embodiments, the amino, carboxyl, hydroxyl, and thiol groups on the side chain of each of X10a to X19a are independently protected with a suitable protecting group.

[0616] In some embodiments, the linear fragment is a compound of formula (IV):

[0617] R 2 -X11a-X12a-X13a-X14a-X15a-X16a-R 4

[0618] (IV)

[0619] in

[0620] R 2 is H;

[0621] R 4 For NHP 1 or NH2;

[0622] P 1 is an amino protecting group;

[0623] X11a is 2Nal, unsubstituted Trp or cyano, halogen, alkyl, haloalkyl,

[0624] Trp substituted with hydroxy, alkoxy, Phe(2-Me), Phe(3-Me), Phe(4-Me), Phe(3,4-dimethoxy), or 1Nal;

[0625] X12a is 4-amino-4-carboxy-tetrahydropyran (Gly(THP)), α-MeLys, α-

[0626] MeLeu, α-MeArg, α-MePhe, α-MeLeu, α-MeLys, α-MeAsn, α-

[0627] MeTyr, Ala, cyclohexylAla, Lys or 2-aminoisobutyric acid;

[0628] X13a is 2-aminoisobutyric acid, Glu, Cit, Gln, Lys(Ac), α-MeArg, α-

[0629] MeGlu, α-MeLeu, α-MeLys, α-Me-Asn, α-MeLys(Ac), Dab(Ac),

[0630] Dap(Ac), homo-Lys(Ac) or Lys; or X13a is Lys, pegylated Lys,

[0631] b-homoGlu or Lys(Y2-Ac), where Y2 is an amino acid residue;

[0632] X14a is Asn, 2Nal, 2-aminoisobutyric acid, Arg, Cit, Asp, Phe, Gly,

[0633] Lys, Leu, Ala, (D)Ala, β-Ala, His, Thr, n-Leu, Gln, Ser, (D)Ser,

[0634] Tic, Trp, α-MeGln, α-MeAsn, α-MeLys(Ac), Dab(Ac), Dap(Ac),

[0635] homo-Lys(Ac) or Lys(Ac);

[0636] X15a is Ala, β-Ala, Arg, Asn, Asp, Cit, Cys, Glu, Gln, Gly, substituted or unsubstituted His, (D)His, Ile, Lue, (D)Lue, Lys, (D)Lys, Met,

[0637] 2Pal, 3Pal or 4Pal, Phe, Pro, 5-Pyal, 2Quin, 3Quin, Ser, Thr, Trp,

[0638] Tyr, Val, Leu;

[0639] X16a does not exist or is Sarc, aMeLeu, (D)NmeTyr, His, (D)Thr, bAla,

[0640] Pro or (D)Pro.

[0641] In some embodiments, the amino, carboxyl, hydroxyl, and thiol groups on the side chain of each of X11a to X16a are independently protected with a suitable protecting group.

[0642] In some embodiments, the linear peptide fragment is R 2 -2Nal-Gly(THP)-Glu-Asn-3Pal-Sarc-R 4 .

[0643] In some embodiments, the linear peptide fragment is a compound of formula (IV) having the following structure:

[0644]

[0645] In some embodiments, the linear peptide fragment is prepared by deprotecting a protected precursor of the linear peptide fragment. The protected precursor of the linear peptide fragment is a compound produced by reacting a compound of formula (VII) with a compound of formula (VIII), wherein R 4 For NHP 1 In some embodiments, the protected precursor of the linear peptide fragment is a compound having the following structure:

[0646]

[0647] Preparation of linear peptide fragments

[0648] The method for preparing a monocyclic peptide may further comprise the step of preparing a linear peptide fragment. The preparation of the linear peptide fragment is a convergent synthesis method that can be performed in solution phase without the use of a solid support.

[0649] In some embodiments, the linear peptide fragment is a compound of formula (IV) which can be prepared by treating a compound of formula (VII) with

[0650] R 6 -X11a-X12a-R 3

[0651] (VII)

[0652] and a compound of formula (VIII)

[0653] R 2 -X13a-X14a-X15a-X16a-R 4

[0654] (VIII)

[0655] The reaction results in the formation of an amide bond between X12a and X13a;

[0656] in

[0657] R 2 is H;

[0658] R 3 OH or OP 2;

[0659] R 4 NH2 or NHP 1 ;

[0660] R 6 H or P 1 ;

[0661] Each P 1 is an amino protecting group; and

[0662] Each P 2 is independently a carboxyl protecting group.

[0663] In R 3 For OP 2 In the case of carboxyl protecting groups (P 2 ) can be removed in situ during the coupling process.

[0664] In some embodiments, amide bonds are formed using a carbodiimide coupling reagent, optionally in the presence of an additive.

[0665] In some embodiments, the amide bond is formed in the presence of N-ethyl-N'-dimethylaminopropylcarbodiimide (EDCI) and 1-hydroxy-7-azabenzotriazole (HOAt).

[0666] In some embodiments, R 4 is NH2; and / or R 6 P 1 And P 1 It is Fmoc.

[0667] In some embodiments, when R 6 P 1 When the compound of formula (VII) is reacted with the compound of formula (VIII) to obtain a protected precursor of the compound of formula (IV). The terminal amino group is deprotected to remove P 1 , to obtain the compound of formula (IV).

[0668] In some embodiments, the method for preparing a linear peptide fragment further comprises preparing a compound of formula (VII), comprising: 6 -X11a-R 3 Compounds with R 2 -X12a-R 5 to form an amide bond between X11a and X12a, wherein R 2 H, R 3 OH, R 5 OH or OP 2 , R 6 P 1, P 1 is an amino protecting group, and P 2 A carboxyl protecting group.

[0669] In some embodiments of the compound of Formula (VII):

[0670] R 3 OH or OP 2 ;

[0671] R 6 H or P 1 ;

[0672] P 1 is an amino protecting group; and

[0673] P 2 is a carboxyl protecting group;

[0674] X11a is 2Nal, unsubstituted Trp, or Trp substituted with cyano, halo, alkyl, haloalkyl, hydroxy, alkoxy, Phe(2-Me), Phe(3-Me), Phe(4-Me), Phe(3,4-dimethoxy), or 1Nal;

[0675] X12a is 4-amino-4-carboxy-tetrahydropyran (Gly(THP)), α-MeLys, α-

[0676] MeLeu, α-MeArg, α-MePhe, α-MeLeu, α-MeLys, α-MeAsn, α-

[0677] MeTyr, Ala, cyclohexylAla, Lys or 2-aminoisobutyric acid.

[0678] In some embodiments, the amino, carboxyl, hydroxyl, and thiol groups on the side chain of each of X11a to X12a are independently protected with a suitable protecting group.

[0679] In some embodiments, the compound of formula (VII) is R 6 -2Nal-Gly(THP)-R 3 .

[0680] In some embodiments, the compound of formula (VII) has the following structure:

[0681]

[0682] In some embodiments of the compound of Formula (VIII):

[0683] R 2 is H;

[0684] R 5 NH2 or NHP 1 ;

[0685] P 1 is an amino protecting group;

[0686] X13a is 2-aminoisobutyric acid, Glu, Cit, Gln, Lys(Ac), α-MeArg, α-

[0687] MeGlu, α-MeLeu, α-MeLys, α-Me-Asn, α-MeLys(Ac), Dab(Ac),

[0688] Dap(Ac), homo-Lys(Ac) or Lys; or X13a is Lys, pegylated Lys,

[0689] b-homoGlu or Lys(Y2-Ac), where Y2 is an amino acid residue;

[0690] X14a is Asn, 2Nal, 2-aminoisobutyric acid, Arg, Cit, Asp, Phe, Gly,

[0691] Lys, Leu, Ala, (D)Ala, β-Ala, His, Thr, n-Leu, Gln, Ser, (D)Ser,

[0692] Tic, Trp, α-MeGln, α-MeAsn, α-MeLys(Ac), Dab(Ac), Dap(Ac),

[0693] homo-Lys(Ac) or Lys(Ac);

[0694] X15a is Ala, β-Ala, Arg, Asn, Asp, Cit, Cys, Glu, Gln, Gly, substituted or unsubstituted His, (D)His, Ile, Lue, (D)Lue, Lys, (D)Lys, Met,

[0695] 2Pal, 3Pal or 4Pal, Phe, Pro, 5-Pyal, 2Quin, 3Quin, Ser, Thr, Trp,

[0696] Tyr, Val, Leu;

[0697] X16a does not exist or is Sarc, aMeLeu, (D)NmeTyr, His, (D)Thr, bAla,

[0698] Pro or (D)Pro.

[0699] In some embodiments, the amino, carboxyl, hydroxyl, and thiol groups on the side chain of each of X13a to X16a are independently protected with a suitable protecting group.

[0700] In some embodiments, the compound of formula (VIII) is R 2 -Glu-Asn-3Pal-Sarc-R 5 .

[0701] In some embodiments, the compound of formula (VIII) has the following structure:

[0702]

[0703] In some embodiments, the compound of formula (VIII) is prepared by deprotecting a protected precursor of the compound of formula (VIII). In some embodiments, the protected precursor of the compound of formula (VIII) has the following structure:

[0704]

[0705] Preparation of compounds of formula (VIII)

[0706] The process for preparing the compound of formula (IV) may further comprise the step of preparing the compound of formula (VIII).

[0707] In some embodiments, the method of preparing a compound of formula (VIII) comprises making a compound of formula (XIII)

[0708] R 2 -X15a-X16a-R 4

[0709] (XIII)

[0710] With a compound of formula (XIV):

[0711] R 6 -X13a-X14a-R 3

[0712] (XIV)

[0713] reacts to form an amide bond between X14a and X15a; wherein

[0714] R 2 is H;

[0715] R 3 OH or OP 2 ;

[0716] R 4 NH2 or NHP1 ;

[0717] R 6 H or P 1 ;

[0718] P 1 is an amino protecting group, and P 2 A carboxyl protecting group.

[0719] In R 3 For OP 2 In the case of carboxyl protecting groups (P 2 ) can be removed in situ during the coupling process.

[0720] In some embodiments, amide bonds are formed using a carbodiimide coupling reagent, optionally in the presence of an additive.

[0721] In some embodiments, the amide bond is formed in the presence of N-ethyl-N'-dimethylaminopropylcarbodiimide (EDCI), 1-hydroxy-7-azabenzotriazole (HOAt), and 1,4-diazabicyclo[2.2.2]octane (DABCO).

[0722] In some embodiments, R 4 is NH2; and / or R 6 P 1 And P 1 For Cbz.

[0723] In some embodiments, when R 6 P 1 When the compound of formula (XIII) is reacted with the compound of formula (XIV) to obtain a protected precursor of the compound of formula (VIII). The terminal amino group is deprotected to remove P 1 , to obtain the compound of formula (VIII).

[0724] In some embodiments, by making the formula R 6 -X15a-R 3 Compounds with R 2 -X16a-R 5 The compound of formula (XIII) is prepared by reacting a compound of formula (X15a) with a hydroxyl group to form an amide bond between X15a and X16a. The amide bond can be formed in the presence of 1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxide hexafluorophosphate (HATU) and N-methyl-2-pyrrolidone (NMP).

[0725] In some embodiments, by making the formula R 6 -X13a-R 3 Compounds with R2 -X14a-R 5 to form an amide bond between X13a and X14a to prepare a compound of formula (XIV); wherein R 2 H, R 3 OH, R 5 OH or OP 2 , and R 6 H or P 1 , where P 1 is an amino protecting group and P 2 In some embodiments, the amide bond is formed in the presence of pivaloyl chloride.

[0726] In some embodiments of the compound of Formula (XIII):

[0727] R 2 is H;

[0728] R 4 For NHP 1 or NH2;

[0729] P 1 is an amino protecting group;

[0730] X15a is Ala, β-Ala, Arg, Asn, Asp, Cit, Cys, Glu, Gln, Gly, substituted or unsubstituted His, (D)His, Ile, Lue, (D)Lue, Lys, (D)Lys, Met,

[0731] 2Pal, 3Pal or 4Pal, Phe, Pro, 5Pyal, 2Quin, 3Quin, Ser, Thr, Trp,

[0732] Tyr, Val; Leu;

[0733] X16a does not exist or is Sarc, aMeLeu, (D)NmeTyr, His, (D)Thr, bAla,

[0734] Pro or (D)Pro.

[0735] In some embodiments, the amino, carboxyl, hydroxyl, and thiol groups on the side chain of each of X15a to X16a are independently protected with a suitable protecting group.

[0736] In some embodiments, the compound of formula (XIII) is R 2 -3Pal-Sarc-R 4 .

[0737] In some embodiments, the compound of formula (XIII) has the following structure:

[0738]

[0739] In some embodiments of the compound of Formula (XIV):

[0740] R 3 OH or OP 2 ;

[0741] R 6 H or P 1 ;

[0742] P 1 is an amino protecting group;

[0743] P 2 is a carboxyl protecting group;

[0744] X13a is 2-aminoisobutyric acid, Glu, Cit, Gln, Lys(Ac), α-MeArg, α-

[0745] MeGlu, α-MeLeu, α-MeLys, α-Me-Asn, α-MeLys(Ac), Dab(Ac),

[0746] Dap(Ac), homo-Lys(Ac) or Lys; or X13a is Lys, pegylated Lys,

[0747] b-homoGlu or Lys(Y2-Ac), where Y2 is an amino acid residue;

[0748] X14a is Asn, 2Nal, 2-aminoisobutyric acid, Arg, Cit, Asp, Phe, Gly,

[0749] Lys, Leu, Ala, (D)Ala, β-Ala, His, Thr, n-Leu, Gln, Ser, (D)Ser,

[0750] Tic, Trp, α-MeGln, α-MeAsn, α-MeLys(Ac), Dab(Ac), Dap(Ac),

[0751] homo-Lys(Ac) or Lys(Ac).

[0752] In some embodiments, the amino, carboxyl, hydroxyl, and thiol groups on the side chain of each of X13a to X14a are independently protected with a suitable protecting group.

[0753] In some embodiments, the compound of formula (XIV) is R 6 -Glu-Asn-R 3 .

[0754] In some embodiments, the compound of formula (XIV) has the following structure:

[0755]

[0756] Single-ring peptide fragment

[0757] In some embodiments, the single-ring peptide fragment is a peptide having a relative molecular weight (RMM) between 500 and 3500.

[0758] In some embodiments, a single-cyclic peptide fragment comprises a ring cyclized by a bond between the side chains of two amino acid residues.

[0759] In some embodiments, the single-cyclic peptide fragment comprises a ring cyclized via a disulfide bridge or thioether bond between the side chains of two amino acid residues.

[0760] In some embodiments, the single-cyclic peptide fragment comprises a loop containing 6 amino acid residues.

[0761] In some embodiments, the single-ring peptide fragment is a peptide containing 7 amino acid residues.

[0762] In some embodiments, a single-ring peptide fragment is a peptide containing 7 amino acid residues, wherein 6 of these amino acid residues form a ring.

[0763] In some embodiments, the single-cyclic peptide fragment comprises a loop that is cyclized by a bond between the side chain of the N-terminal amino acid residue and the side chain of the amino acid residue adjacent to the C-terminal amino acid residue.

[0764] In some embodiments, a monocyclic peptide fragment is prepared by the step of cyclizing a second linear peptide fragment, wherein the second linear peptide fragment is a peptide containing 4 to 11 amino acid residues. In some embodiments, the step of cyclizing the second linear peptide fragment includes forming a bond between the side chains of two amino acid residues. In some embodiments, the step of cyclizing the second linear peptide fragment includes forming a bond between the side chain of the N-terminal amino acid residue and the side chain of the amino acid residue adjacent to the C-terminal amino acid residue. In some embodiments, the step of cyclizing the second linear peptide fragment includes forming a disulfide bridge or a thioether bond between the side chains of the two amino acid residues. In some embodiments, the disulfide bridge is formed in the presence of an oxidant. In some embodiments, the disulfide bridge is formed in the presence of formic acid. In some embodiments, the disulfide bridge is formed in the presence of formic acid and diiodine. Alternative reagents for forming disulfide bonds include thallium (III) trifluoroacetate, or trans-[Pt(en)2Cl2]2+ .

[0765] In some embodiments, the single-cyclic peptide fragment is a peptide of formula (III-A), (III-B), or (III-C):

[0766] R 1 -X1a-X2a-X3a-X4a-X5a-X6a-X7a-X8a-X9a-R 3

[0767] (III-A);

[0768] R 1 -X1a-X2a-X3a-X4a-X5a-X6a-X7a-X8a-X9a-X10a-R 3

[0769] (III-B);

[0770] R 1 -X1a-X2a-X3a-X4a-X5a-X6a-X7a-X8a-X9a-X10a-X11a-R 3

[0771] (III-C);

[0772] wherein each of X1a, X2a and X3a is independently absent or an amino acid residue;

[0773] Each of X4a, X5a, X6a, X7a, X8a, X9a, X10a and X11a is

[0774] amino acid residues;

[0775] R 1 H or C 1-20 Alkanoyl;

[0776] R 3 OH or OP 2 ;

[0777] P 2 A carboxyl protecting group.

[0778] In some embodiments, the peptide of each of Formula (III-A), (III-B), or (III-C) is cyclized via the bond between X4a and X9a.

[0779] In some embodiments, the amino, carboxyl, hydroxyl, and thiol groups on the side chain of each of X1a to X11a are independently protected with a suitable protecting group.

[0780] In some embodiments, the single-ring peptide fragment comprises a loop to which is appended at least one peptide chain comprising at least one amino acid residue. For example, the single-ring peptide fragment may comprise seven amino acid residues, six of which comprise the loop and one of which is appended to the loop.

[0781] In some embodiments, the single-cyclic peptide fragment is a compound of formula (III):

[0782]

[0783] in

[0784] R 1 H or C 1-20 Alkanoyl;

[0785] R 3 OH or OP 2 ;

[0786] P 2 is a carboxyl protecting group;

[0787] X3a does not exist or is any amino acid residue;

[0788] X4a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide);

[0789] X5a is Cit, Glu, Gly, substituted Gly, Leu, Ile, β-Ala, Ala, Lys,

[0790] Asn, Pro, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, Lys(Ac), α-

[0791] MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), Gln, Asp or Cys;

[0792] X6a is Thr, 2-aminoisobutyric acid, Asp, Dab, Gly, Pro, Ser, α-MeGln,

[0793] α-MeLys, α-MeLeu, α-MeAsn, α-MeThr, α-MeSer or Val;

[0794] X7a is unsubstituted Trp, or is substituted or unsubstituted by cyano, halogen, alkyl, substituted or unsubstituted aromatic

[0795] Trp substituted with alkyl, haloalkyl, hydroxy or alkoxy;

[0796] X8a is Gln, α-Me-Lys, α-MeLeu, α-MeLys(Ac), β-homoGln, Cit,

[0797] Glu, Phe, Asn, Thr, Val, 2-aminoisobutyric acid, α-MeGln, α-MeAsn,

[0798] Lys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), 1Nal, 2Nal or Trp;

[0799] X9a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide);

[0800] X10a is unsubstituted Phe, or Phe substituted with halo, alkyl, haloalkyl, hydroxy, alkoxy, carboxyl, carboxamido, 2-aminoethoxy, or 2-acetylaminoethoxy; and

[0801] The compound is cyclized via a Pen-Pen disulfide bond between X4a and X9a; or the compound is cyclized via an Abu-Cys or Abu-Pen thioether bond between X4a and X9a.

[0802] In some embodiments, the amino, carboxyl, hydroxyl, and thiol groups on the side chain of each of X3a to X10a are independently protected with a suitable protecting group.

[0803] In some embodiments, R 1 It is -C(O)CH3.

[0804] In some embodiments, the compound of formula (III) is R 1 -Pen-Asn-Thr-Trp(7-Me)-Lys(Ac)-Pen-Tyr(2ea)-R 3 .

[0805] In some embodiments, the compound of formula (III) has the following structure:

[0806]

[0807] Preparation of single-ring peptide fragments

[0808] The method for preparing a monocyclic peptide may further comprise the step of preparing a monocyclic peptide fragment. The method for preparing a monocyclic peptide fragment may comprise the step of cyclizing a second linear peptide fragment to form a monocyclic peptide fragment, wherein the second linear peptide fragment is a peptide containing 4 to 11 amino acid residues.

[0809] In some embodiments, the step of cyclizing the second linear peptide fragment comprises forming a bond between the side chains of two amino acid residues.

[0810] In some embodiments, the step of cyclizing the second linear peptide fragment comprises forming a bond between the side chain of the N-terminal amino acid residue and the side chain of an amino acid residue adjacent to the C-terminal amino acid residue.

[0811] In some embodiments, the step of cyclizing the second linear peptide fragment comprises forming a disulfide bridge or thioether bond between the side chains of the two amino acid residues. The disulfide bridge is formed using any suitable disulfide bond forming reaction. The thioether bond is formed using any suitable thioether bond forming reaction.

[0812] In some embodiments, the disulfide bridges are formed in the presence of an oxidizing agent. In some embodiments, the disulfide bridges are formed in the presence of formic acid.

[0813] In some embodiments, the disulfide bridge is formed in the presence of diiodide.

[0814] In some embodiments, the method for preparing a monocyclic peptide fragment comprises cyclizing a compound of formula (III'):

[0815] R 1 -X3a-X4a-X5a-X6a-X7a-X8a-X9a-X10a-R 5

[0816] (III')

[0817] To form a Pen-Pen disulfide bond between X4a and X9a,

[0818] R 1 H or C 1-20 Alkanoyl;

[0819] R 5 OH or OP 2 ; and P 2 A carboxyl protecting group.

[0820] In some embodiments, the amino, carboxyl, hydroxyl, and thiol groups on the side chain of each of X3a to X10a are independently protected with a suitable protecting group.

[0821] In some embodiments, the thiol groups on X4a and X9a are deprotected prior to or during cyclization of the compound of formula (III').

[0822] In some embodiments, the Pen-Pen disulfide bond is formed in the presence of an oxidant. In some embodiments, the Pen-Pen disulfide bond is formed in the presence of formic acid. In some embodiments, when the thiol groups on X4a and X9a are protected with a protecting group independently selected from acetamidomethyl (Acm) and trityl (Tr), the Pen-Pen disulfide bond is formed in the presence of diiodine and formic acid.

[0823] In some embodiments, P 2 is CH3 or C(CH3)3; and / or R 1 is C(O)CH3; and / or R 5 For OH.

[0824] In some embodiments, R 5 For OP 2 In R 5 For OP 2 In the case of carboxyl protecting groups (P 2 ) can be removed after the cyclization reaction.

[0825] The second linear peptide fragment

[0826] The monocyclic peptide fragment comprises a ring cyclized by a bond between the side chains of two amino acid residues. The monocyclic peptide fragment is prepared by cyclizing a second linear peptide fragment. The second linear peptide fragment is a peptide of formula (III'), formula (III-A'), formula (III-B') or formula (III-C').

[0827] In some embodiments, the second linear peptide fragment is a peptide of formula (III-A'):

[0828] R 1 -X1a-X2a-X3a-X4a-X5a-X6a-X7a-X8a-X9a-R 5

[0829] (III-A');

[0830] wherein X1a to X9a are as described above for the single-ring peptide fragment, and R 1 H or C 1-20 Alkanoyl, and R 5 OH or OP 2 .

[0831] In some embodiments, the amino, carboxyl, hydroxyl, and thiol groups on the side chains of each of X1a to X9a are independently protected with suitable protecting groups.

[0832] In R 5 For OP 2 In the case of carboxyl protecting groups (P2 ) can be removed after the cyclization reaction.

[0833] In some embodiments, the second linear peptide fragment is a peptide of formula (III-B'):

[0834] R 1 -X1a-X2a-X3a-X4a-X5a-X6a-X7a-X8a-X9a-X10a-R 5

[0835] (III-B');

[0836] wherein X1a to X10a are as described above for the single-ring peptide fragment, and R 1 H or C 1-20 Alkanoyl, and R 5 OH or OP 2 .

[0837] In some embodiments, the amino, carboxyl, hydroxyl, and thiol groups on the side chains of each of X1a to X10a are independently protected with suitable protecting groups.

[0838] In R 5 For OP 2 In the case of carboxyl protecting groups (P 2 ) can be removed after the cyclization reaction.

[0839] In some embodiments, the second linear peptide fragment is a peptide of formula (III-C'):

[0840] R 1 -X1a-X2a-X3a-X4a-X5a-X6a-X7a-X8a-X9a-X10a-X11a-R 5

[0841] (III-C');

[0842] wherein X1a to X10a are as described above for the single-ring peptide fragment, R 1 H or C 1-20 Alkanoyl, and R 5 OH or OP 2 .

[0843] In some embodiments, the amino, carboxyl, hydroxyl, and thiol groups on the side chain of each of X1a to X11a are independently protected with a suitable protecting group.

[0844] In R 5 For OP 2 In the case of carboxyl protecting groups (P 2 ) can be removed after the cyclization reaction.

[0845] In some embodiments, R 1 It is -C(O)CH3.

[0846] In some embodiments, the second linear peptide fragment is a peptide of formula (III'):

[0847] R 1 -X3a-X4a-X5a-X6a-X7a-X8a-X9a-X10a-R 5

[0848] (III')

[0849] in

[0850] R 1 H or C 1-20 Alkanoyl;

[0851] R 5 OH or OP 2 ;

[0852] P 2 is a carboxyl protecting group;

[0853] X3a does not exist or is any amino acid residue;

[0854] X4a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide);

[0855] X5a is Cit, Glu, Gly, substituted Gly, Leu, Ile, β-Ala, Ala, Lys,

[0856] Asn, Pro, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, Lys(Ac), α-

[0857] MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), Gln, Asp or Cys;

[0858] X6a is Thr, 2-aminoisobutyric acid, Asp, Dab, Gly, Pro, Ser, α-MeGln,

[0859] α-MeLys, α-MeLeu, α-MeAsn, α-MeThr, α-MeSer or Val;

[0860] X7a is unsubstituted Trp, or is substituted or unsubstituted by cyano, halogen, alkyl, substituted or unsubstituted aromatic

[0861] Trp substituted with alkyl, haloalkyl, hydroxy or alkoxy;

[0862] X8a is Gln, α-Me-Lys, α-MeLeu, α-MeLys(Ac), β-homoGln, Cit,

[0863] Glu, Phe, Asn, Thr, Val, 2-aminoisobutyric acid, α-MeGln, α-MeAsn,

[0864] Lys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), 1Nal, 2Nal or Trp;

[0865] X9a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide);

[0866] X10a is unsubstituted Phe, or Phe substituted with halo, alkyl, haloalkyl, hydroxy, alkoxy, carboxyl, carboxamido, 2-aminoethoxy, or 2-acetylaminoethoxy.

[0867] In some embodiments, the amino, carboxyl, hydroxyl, and thiol groups on the side chain of each of X3a to X10a are independently protected with a suitable protecting group.

[0868] In some embodiments where the second linear peptide segment is a peptide of formula (III'), R 1 is C(O)CH3, and R 5 For OH.

[0869] In R 5 For OP 2 In the case of carboxyl protecting groups (P 2 ) can be removed after the cyclization reaction.

[0870] In some embodiments, the second linear peptide segment is R 1 -Pen-Asn-Thr-Trp(7-Me)-Lys(Ac)-Pen-Tyr(2ea)-R 5 .

[0871] In some embodiments, the second linear peptide fragment is a compound having the structure:

[0872]

[0873] In some embodiments, the compound of formula (III') is prepared by deprotecting a protected precursor of the compound of formula (III'). In some embodiments, the protected precursor of the compound of formula (III') has the following structure:

[0874]

[0875] Preparation of the second linear peptide fragment (Formula III')

[0876] A second linear peptide fragment is prepared by coupling two smaller peptide fragments.

[0877] The method for preparing a single-cyclic peptide fragment may further comprise the step of preparing a second linear peptide fragment.

[0878] In some embodiments, the second linear peptide fragment is a peptide of formula (III'), and the step of preparing the compound comprises making a compound of formula (V)

[0879] R 1 -X3a-X4a-X5a-X6a-R 3

[0880] (V)

[0881] and a compound of formula (VI)

[0882] R 2 -X7a-X8a-X9a-X10a-R 5

[0883] (VI)

[0884] reacting to form an amide bond between X6a and X7a;

[0885] in

[0886] R 1 H or C 1-20 Alkanoyl;

[0887] R 2 is H;

[0888] R 3 OH or OP 2 ;

[0889] R 5 OH or OP 2 ; and each P 2 is independently a carboxyl protecting group.

[0890] In R 3 For OP 2 In the case of carboxyl protecting groups (P 2 ) can be removed in situ during the coupling process.

[0891] In some embodiments, the amide bond is formed using a carbodiimide coupling reagent, optionally in the presence of an additive. In some embodiments, the carbodiimide is 5-(hydroxyamino)-1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione (Oxyma B).

[0892] In an embodiment, the amide bond is formed in the solvent 2-methyltetrahydrofuran (2-MeTHF).

[0893] In some embodiments, the amide bond is formed in the presence of N,N'-diisopropylcarbodiimide (DIC) and 5-(hydroxyamino)-1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione (Oxyma B).

[0894] In some embodiments, the amide bond is formed in solution phase at a temperature between 5°C and 25°C.

[0895] In some embodiments, R 1 is C(O)CH3; and / or R 5 For OP 2 ; and / or P 2 C 1-6 Alkyl; and / or P 2 For CH3.

[0896] In some embodiments, when R 5 For OP 2 When the compound of formula (V) is reacted with the compound of formula (VI) to obtain a protected precursor of the compound of formula (III'). The terminal carboxyl group is deprotected to remove P 2 , to obtain a compound of formula (III').

[0897] In some embodiments of the compound of Formula (V):

[0898] R 1 H or C 1-20 Alkanoyl;

[0899] R 3 OH or OP 2 ;

[0900] P 2 is a carboxyl protecting group;

[0901] X3a does not exist or is any amino acid residue;

[0902] X4a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide);

[0903] X5a is Cit, Glu, Gly, substituted Gly, Leu, Ile, β-Ala, Ala, Lys,

[0904] Asn, Pro, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, Lys(Ac), α-

[0905] MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), Gln, Asp or Cys;

[0906] X6a is Thr, 2-aminoisobutyric acid, Asp, Dab, Gly, Pro, Ser, α-MeGln,

[0907] α-MeLys, α-MeLeu, α-MeAsn, α-MeThr, α-MeSer or Val.

[0908] In some embodiments, the amino, carboxyl, hydroxyl, and thiol groups on the side chain of each of X3a to X6a are independently protected with a suitable protecting group.

[0909] In some embodiments of the compound of Formula (V), R 1 It is C(O)CH3.

[0910] In some embodiments, the compound of formula (V) is R 1 -Pen-Asn-Thr-R 3 .

[0911] In some embodiments, the compound of Formula (V) is a compound having the following structure:

[0912]

[0913] In some embodiments, the compound of formula (V) is prepared by deprotecting a protected precursor of the compound of formula (V). In some embodiments, the protected precursor of the compound of formula (V) has the following structure:

[0914]

[0915] In some embodiments of the compound of Formula (VI):

[0916] R 2 is H;

[0917] R 5 NH2 or NHP 1 ;

[0918] P 1 is an amino protecting group;

[0919] X7a is unsubstituted Trp, or is substituted or unsubstituted by cyano, halogen, alkyl, substituted or unsubstituted aromatic

[0920] Trp substituted with alkyl, haloalkyl, hydroxy or alkoxy;

[0921] X8a is Gln, α-Me-Lys, α-MeLeu, α-MeLys(Ac), β-homoGln, Cit,

[0922] Glu, Phe, Asn, Thr, Val, 2-aminoisobutyric acid, α-MeGln, α-MeAsn,

[0923] Lys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), 1Nal, 2Nal or Trp;

[0924] X9a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide);

[0925] X10a is unsubstituted Phe, or Phe substituted with halo, alkyl, haloalkyl, hydroxy, alkoxy, carboxyl, carboxamido, 2-aminoethoxy, or 2-acetylaminoethoxy.

[0926] In some embodiments, the amino, carboxyl, hydroxyl, and thiol groups on the side chain of each of X7a to X10a are independently protected with a suitable protecting group.

[0927] In some embodiments, the compound of formula (VI) is R 2 -Trp(7-Me)-Lys(Ac)-Pen-Tyr(2ea)-R 5 .

[0928] In some embodiments, the compound of formula (VI) is a compound having the following structure:

[0929]

[0930] In some embodiments, the protected precursor of the compound of formula (VI) is a compound having the following structure:

[0931]

[0932] Preparation of compounds of formula (V)

[0933] The method for preparing a single-cyclic peptide fragment may include the step of preparing a second linear peptide fragment, and may further include the step of preparing a compound of formula (V).

[0934] In some embodiments, the step of preparing the compound of formula (III) further comprises reacting a compound of formula (V'):

[0935] R 7 -X3a-X4a-X5a-X6a-R 5

[0936] (V')

[0937] Converted to a compound of formula (V):

[0938] R 1 -X3a-X4a-X5a-X6a-R 3

[0939] (V)

[0940] in

[0941] R 1 H or C 1-20 Alkanoyl;

[0942] R 3 OH or OP 2 ;

[0943] R 5 OH or OP 2 ;and

[0944] R 7 H or P 1 ;

[0945] P 1 is an amino protecting group, and each P 2 is independently a carboxyl protecting group.

[0946] In some embodiments, R 7 is Fmoc, and / or R 1 It is C(O)CH3.

[0947] In some embodiments, converting the compound of formula (V') to the compound of formula (V) comprises (i) deprotecting the terminal amino group of the compound of formula (V') to form a compound having the formula H-X3a-X4a-X5a-X6a-R 3 The compound of formula H-X3a-X4a-X5a-X6a-R 3 The compound of formula (V') is contacted with acetic anhydride to form a compound of formula (V').

[0948] In some embodiments, the method of preparing a compound of formula (V) from formula (V') may further comprise the step of preparing a compound of formula (V').

[0949] In some embodiments of the compound of Formula (V'):

[0950] R 5 OH or OP 2 ;

[0951] R 7 H or P 1 ;

[0952] P 1 is an amino protecting group;

[0953] P 2 is a carboxyl protecting group;

[0954] X3a does not exist or is any amino acid residue;

[0955] X4a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide);

[0956] X5a is Cit, Glu, Gly, substituted Gly, Leu, Ile, β-Ala, Ala, Lys,

[0957] Asn, Pro, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, Lys(Ac), α-

[0958] MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), Gln, Asp or Cys;

[0959] X6a is Thr, 2-aminoisobutyric acid, Asp, Dab, Gly, Pro, Ser, α-MeGln,

[0960] α-MeLys, α-MeLeu, α-MeAsn, α-MeThr, α-MeSer or Val.

[0961] In some embodiments, the amino, carboxyl, hydroxyl, and thiol groups on the side chain of each of X3a to X6a are independently protected with a suitable protecting group.

[0962] In some embodiments, the compound of formula (V') is R 7 -Pen-Asn-Thr-R 5 .

[0963] In some embodiments, the compound of formula (V') has the following structure:

[0964]

[0965] In some embodiments, the compound of formula (V') is prepared by separating the compound of formula (IX) from

[0966] R 6 -X3a-X4a-R 3

[0967] (IX)

[0968] and a compound of formula (X)

[0969] R 2 -X5a-X6a-R 5

[0970] (X)

[0971] The reaction is prepared to form an amide bond between X4a and X5a;

[0972] where R 2 H; R 3 OH or OP 2 , R 5 OH or OP 2 ; R 6 H or P 1 , P 1 is an amino protecting group, and each P 2 is independently a carboxyl protecting group.

[0973] In R 3 For OP 2 In the case of carboxyl protecting groups (P 2 ) can be removed in situ during the coupling process.

[0974] In some embodiments, the compound of formula (IX) is R 6 -X4a-R 3 , where R 3 is OH, and R 6 P 1 And P 1 is an amino protecting group.

[0975] In some embodiments, an ammonium coupling reagent is used to form the amide bond.

[0976] In some embodiments, the amide bond is formed in the presence of O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate (TBTU) and diisopropylethylamine (DIPEA).

[0977] In some embodiments, R 5 For OP 2 And P 2 C 1-6Alkyl; and / or R 6 P 1 And P 1 It is Fmoc.

[0978] In some embodiments, when R 6 P 1 When the compound of formula (IX) is reacted with the compound of formula (X) to obtain a protected precursor of the compound of formula (V). The terminal amino group is deprotected to remove P 1 , we get the formula R 7 -X3a-X4a-X5a-X6a-R 5 A compound wherein R 7 H or P 1 .

[0979] In some embodiments of the compound of Formula (IX):

[0980] R 3 OH or OP 2 ;

[0981] R 6 H or P 1 ;

[0982] P 1 is an amino protecting group;

[0983] P 2 is a carboxyl protecting group;

[0984] X3a does not exist or is any amino acid residue;

[0985] X4a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen or Pen(sulfoxide).

[0986] In some embodiments, the amino, carboxyl, hydroxyl, and thiol groups on the side chain of each of X3a to X4a are independently protected with a suitable protecting group.

[0987] In some embodiments, the compound of formula (IX) is R 6 -Pen-R 3 .

[0988] In some embodiments, the compound of formula (IX) has the following structure:

[0989]

[0990] In some embodiments of the compound of Formula (X):

[0991] R 2 is H;

[0992] R 5 NH2 or NHP 1 ;

[0993] P 1 is an amino protecting group;

[0994] X5a is Cit, Glu, Gly, substituted Gly, Leu, Ile, β-Ala, Ala, Lys,

[0995] Asn, Pro, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, Lys(Ac), α-

[0996] MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), Gln, Asp or Cys;

[0997] X6a is Thr, 2-aminoisobutyric acid, Asp, Dab, Gly, Pro, Ser, α-MeGln,

[0998] α-MeLys, α-MeLeu, α-MeAsn, α-MeThr, α-MeSer or Val.

[0999] In some embodiments, the amino, carboxyl, hydroxyl, and thiol groups on the side chain of each of X5a to X6a are independently protected with a suitable protecting group.

[1000] In some embodiments, the compound of formula (X) is R 2 -Asn-Thr-R 5 .

[1001] In some embodiments, the compound of formula (X) has the following structure:

[1002]

[1003] In some embodiments, the compound of formula (X) is prepared by deprotecting a protected precursor of the compound of formula (X). In some embodiments, the protected precursor of the compound of formula (X) has the following structure:

[1004]

[1005] Preparation of compounds of formula (X)

[1006] The process for preparing the compound of formula (V) may further comprise the step of preparing the compound of formula (X).

[1007] In some embodiments, the method of preparing a compound of formula (X) comprises making a compound of formula R6 -X5a-R 3 The compound of formula R 2 -X6a-R 5 to form an amide bond between X5a and X6a, wherein R 2 H, R 3 OH, R 5 For OP 2 , R 6 P 1 , P 1 is an amino protecting group, and P 2 A carboxyl protecting group.

[1008] In some embodiments, amide bonds are formed using a carbodiimide coupling reagent, optionally in the presence of an additive.

[1009] In some embodiments, the amide bond is formed in the presence of N-ethyl-N'-dimethylaminopropylcarbodiimide (EDCI) and 1-hydroxy-7-azabenzotriazole (HOAt).

[1010] In some embodiments, R 5 For OP 2 And P 2 C 1-6 Alkyl; and / or R 6 P 1 And P 1 For Cbz.

[1011] In some embodiments, when R 6 P 1 When R 6 -X5a-R 3 The compound of formula R 2 -X6a-R 5 The protected precursor of the compound of formula (X) is obtained by reacting the terminal amino group to remove P 1 , to obtain a compound of formula (X).

[1012] Preparation of compounds of formula (VI)

[1013] The method for preparing a single-cyclic peptide fragment may further comprise the step of preparing a compound of formula (VI).

[1014] In some embodiments, the method of preparing a compound of formula (VI) comprises making a compound of formula (XI):

[1015] R 2 -X8a-X9a-X10a-R 5

[1016] (XI)

[1017] With R 6 -X7a-R 3 reacts to form an amide bond between X7a and X8a; wherein

[1018] R 2 is H;

[1019] R 3 OH or OP 2 ;

[1020] R 5 OH or P 2 ;

[1021] R 6 H or P 1 ;and

[1022] Each P 1 is an amino protecting group; and

[1023] Each P 2 is independently a carboxyl protecting group.

[1024] In R 3 For OP 2 In the case of carboxyl protecting groups (P 2 ) can be removed in situ during the coupling process.

[1025] In some embodiments, amide bonds are formed using a carbodiimide coupling reagent, optionally in the presence of an additive.

[1026] In some embodiments, the amide bond is formed in the presence of N-ethyl-N'-dimethylaminopropylcarbodiimide (EDCI) and ethylcyanoacetaldehyde 2-oxime (Oxyma Pure).

[1027] In some embodiments, R 5 P 2 And P 2 C 1-6 Alkyl; and / or R 6 P 1 And P 1 It is Fmoc.

[1028] In some embodiments, when R 6 P 1 When the compound of formula (XI) is reacted with the compound of formula R 6 -X7a-R 3 The compound is reacted to obtain a protected precursor of the compound of formula (VI). The terminal amino group is deprotected to remove P 1 , to obtain the compound of formula (VI).

[1029] In some embodiments of the compound of Formula (XI):

[1030] R 2 is H;

[1031] R 5 NH2 or NHP 1 ;

[1032] P 1 is an amino protecting group;

[1033] X8a is Gln, α-Me-Lys, α-MeLeu, α-MeLys(Ac), β-homoGln, Cit,

[1034] Glu, Phe, Asn, Thr, Val, 2-aminoisobutyric acid, α-MeGln, α-MeAsn,

[1035] Lys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), 1Nal, 2Nal or Trp;

[1036] X9a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide);

[1037] X10a is unsubstituted Phe, or Phe substituted with halo, alkyl, haloalkyl, hydroxy, alkoxy, carboxyl, carboxamido, 2-aminoethoxy, or 2-acetylaminoethoxy.

[1038] In some embodiments, the amino, carboxyl, hydroxyl, and thiol groups on the side chain of each of X8a to X10a are independently protected with a suitable protecting group.

[1039] In some embodiments, the compound of formula (XI) is R 2 -Lys(Ac)-Pen-Tyr(2ea)-R 5 .

[1040] In some embodiments, the compound of formula (XI) has the following structure:

[1041]

[1042] In some embodiments, the compound of formula (XI) is prepared by deprotecting a protected precursor of the compound of formula (XI). In some embodiments, the protected precursor of the compound of formula (XI) has the following structure:

[1043]

[1044] Preparation of compounds of formula (XI)

[1045] The process for preparing the compound of formula (VI) may further comprise the step of preparing the compound of formula (XI).

[1046] In some embodiments, the method of preparing a compound of formula (XI) comprises reacting a compound of formula (XII):

[1047] R 2 -X9a-X10a-R 5

[1048] With R 6 -X8a-R 3 reacts to form an amide bond between X8a and X9a; wherein

[1049] R 2 is H;

[1050] R 3 OH or OP 2 ;

[1051] R 5 OH or P 2 ;

[1052] R 6 H or P 1 ;and

[1053] Each P 1 is an amino protecting group; and

[1054] Each P 2 is independently a carboxyl protecting group.

[1055] In R 3 For OP 2 In the case of carboxyl protecting groups (P 2 ) can be removed in situ during the coupling process.

[1056] In some embodiments, amide bonds are formed using a carbodiimide coupling reagent, optionally in the presence of an additive.

[1057] In some embodiments, the amide bond is formed in the presence of N-ethyl-N'-dimethylaminopropylcarbodiimide (EDCI) and ethyl cyanohydroxyiminoacetate (Oxyma Pure).

[1058] In some embodiments, R 5 P 2 And P 2 C 1-6 Alkyl; and / or R 6 It is Fmoc.

[1059] In some embodiments, when R 6 P 1 When the compound of formula (XII) is reacted with the compound of formula R 6 -X8a-R 3 The compound is reacted to obtain a protected precursor of the compound of formula (XI). The terminal amino group is deprotected to remove P 1 , to obtain the compound of formula (XI).

[1060] In some embodiments, the method for preparing a compound of formula (XI) further comprises the step of preparing a compound of formula (XII) comprising: 6 -X9a-R 3 Compounds with R 2 -X10a-R 5 to form an amide bond between X9a and X10a, wherein R 2 H, R 3 OH, R 5 OH or P 2 , R 6 H or P 1 , P 1 is an amino protecting group, and P 2 is a carboxyl protecting group. An amide bond is formed using a carbodiimide coupling reagent, optionally in the presence of an additive. An amide bond is formed in the presence of N-ethyl-N'-dimethylaminopropylcarbodiimide (EDCI) and ethyl cyanohydroxyiminoacetate (Oxyma Pure). In some embodiments, R 5 P 1 And P 1 C 1-6 Alkyl; and / or R 6 It is Fmoc.

[1061] In some embodiments, when R 6 P 1 When R 6 -X9a-R 3 Compounds with R 2 -X10a-R 5 The protected precursor of the compound of formula (XII) is obtained by reacting the terminal amino group to remove P 1 , to obtain the compound of formula (XII).

[1062] In some embodiments of the compound of Formula (XII):

[1063] R 2 is H;

[1064] R5 NH2 or NHP 1 ;

[1065] P 1 is an amino protecting group;

[1066] X9a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide);

[1067] X10a is unsubstituted Phe, or Phe substituted with halo, alkyl, haloalkyl, hydroxy, alkoxy, carboxyl, carboxamido, 2-aminoethoxy, or 2-acetylaminoethoxy.

[1068] In some embodiments, the amino, carboxyl, hydroxyl, and thiol groups on the side chain of each of X9a to X10a are independently protected with a suitable protecting group.

[1069] In some embodiments, the compound of formula (XII) is R 2 -Pen-Tyr(2ea)-R 5 .

[1070] In some embodiments, the compound of formula (XII) has the following structure:

[1071]

[1072] In some embodiments, the compound of formula (XII) is prepared by deprotecting a protected precursor of the compound of formula (XII). In some embodiments, the protected precursor of the compound of formula (XII) has the following structure:

[1073]

[1074] Other embodiments of the present invention

[1075] The exemplary compounds that can be used in the method of the present invention will now be described with reference to exemplary synthesis schemes for their general preparation and subsequent specific examples below. Those skilled in the art will recognize that, in order to obtain the various compounds herein, the starting materials can be appropriately selected so that, when protected or unprotected as needed, the final desired substituent will be carried throughout the reaction scheme to obtain the desired product. Alternatively, it may be necessary or desirable to replace the final desired substituent with a suitable group that can undergo the entire reaction scheme and, where appropriate, be replaced with the desired substituent. The reaction can be carried out between the melting point and reflux temperature of the solvent, and is preferably carried out between 0° C. and the reflux temperature of the solvent. Conventional heating or microwave heating can be used to heat the reaction. The reaction can also be carried out in a closed pressure vessel at a temperature higher than the normal reflux temperature of the solvent.

[1076] In the synthetic method described herein, peptide extension is performed in solution, and the synthetic scheme can achieve large-scale production of peptides, reduce the use of excess reagents and solvents, and facilitate purification of reaction intermediates, thus complying with the principles of green chemistry.

[1077] In one embodiment, the invention relates to compounds of formula (AV), (A-VI) or (A-VII),

[1078]

[1079] in:

[1080] P 11 is H, Fmoc, Cbz or BOC;

[1081] P 12 is H, Fmoc, Cbz or BOC;

[1082] P 13 is H, Fmoc, Cbz or BOC;

[1083] P 14 H or C (1-4) alkyl;

[1084] or a pharmaceutically acceptable salt thereof.

[1085] In one embodiment, the invention relates to compounds of formula (A-II), (A-III) or (A-IV),

[1086]

[1087] in:

[1088] P 4 is H, Fmoc, Cbz or BOC;

[1089] P 5 is H, trityl or Acm;

[1090] P 6 H or C (1-4) alkyl;

[1091] P 7 is H, Fmoc, Cbz or BOC;

[1092] P 8 is H or Ac;

[1093] P 9 is H, Fmoc, Cbz or BOC;

[1094] P 10 is H, Fmoc, Cbz or BOC;

[1095] or a pharmaceutically acceptable salt thereof.

[1096] In one aspect, the present invention relates to a compound of formula (AI)

[1097]

[1098] in:

[1099] P 0 H or C (1-4) alkyl;

[1100] P 1 is H, tert-butyl, Bn or Bz;

[1101] P 2 is H, trityl or Acm;

[1102] P 3 is H, Fmoc, Cbz or BOC;

[1103] or a pharmaceutically acceptable salt thereof.

[1104] In some embodiments, the compound of formula (AI) is

[1105] or a pharmaceutically acceptable salt thereof. Some embodiments include formula (A-II)

[1106]

[1107] in:

[1108] P 4 is H, Fmoc, Cbz or BOC;

[1109] P5 is H, trityl or Acm;

[1110] P 6 H or C (1-4) alkyl;

[1111] P 7 is H, Fmoc, Cbz or BOC;

[1112] or a pharmaceutically acceptable salt thereof.

[1113] In some embodiments, the compound of formula (A-II) is

[1114]

[1115] or a pharmaceutically acceptable salt thereof.

[1116] In one embodiment, the compound has the structure of formula (A-III)

[1117]

[1118] in:

[1119] P 5 is H, trityl or Acm;

[1120] P 6 H or C (1-4) alkyl;

[1121] P 7 is H, Fmoc, Cbz or BOC;

[1122] P 8 is H or Ac;

[1123] P 9 is H, Fmoc, Cbz or BOC;

[1124] or a pharmaceutically acceptable salt thereof.

[1125] In some embodiments, the compound of formula (A-III) is

[1126]

[1127] or a pharmaceutically acceptable salt thereof.

[1128] In one embodiment, the compound has the structure of formula (A-IV)

[1129]

[1130] in:

[1131] P6 H or C (1-4) alkyl;

[1132] P 7 is H, Fmoc, Cbz or BOC;

[1133] P 8 is H or Ac;

[1134] P 10 is H, Fmoc, Cbz or BOC;

[1135] or a pharmaceutically acceptable salt thereof.

[1136] In one embodiment, the compound of formula (A-IV) is

[1137]

[1138] or a pharmaceutically acceptable salt thereof.

[1139] In one embodiment, the compound has the structure of formula (AV)

[1140]

[1141] in:

[1142] P 11 is H, Fmoc, Cbz or BOC;

[1143] or a pharmaceutically acceptable salt thereof.

[1144] In some embodiments, the compound of formula (AV) is

[1145] or a pharmaceutically acceptable salt thereof. In one embodiment, the compound has the structure of formula (A-VI)

[1146]

[1147] in:

[1148] P 12 is H, Fmoc, Cbz or BOC;

[1149] or a pharmaceutically acceptable salt thereof.

[1150] In some embodiments, the compound of formula (A-VI) is

[1151]

[1152] or a pharmaceutically acceptable salt thereof.

[1153] In one embodiment, the compound has the structure of Formula (A-VII)

[1154]

[1155] in:

[1156] P 13 is H, Fmoc, Cbz or BOC;

[1157] P 14 H or C (1-4) alkyl;

[1158] or a pharmaceutically acceptable salt thereof.

[1159] In some embodiments, the compound of formula (A-VII) is

[1160]

[1161] or a pharmaceutically acceptable salt thereof.

[1162] In one embodiment, the compound has the structure of formula (A-VIII)

[1163]

[1164] in:

[1165] P 15 is H, Fmoc, Cbz or BOC;

[1166] P 16 H or C (1-4) alkyl;

[1167] or a pharmaceutically acceptable salt thereof.

[1168] In some embodiments, the compound of formula (A-VIII) is

[1169] or a pharmaceutically acceptable salt thereof. In one embodiment, the compound has the structure of formula (A-IX)

[1170]

[1171] in:

[1172] P 15 is H, Fmoc, Cbz or BOC;

[1173] P 14 H or C (1-4) alkyl;

[1174] or a pharmaceutically acceptable salt thereof.

[1175] In some embodiments, the compound of formula (A-IX) is

[1176]

[1177] or a pharmaceutically acceptable salt thereof.

[1178] In one embodiment, the compound has the structure of formula (AX)

[1179]

[1180] in:

[1181] P 1 is H, tert-butyl, Bn or Bz;

[1182] P 2 is H, trityl or Acm;

[1183] P 3 is H, Fmoc, Cbz or BOC;

[1184] P 5 is H, trityl or Acm;

[1185] P 6 H or C (1-4) alkyl;

[1186] P 7 is H, Fmoc, Cbz or BOC;

[1187] P 8 is H or Ac;

[1188] or a pharmaceutically acceptable salt thereof.

[1189] In some embodiments, the compound of formula (AX) is

[1190]

[1191] or a pharmaceutically acceptable salt thereof.

[1192] In one embodiment, the compound has the structure of formula (A-XI)

[1193]

[1194] in:

[1195] P 1 is H, tert-butyl, Bn or Bz;

[1196] P 3 is H, Fmoc, Cbz or BOC;

[1197] P 6 H or C (1-4) alkyl;

[1198] P 7 is H, Fmoc, Cbz or BOC;

[1199] P 8 is H or Ac;

[1200] or a pharmaceutically acceptable salt thereof.

[1201] In some embodiments, the compound of formula (A-XI) is

[1202]

[1203] or a pharmaceutically acceptable salt thereof.

[1204] Some embodiments relate to methods of preparing compounds of compound 26, wherein the Ac-[1-7]-OH- ring is reacted with H-[8-13]-NH2:

[1205]

[1206] Compound 25 was obtained by reaction in the presence of diisopropylcarbodiimide and Oxyma-B, followed by acid-mediated removal of the tert-butyl groups from threonine and glutamic acid and the butoxycarbonyl group from aminoethoxyphenylalanine to afford compound 26.

[1207] In some embodiments, H[8-13]NH2 is formed by reacting Fmoc-2-Nal-THPGly-OH with H-Glu(OtBu)-Asn-3-Pal-Sar-NH2.

[1208]

[1209] In the presence of (7-azabenzotriazol-1-yloxy)tripyrrolidinylphosphonium hexafluorophosphate and diisopropylethylamine, Fmoc[8-13]NH2 is formed, which is then reacted with 1,8-diazabicyclo[5.4.0]undec-7-ene.

[1210] In some embodiments, Fmoc-2-Nal-THPGly-OH is formed by reacting H-THPGly-OH with Fmoc-2-Nal-OH in the presence of N,O-bis(trimethylsilyl)acetamide.

[1211]

[1212] In some embodiments, wherein Z-Glu(OtBu)-OH is reacted with N-hydroxysuccinimide and diisopropylcarbodiimide, followed by reaction with H-Asn-3-Pal-Sar-NH2 to form Cbz-Glu(OtBu)-Asn-3-Pal-Sar-NH2, followed by catalytic hydrogenation to form H-Glu(OtBu)-Asn-3-Pal-Sar-NH2:

[1213]

[1214] In some embodiments, Z-Asn-OH is reacted with N-hydroxysuccinimide and diisopropylcarbodiimide, followed by reaction with H-3-Pal-Sar-NH2 to form Cbz-[11-13]-NH2, followed by catalytic hydrogenation to form H-Asn-3-Pal-Sar-NH2:

[1215]

[1216] In some embodiments, Boc-3-Pal-OH is reacted with pivaloyl chloride in the presence of pyridine and N-methylmorpholine, followed by reaction with H-Sar-NH2 to form Boc-3-Pal-Sar-NH2, followed by acid-mediated removal of the butoxycarbonyl group to form H-3-Pal-Sar-NH2:

[1217]

[1218] Some embodiments relate to a method for preparing Ac-[1-7]-OMe, wherein Ac-Pen(Trt)-Asn-Thr(tBu)-OH is reacted with H-7Me-Trp-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe in the presence of diisopropylcarbodiimide and OxymaB, followed by reaction with iodine in the presence of potassium iodide:

[1219]

[1220] In some embodiments, H-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe is reacted with Fmoc-Trp(7Me)-OH in the presence of N,N,N'N'-tetramethyl-O-(benzotriazol-1-yl)uronium tetrafluoroborate and diisopropylethylamine to form Fmoc-7Me-Trp-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe, followed by reaction with 1,8-diazabicyclo[5,4,0]undec-7-ene to form H-7Me-Trp-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe:

[1221]

[1222] In some embodiments, H-Pen(Acm)-Tyr(2-Boc-ea)-OMe is reacted with Fmoc-Lys(Ac)-OH in the presence of N,N,N'N'-tetramethyl-O-(benzotriazol-1-yl)uronium tetrafluoroborate and diisopropylethylamine to form Fmoc-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe, which is then reacted with 1,8-diazabicyclo[5,4,0]undec-7-ene to form H-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe:

[1223]

[1224] In some embodiments, H-Tyr(2-Boc-ea)-OMe is reacted with Fmoc-Pen(Acm)-OH in the presence of Oxyma Pure and diisopropylcarbodiimide to form Fmoc-Pen(Acm)-Tyr(2-Boc-ea)-OMe, which is then reacted with 1,8-diazabicyclo[5,4,0]undec-7-ene to form H-Pen(Acm)-Tyr(2-Boc-ea)-OMe:

[1225]

[1226] In some embodiments, H-Asn-Thr(tBu)-OMe is reacted with Fmoc-Pen(Trt)-OH in the presence of N,N,N'N'-tetramethyl-O-(benzotriazol-1-yl)uronium tetrafluoroborate and diisopropylethylamine to form Fmoc-Pen(Trt)-Asn-Thr(tBu)-OMe, followed by reaction with 1,8-diazabicyclo[5,4,0]undec-7-ene to form H-Pen(Trt)-Asn-Thr(tBu)-OMe, followed by reaction with acetic anhydride to form Ac-Pen(Trt)-Asn-Thr(tBu)-OMe, followed by reaction with lithium hydroxide to form Ac-Pen(Trt)-Asn-Thr(tBu)-OH:

[1227]

[1228] Some embodiments relate to a method for preparing (A-XII) by reacting (A-XI) with (A-IX)

[1229]

[1230] in:

[1231] P 1 is H, tert-butyl, Bn or Bz;

[1232] P 3 is H, Fmoc, Cbz or BOC;

[1233] P 6 is H;

[1234] P 7 is H, Fmoc, Cbz or BOC;

[1235] P 8 is H or Ac;

[1236] P 14 H or C (1-4) alkyl;

[1237] P 15 is H;

[1238] or a pharmaceutically acceptable salt thereof.

[1239] Some embodiments relate to a method of preparing (A-IX) by reacting (A-VII) with (A-VIII) in the presence of a reagent selected from:

[1240] Oxyma B and diisopropylcarbodiimide,

[1241] Oxyma Pure and diisopropylcarbodiimide,

[1242] (7-Azabenzotriazol-1-yloxy)tripyrrolidinophosphonium hexafluorophosphate and diisopropylethylamine,

[1243] Pivaloyl chloride, pyridine and N-methylmorpholine, with or without N,O-bis(trimethylsilyl)acetamide,

[1244] N,N,N'N'-Tetramethyl-O-(benzotriazol-1-yl)uronium tetrafluoroborate and diisopropylethylamine,

[1245] N-hydroxysuccinimide and diisopropylcarbodiimide, or

[1246] Oxyma Pure and N-ethyl-N'-(3-dimethylaminopropyl)carbodiimide

[1247]

[1248] in:

[1249] P 13 is H;

[1250] P 14 H or C (1-4) alkyl;

[1251] P 15 is H, Fmoc, Cbz or BOC;

[1252] P 16 is H;

[1253] or a pharmaceutically acceptable salt thereof.

[1254] Some embodiments relate to a method of preparing (A-VIII) by reacting (A-VIII-A) with (A-VIII-B) in the presence of a reagent selected from:

[1255] Oxyma B and diisopropylcarbodiimide,

[1256] Oxyma Pure and diisopropylcarbodiimide,

[1257] (7-Azabenzotriazol-1-yloxy)tripyrrolidinophosphonium hexafluorophosphate and diisopropylethylamine,

[1258] Pivaloyl chloride, pyridine, and N-methylmorpholine, with or without N,O-bis(trimethylsilyl)

[1259] Acetamide,

[1260] N,N,N'N'-Tetramethyl-O-(benzotriazol-1-yl)uronium tetrafluoroborate and diisopropylethylamine,

[1261] N-hydroxysuccinimide and diisopropylcarbodiimide, or

[1262] Oxyma Pure and N-ethyl-N'-(3-dimethylaminopropyl)carbodiimide

[1263]

[1264] in:

[1265] P 15 is H, Fmoc, Cbz or BOC;

[1266] P 16 H or C (1-4) alkyl;

[1267] or a pharmaceutically acceptable salt thereof.

[1268] Some embodiments relate to a method of preparing (A-VII) by reacting (A-VI) with (A-VII-A) in the presence of a reagent selected from:

[1269] Oxyma B and diisopropylcarbodiimide,

[1270] Oxyma Pure and diisopropylcarbodiimide,

[1271] (7-Azabenzotriazol-1-yloxy)tripyrrolidinophosphonium hexafluorophosphate and diisopropylethylamine,

[1272] Pivaloyl chloride, pyridine and N-methylmorpholine, with or without N,O-bis(trimethylsilyl)acetamide,

[1273] N,N,N'N'-Tetramethyl-O-(benzotriazol-1-yl)uronium tetrafluoroborate and diisopropylethylamine,

[1274] N-hydroxysuccinimide and diisopropylcarbodiimide, or

[1275] Oxyma Pure and N-ethyl-N'-(3-dimethylaminopropyl)carbodiimide

[1276]

[1277] in:

[1278] P 12 is H;

[1279] P 13 is H, Fmoc, Cbz or BOC;

[1280] P 14 H or C(1-4) alkyl;

[1281] or a pharmaceutically acceptable salt thereof.

[1282] Some embodiments relate to a method of preparing (A-VI) by reacting (AV) with (A-VI-A) in the presence of a reagent selected from:

[1283] Oxyma B and diisopropylcarbodiimide,

[1284] Oxyma Pure and diisopropylcarbodiimide,

[1285] (7-Azabenzotriazol-1-yloxy)tripyrrolidinophosphonium hexafluorophosphate and diisopropylethylamine,

[1286] Pivaloyl chloride, pyridine, and N-methylmorpholine, with or without N,O-bis(trimethylsilyl)

[1287] Acetamide,

[1288] N,N,N'N'-Tetramethyl-O-(benzotriazol-1-yl)uronium tetrafluoroborate and diisopropylethylamine,

[1289] N-hydroxysuccinimide and diisopropylcarbodiimide, or

[1290] Oxyma Pure and N-ethyl-N'-(3-dimethylaminopropyl)carbodiimide

[1291]

[1292] in:

[1293] P 11 is H;

[1294] P 12 is H, Fmoc, Cbz or BOC;

[1295] or a pharmaceutically acceptable salt thereof.

[1296] Some embodiments relate to a method for preparing (AV) by reacting H-Sar-NH2 with (AVA) in the presence of a reagent selected from the group consisting of:

[1297] Oxyma B and diisopropylcarbodiimide,

[1298] Oxyma Pure and diisopropylcarbodiimide,

[1299] (7-Azabenzotriazol-1-yloxy)tripyrrolidinophosphonium hexafluorophosphate and diisopropylethylamine,

[1300] Pivaloyl chloride, pyridine and N-methylmorpholine, with or without N,O-bis(trimethylsilyl)acetamide,

[1301] N,N,N'N'-Tetramethyl-O-(benzotriazol-1-yl)uronium tetrafluoroborate and diisopropylethylamine,

[1302] N-hydroxysuccinimide and diisopropylcarbodiimide, or

[1303] Oxyma Pure and N-ethyl-N'-(3-dimethylaminopropyl)carbodiimide

[1304]

[1305] in:

[1306] P 11 is H, Fmoc, Cbz or BOC;

[1307] or a pharmaceutically acceptable salt thereof.

[1308] Some embodiments relate to a method of preparing (AX) by reacting (AI) with (A-IV) in the presence of a reagent selected from:

[1309] Oxyma B and diisopropylcarbodiimide,

[1310] Oxyma Pure and diisopropylcarbodiimide,

[1311] (7-Azabenzotriazol-1-yloxy)tripyrrolidinophosphonium hexafluorophosphate and diisopropylethylamine,

[1312] Pivaloyl chloride, pyridine and N-methylmorpholine, with or without N,O-bis(trimethylsilyl)acetamide,

[1313] N,N,N'N'-Tetramethyl-O-(benzotriazol-1-yl)uronium tetrafluoroborate and diisopropylethylamine,

[1314] N-hydroxysuccinimide and diisopropylcarbodiimide, or

[1315] Oxyma Pure and N-ethyl-N'-(3-dimethylaminopropyl)carbodiimide

[1316]

[1317] in:

[1318] P 0 is H;

[1319] P 1 is H, tert-butyl, Bn or Bz;

[1320] P 2 is H, trityl or Acm;

[1321] P 3 is H, Fmoc, Cbz or BOC;

[1322] P 5 is H, trityl or Acm;

[1323] P 6 H or C (1-4) alkyl;

[1324] P 7 is H, Fmoc, Cbz or BOC;

[1325] P 8 is H or Ac;

[1326] P 10 is H;

[1327] or a pharmaceutically acceptable salt thereof.

[1328] Some embodiments relate to a method of preparing (A-IV) by reacting (A-III) with (A-IV-A) in the presence of a reagent selected from:

[1329] Oxyma B and diisopropylcarbodiimide,

[1330] Oxyma Pure and diisopropylcarbodiimide,

[1331] (7-Azabenzotriazol-1-yloxy)tripyrrolidinophosphonium hexafluorophosphate and diisopropylethylamine,

[1332] Pivaloyl chloride, pyridine and N-methylmorpholine, with or without N,O-bis(trimethylsilyl)acetamide,

[1333] N,N,N'N'-Tetramethyl-O-(benzotriazol-1-yl)uronium tetrafluoroborate and diisopropylethylamine,

[1334] N-hydroxysuccinimide and diisopropylcarbodiimide, or

[1335] Oxyma Pure and N-ethyl-N'-(3-dimethylaminopropyl)carbodiimide

[1336]

[1337] in:

[1338] P5 is H, trityl or Acm;

[1339] P 6 H or C (1-4) alkyl;

[1340] P 7 is H, Fmoc, Cbz or BOC;

[1341] P 8 is H or Ac;

[1342] P 9 is H;

[1343] P 10 is H, Fmoc, Cbz or BOC;

[1344] or a pharmaceutically acceptable salt thereof.

[1345] Some embodiments relate to a method of preparing (A-III) by reacting (A-II) with (A-III-A) in the presence of a reagent selected from:

[1346] Oxyma B and diisopropylcarbodiimide,

[1347] Oxyma Pure and diisopropylcarbodiimide,

[1348] (7-Azabenzotriazol-1-yloxy)tripyrrolidinophosphonium hexafluorophosphate and diisopropylethylamine,

[1349] Pivaloyl chloride, pyridine and N-methylmorpholine, with or without N,O-bis(trimethylsilyl)acetamide,

[1350] N,N,N'N'-Tetramethyl-O-(benzotriazol-1-yl)uronium tetrafluoroborate and diisopropylethylamine,

[1351] N-hydroxysuccinimide and diisopropylcarbodiimide, or

[1352] Oxyma Pure and N-ethyl-N'-(3-dimethylaminopropyl)carbodiimide

[1353]

[1354] in

[1355] P 4 is H;

[1356] P 5 is H, trityl or Acm;

[1357] P 6H or C (1-4) alkyl;

[1358] P 7 is H, Fmoc, Cbz or BOC;

[1359] P 8 is H or Ac;

[1360] P 9 is H, Fmoc, Cbz or BOC;

[1361] or a pharmaceutically acceptable salt thereof.

[1362] Some embodiments relate to a method of preparing (A-II) by reacting (A-II-A) with (A-II-B) in the presence of a reagent selected from:

[1363] Oxyma B and diisopropylcarbodiimide,

[1364] Oxyma Pure and diisopropylcarbodiimide,

[1365] (7-Azabenzotriazol-1-yloxy)tripyrrolidinophosphonium hexafluorophosphate and diisopropylethylamine,

[1366] Pivaloyl chloride, pyridine, and N-methylmorpholine, with or without N,O-bis(trimethylsilyl)

[1367] Acetamide,

[1368] N,N,N'N'-Tetramethyl-O-(benzotriazol-1-yl)uronium tetrafluoroborate and diisopropylethylamine,

[1369] N-hydroxysuccinimide and diisopropylcarbodiimide, or

[1370] Oxyma Pure and N-ethyl-N'-(3-dimethylaminopropyl)carbodiimide

[1371]

[1372] in:

[1373] P 4 is H, Fmoc, Cbz or BOC;

[1374] P 5 is H, trityl or Acm;

[1375] P 6 H or C (1-4) alkyl;

[1376] P 7is H, Fmoc, Cbz or BOC;

[1377] or a pharmaceutically acceptable salt thereof.

[1378] Some embodiments relate to a method of preparing (AI) by reacting (AIA) with (AIB) in the presence of a reagent selected from:

[1379] Oxyma B and diisopropylcarbodiimide,

[1380] Oxyma Pure and diisopropylcarbodiimide,

[1381] (7-Azabenzotriazol-1-yloxy)tripyrrolidinophosphonium hexafluorophosphate and diisopropylethylamine,

[1382] Pivaloyl chloride, pyridine and N-methylmorpholine, with or without N,O-bis(trimethylsilyl)acetamide,

[1383] N,N,N'N'-Tetramethyl-O-(benzotriazol-1-yl)uronium tetrafluoroborate and diisopropylethylamine,

[1384] N-hydroxysuccinimide and diisopropylcarbodiimide, or

[1385] Oxyma Pure and N-ethyl-N'-(3-dimethylaminopropyl)carbodiimide

[1386]

[1387] in:

[1388] P 0 H or C (1-4) alkyl;

[1389] P 1 is H, tert-butyl, Bn or Bz;

[1390] P 2 is H, trityl or Acm;

[1391] P 3 is H, Fmoc, Cbz or BOC;

[1392] or a pharmaceutically acceptable salt thereof.

[1393] The product of compound 26 or a pharmaceutically acceptable salt thereof is prepared by a process comprising the steps of:

[1394] (a) In the presence of (7-azabenzotriazol-1-yloxy)tripyrrolidinylphosphonium hexafluorophosphate and diisopropylethylamine, Fmoc-2-Nal-THPGly-OH is reacted with H-Glu(OtBu)-Asn-3-Pal-Sar-NH2:

[1395]

[1396] Fmoc[8-13]NH2 is formed, which then reacts with 1,8-diazabicyclo[5.4.0]undec-7-ene to form H[8-13]NH2;

[1397] (b) Ac-Pen(Trt)-Asn-Thr(tBu)-OH is reacted with H-7Me-Trp-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe in the presence of diisopropylcarbodiimide and Oxyma B, followed by reaction with iodine in the presence of potassium iodide:

[1398]

[1399] Formation of Ac-[1-7]-OMe;

[1400] (c) reacting the Ac-[1-7]-OH- ring with H-[8-13]-NH2:

[1401]

[1402] In some embodiments, the above reaction is carried out in the presence of diisopropylcarbodiimide and Oxyma-B, followed by acid-mediated removal of the tert-butyl group from threonine and glutamate, and removal of the butoxycarbonyl group from aminoethoxyphenylalanine; to form the product of compound 26 or a pharmaceutically acceptable salt thereof.

[1403] Example

[1404] The present invention will now be described in more detail by way of specific examples.

[1405] The following reaction schemes may aid in understanding the reactions discussed throughout the following examples.

[1406] Reaction Scheme I-1

[1407]

[1408] Reaction Scheme I-2

[1409]

[1410] Reaction Scheme I-3

[1411]

[1412] Reaction Scheme I-4

[1413]

[1414] Example I-1: Synthesis of Cbz-Asn-Thr(tBu)-OMe

[1415]

[1416] To a solution of Cbz-Asn-OH (203.1 kg, 750 mol, 1.1 equiv) was added H-Thr(tBu)-OMe*HCl (160.1 kg, 681 mol, 1.0 equiv) and MeCN (3.5 vol, 560 L, 443 kg). HOAt (48 kg, 341 mol, 0.5 equiv) was added portionwise over 2.5 hours, followed by the dropwise addition of DIPEA (202 kg, 1498 mol, 2.2 equiv) over 2.1 hours. EDCI (163 kg, 817 mol, 1.2 equiv) was then added portionwise at -5.5°C over 4 hours, and the mixture was stirred at this temperature for 8 hours, then at 5°C to 15°C for 16 hours.

[1417] IPAc (12.5 volumes, 1931 L, 1680 kg) and 5% citric acid (5 volumes, 770 L, 770 kg) were added to the reaction mixture at 5°C to 15°C, and the organic phase was separated and washed twice with 5% NaHCO (5 volumes, 770 L, 770 kg) and once with 23% aqueous NaCl (3 volumes, 473 L, 473 kg). The organic phase was concentrated to 9 volumes (relative to H-Thr(tBu)-OMe*HCl) under reduced pressure at 40°C, followed by the addition of IPAc (3 volumes, 462 L, 402 kg) and the mixture was concentrated again to 9 volumes (relative to H-Thr(tBu)-OMe*HCl). n-Heptane (16 volumes, 2600 L, 1768 kg) was added dropwise to the solution at 25°C to 35°C over 5 hours. The mixture was then stirred at 25°C to 35°C for 1 hour, cooled to -5°C to 5°C over 5 hours, and then stirred at -5°C to 5°C for 10.5 hours. More n-heptane (2 volumes, 300 L, 204 kg) was added dropwise at -5°C to 5°C over 1 hour, and the mixture was then stirred at -5°C to 5°C for 4.5 hours and filtered. The filter cake was washed with pre-cooled IPAc / n-heptane (v / v) (2.4 volumes, 371 kg), and the product was dried under reduced pressure at 40°C for 17 hours to give 275.1 kg (90.0% yield, 98.8% UPLC purity) of the desired product (Cbz-Asn-Thr(tBu)-OMe).

[1418] Example I-2: Catalytic hydrogenolysis to obtain H-Asn-Thr(tBu)-OMe

[1419]

[1420] Cbz-Asn-Thr(tBu)-OMe (266.8 kg, 609.8 mol, 1.0 equiv) and 2-MeTHF (7.5 vol, 1981 L, 1704 kg) were added to a hydrogenation reactor. Wet Pd / C (26.75 kg, 10 wt%) was added and the atmosphere was switched to N2 three times, then to H2 three times. Hydrogen pressure (40 psi) was applied and the reaction mixture was stirred at 24°C to 27°C for 4 hours.

[1421] The mixture was filtered through a celite filter and the filter cake was washed with 2-MeTHF (2 volumes, 533 L, 458 kg). The product was transferred into solution by the addition of 4-methylbenzenesulfonic acid (117.6 kg, 609.8 mol, 1.0 equiv) in 2-MeTHF (1.0 volume, 260 L, 223 kg) to give 2916 kg of the desired product (H-Asn-Thr(tBu)-OMe) as a solution (90.4% yield, 89.9% HPLC purity).

[1422] Example I-3: Synthesis of Fmoc-Pen(Trt)-Asn-Thr(tBu)-OMe

[1423]

[1424] A 10,000 L glass reactor with an overhead stirrer was charged with Fmoc-Pen(Trt)-OH (348 kg, 551.9 mol, 1.03 equiv), 2-MeTHF (4 volumes, 1105 L, 950 kg) and the solution obtained in Example 2 (2916 kg, H-Asn-Thr(tBu)-Ome). The reaction mixture was stirred at 20° C. to 25° C. for 0.5 h, then N-ethyl-N-isopropylpropan-2-amide (228 kg, 1764.1 mol, 2.89 equiv) was added dropwise over 1 h. TBTU (201 kg, 626 mol, 1.02 equiv) was added portionwise over 3 h, then the reaction mixture was stirred at 20° C. to 25° C. for 20 h until the reaction was complete.

[1425] The reaction mixture was diluted with 5% aqueous NaHCO (4.1 volumes, 2270 kg), added dropwise over 2 hours at 21° C. to 23° C., then stirred for 1 hour at 20° C. to 25° C. and separated. The organic phase was washed with 5% aqueous NaHCO (4.1 volumes, 2276 kg) and then with process water (3.2 volumes, 1747 kg).

[1426] The organic phase was concentrated to 3 volumes (relative to Fmoc-Pen(Trt)-Asn-Thr(tBu)-OMe) at 40°C, 2-MeTHF (5 volumes, 2741 L, 2357 kg) was then added, and the mixture was concentrated again to 3 volumes, twice in total. The walls of the reaction flask were rinsed with 2-MeTHF (0.84 volumes, 460 L, 396 kg), and EtOH (12 volumes, 5643 L, 45000 kg) was added dropwise at 15°C to 25°C over 6 hours, and the mixture was then stirred for 3 hours. The solution was cooled to -1°C to 1°C for 5 hours, and then stirred for an additional 16 hours.

[1427] The resulting mixture was filtered and the filter cake was washed with a pre-cooled (0°C) EtOH / 2Me-THF 4:1 mixture (2 volumes, 1060 L, 858 kg) and dried at 40°C under reduced pressure and N2 flow for 35 hours to afford 464.5 kg (85.6% yield, 98.6% HPLC purity) of the desired product (Fmoc-Pen(Trt)-Asn-Thr(tBu)-OMe).

[1428] Example I-4: Synthesis of H-Pen(Trt)-Asn-Thr(tBu)-OMe

[1429]

[1430] A 12500 L reactor with an overhead stirrer was charged with Fmoc-Pen(Trt)-Asn-Thr(tBu)-OMe (431 kg, 479.4 mol, 1.0 equiv), acetonitrile (5.0 vol, 2168 L, 1704 kg) and dodecanethiol (291 kg, 1438.2 mol, 3.0 equiv). DBU (22.2 kg, 143.8 mol, 0.3 equiv) was added dropwise over 1 hour, and the reaction mixture was stirred at 15° C. to 25° C. for 8 hours until the reaction was complete.

[1431] The reaction mixture was allowed to stand for 2 hours and the lower layer was removed. N-heptane (5 volumes, 2167L, 1473kg) was added, the mixture was stirred at 20°C for 1 hour and allowed to stand for 2 hours. The mixture was separated and the upper layer was removed. N-heptane (5 volumes, 2160L, 1469kg) was added and the solution was stirred at 0°C for 1 hour, then allowed to stand for 2 hours. After separation, the upper layer was removed, and n-heptane (5 volumes, 2160L, 1469kg) was added to the lower layer, and the mixture was stirred at 0°C for 1 hour and allowed to stand for 2 hours. Further separation and removal of the upper layer gave a solution (97.2% yield) of the desired product (H-Pen (Trt) -Asn-Thr (tBu) -OMe).

[1432] Example I-5: Synthesis of Ac-Pen(Trt)-Asn-Thr(tBu)-OMe

[1433]

[1434] Process water (0.4 vol, 174 kg) was added to the solution from the previous step (H-Pen(Trt)-Asn-Thr(tBu)-Ome), followed by the dropwise addition of acetic anhydride (55.6 kg, 527.3 mol, 1.1 eq) over 2 hours at 0° C. The mixture was stirred for 1 hour to give 2370 kg of a solution of the desired product (Ac-Pen(Trt)-Asn-Thr(tBu)-Ome) (97.9% yield, 97.7% UPLC purity).

[1435] Example I-6: Synthesis of Ac-Pen(Trt)-Asn-Thr(tBu)-OH

[1436]

[1437] A 12500 L reactor with overhead stirring was charged with the solution from the previous step (Ac-Pen(Trt)-Asn-Thr(tBu)-OMe) diluted to homogeneity with MeCN / H2O and process water (6 volumes, 2074 L, 2074 kg) at 0° C. LiOH·H2O (51.8 kg, 1246 mol, 2.6 equiv) was added dropwise at -5° C. to 5° C. over 4 hours, and the mixture was then stirred at 0° C. for 15 hours.

[1438] At -5 ℃ to 5 ℃, reaction mixture is adjusted to pH 4.96 with 8.5% HCl aqueous solution (1.16 volumes, 339kg), and 2-MeTHF (8 volumes, 2924L, 2514kg) is added. Use 1.1% HCl aqueous solution (5.8 volumes, 1984kg) that pH is further adjusted to 2.34, and the mixture is stirred for 2 hours and then left standstill for 1 hour. After separation, collect the upper strata and add 2-MeTHF (5 volumes, 1490kg) to the lower layer, then stir for 2 hours and leave standstill for 1 hour. The mixture is separated again and all organic phases are collected. Add 23% NaCl aqueous solution (5 volumes, 1924kg) thereto, the mixture is stirred for 2 hours, left standstill for 2 hours, and removed the lower layer after separation.

[1439] The organic phase was concentrated to 3 volumes at 40°C, and then 2-MeTHF (4.5 volumes, 1451 L, 1248 kg) was added. This process was repeated four more times with the following volumes of 2-MeTHF: 1323 L, 1391 L, 1416 L, 1431 L. MeCN (0.1 volume, 38 L, 30 kg) was then added to the reaction mixture along with Ac-Pen(Trt)-Asn-Thr(tBu)-OH (1.62 kg), and the solution was stirred for 1 hour. More MeCN (12 volumes, 3931 L, 3090 kg) was added, and the reaction was stirred at 40°C for 2 hours, then at 0°C for 38 hours.

[1440] The resulting mixture was filtered and the filter cake was washed with 2-MeTFH / MeCN (1 / 270 1 L, 568 kg) and then dried under reduced pressure at 43° C. This process produced 320 kg (90.2% yield, 100% UPLC purity) of the desired product (Ac-Pen(Trt)-Asn-Thr(tBu)-OH).

[1441] Example I-7: Synthesis of Fmoc-Pen(Acm)-Tyr(2-Boc-ea)-OMe

[1442]

[1443] Fmoc-Pen(Acm)-OH (369 kg, 1.0 equiv), H-Tyr(2-Boc-ea)-OMe (298 kg, 1.05 equiv) and MeCN (12.5 vol, 4612 L) were added to a 15000 L reactor and the mixture was cooled to 0°C. N-Methylmorpholine (0.5 equiv) and Oxyma Pure (0.5 equiv) were added, followed by the addition of EDCI (1.1 equiv) in portions over 2 hours at 0°C to 5°C. The resulting mixture was stirred at 0°C for 16 to 20 hours until the reaction was complete. Fmoc-Pen(Acm)-Tyr(2-Boc-ea)-OMe (1.5 kg) was added, and the mixture was stirred at 0°C for 12 hours, then the mixture was warmed to 20°C over 1 hour, and the slurry was aged for an additional 4 hours. Water (12 volumes, 4612 L) was added dropwise to the mixture over 2 hours, and the solution was allowed to stand for 4 hours. The reaction mixture was filtered, and the filter cake was washed with MeCN / H2O (1:1 v / v). The wet cake was dried under reduced pressure in a vacuum oven at 45°C for 48 hours to give 561 kg (88% yield, 99.8% UPLC purity) of the desired product (Fmoc-Pen(Acm)-Tyr(2-Boc-ea)-OMe).

[1444] Example I-8: Synthesis of H-Pen(Acm)-Tyr(2-Boc-ea)-OMe

[1445]

[1446] Fmoc-Pen(Acm)-Tyr(2-Boc-ea)-OMe (558 kg, 1.0 equiv) was combined with MeCN (5 vol, 2760 L) in an 8000 L reactor, and the mixture was cooled to 0°C. Pre-cooled dodecanethiol (4.0 equiv) was added, followed by DBU (0.95 equiv), metered in over 1 hour. After 10 hours, the reaction mixture was washed with heptane (3 x 5 vol), then diluted with EtOAc (6 vol) and washed with 15% aqueous NHCl (3 vol) and 25% aqueous NaCl (1 vol), followed by 10% aqueous NaCl (3 vol). This yielded 371.7 kg (94% yield, 99.5% UPLC purity) of the desired product (H-Pen(Acm)-Tyr(2-Boc-ea)-OMe).

[1447] Example I-9: Synthesis of Fmoc-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe

[1448]

[1449] To a solution of H-Pen(Acm)-Tyr(2-Boc-ea)-OMe (371.7 kg) was added Fmoc-Lys(Ac)-OH (0.96 equivalents relative to Fmoc-Pen(Acm)-Tyr(2-Boc-ea)-OMe from Example 8) and the solution was cooled to 0° C. N-methylmorpholine (0.5 equivalents), ethylcyanoacetaldehyde-2-oxime (0.5 equivalents) and EDCI (1.1 equivalents) were added and the reaction mixture was stirred for 16 to 20 hours until the reaction was complete. At 0° C., the solution was washed twice with 5% aqueous NaHCO (2×6 volumes), then with NH Cl (3 volumes) and 10% aqueous NaCl (3 volumes). The solution was concentrated to 3 volumes, then MeCN (8 volumes) was added and the resulting solution was concentrated to 5 volumes to give 641.5 kg (100% yield, 96.7% UPLC purity) of the desired solution (Fmoc-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe).

[1450] Example I-10: Synthesis of H-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe

[1451]

[1452] To a solution of Fmoc-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe (640.5 kg, 1.0 equiv) at 20° C., diethylamine (1.5 equiv) and dodecanethiol (3 equiv) were added, and the lines were flushed with MeCN (1 volume). The resulting solution was stirred at 20° C. for 7 to 10 hours. The reaction mixture was washed three times with heptane (3.5 volumes) and concentrated to 2 volumes, followed by the addition of 2-MeTHF (4 volumes). 488 kg (100% yield, 97.2% UPLC purity) of the desired product (H-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe) was obtained.

[1453] Example I-11: Synthesis of Fmoc-Trp(7Me)-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe

[1454]

[1455] To a solution of H-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe (496 kg, 0.97 equiv) at 0° C. to 5° C., Fmoc-Trp(7Me)-OH (0.97 equiv), ethylcyanoacetaldehyde-2-oxime (0.5 equiv), and EDCI (1.3 equiv) were added, and the reaction was then rinsed with 2-MeTHF (1.2 vol). The resulting mixture was stirred for 10 hours, washed twice with 5% NaHCO (2×6 vol), then with NH4Cl (6 vol) and 10% aqueous NaCl (6 vol). The solution was concentrated to 3.5 vol (relative to H-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe), 2-MeTFH (8.6 vol) was added, and the solution was concentrated again to 3.5 vol. This operation was repeated until the water content (KF) reached below 0.3% and then further 2-MeTHF (3.5 vol) was added.

[1456] The solution was cooled to 5°C, 1 wt% Fmoc-Trp(7Me)-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe was added, and the mixture was stirred for 20 hours. MBTE (10.0 volumes relative to Fmoc-Trp(7Me)-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe) was metered in over 5 hours, and the mixture was stirred at 5°C for 4 hours and then at 20°C for 8 hours. The mixture was filtered, and the filter cake was washed with cold MeTFH / MTBE (2 volumes, 1:2 v / v) followed by MTBE (2 volumes). The resulting solid was dried at 25°C to yield 694 kg (87.7% yield, 99.0% UPLC purity) of the desired product (Fmoc-Trp(7Me)-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe).

[1457] Example I-12: Synthesis of Boc-3Pal-Sarc-NH2

[1458]

[1459] Boc-3Pal-OH (95.1 kg, 357.1 mol, 1.0 equiv), NMP (4.0 vol, 380 L, 390 kg) and H-Sarc-NH2·HCl (46.7 kg, 375 mol, 1.05 equiv) were added to a 3000 L reactor at 20°C to 30°C. N,N-diisopropylethylamine (114.1 kg, 892.8 mol, 2.5 equiv) was added dropwise over 20 minutes, followed by the addition of HATU (152.2 kg, 392.8 mol, 1.1 equiv) in portions over 3.5 hours. The mixture was stirred at 20°C to 30°C for 2 hours, then EtOAc (10 vol, 951 L, 856 kg) was added over 7 hours, the mixture temperature was adjusted to 10°C to 20°C over 1 hour, and then stirred for 7 hours. The resulting mixture was filtered, and the filter cake was washed with EtOAc (4 volumes, 280.4 L, 342.4 kg) and dried under reduced pressure at 45° C. for 20 hours to afford 111 kg (92% yield, 99.7% UPLC purity) of the desired product (Boc-3Pal-Sarc-NH 2 ).

[1460] Example I-13: Synthesis of Cbz-Glu(tBu)-Asn-H

[1461]

[1462] MeCN (6 volumes, 762 L, 602 kg), THF (4 volumes, 508 L, 452 kg), and Cbz-Glu(tBu)-OH (127 kg, 376.4 mol, 1.0 equiv) were added to a 5000 L reactor at 20 to 30 °C. The reactor was cooled to -15 to -5 °C, PivCl was added over 20 minutes, followed by N-methylmorpholine over 2.5 hours, and the reaction mixture was stirred for an additional 2 hours. L-Asn (74.6 kg, 564.6 mol, 1.5 equiv) and N,O-bis(trimethylsilyl)acetamide (153 kg, 752.8 mol, 2.0 equiv) were added over 3 hours, and the mixture was then warmed to 15 to 25 °C and stirred for 14 hours. Process water (20 kg, 1129.2 mol, 3.0 equiv) was added to quench the reaction, and the mixture was stirred for 2 hours.

[1463] After removing excess L-Asn by filtration, the filter cake was washed with MeCN (3 volumes, 381 L, 301 kg), and the filtrate was concentrated to 4 volumes under reduced pressure at below 45° C. MeCN (5 volumes, 635 L, 502 kg) was added and the mixture was concentrated again to 4 volumes, and the solution temperature was adjusted to 15° C. to 25° C. 5% aqueous NaHSO (2.5 volumes, 318 L, 318 kg) was added over 1 hour, followed by the product (Cbz-Glu(tBu)-Asn-H) (508 kg, 0.4 wt%). The mixture was stirred for 1 hour, and then further 5% NaHSO (9.5 volumes, 1207 L, 1207 kg) was added over 5 hours, and the mixture was stirred for 6 hours.

[1464] The suspension was filtered and the filter cake was washed with process water (4 volumes, 508 L, 508 kg), and MTBE (10 volumes, 1270 L, 953 kg) was added to the wet cake. The slurry was stirred for 4 hours and then filtered. The filter cake was washed with MTBE (5 volumes, 635 L, 470 kg) and dried under vacuum at 45° C. for 32 hours to give 141.9 kg (83.5% yield, 98.2% UPLC purity) of the desired product (Cbz-Glu(tBu)-Asn-H).

[1465] Example I-14: Synthesis of Cbz-Glu(tBu)-Asn-3Pal-Sarc-NH2

[1466]

[1467] Cbz-Glu(tBu)-Asn-H (137.8 kg, 305.3 mol, 1.25 equiv), H-3Pal-Sarc-NH2 (57.7 kg, 244.2 mol, 1.0 equiv), DMF (3.4 vol, 194 L, 185 kg), THF (15 vol, 866 L, 770 kg) and HOAt (33.2 kg, 244.2 mol, 1.0 equiv) were added to a 5000 L reactor at 20°C to 30°C. The reaction mixture was then adjusted to -15°C to -5°C and a solution of DABCO in THF and DMF (DABCO (98.2 kg, 854.7 mol, 3.5 eq) dissolved in THF (9 vol, 519 L, 462 kg) and DMF (2 vol, 115 L, 110 kg)) was added over 2 hours at below -8°C, followed by the addition of EDCI (70.2 kg, 366.3 mol, 1.5 eq) in portions over 2.5 hours.

[1468] The mixture was stirred at -15°C to -5°C for 18 hours, then 7% aqueous NaHCO₃ was added at 25°C until the pH of the mixture reached 5 to 6. The solution temperature was adjusted to 20°C to 30°C, DMF (8.7 vol, 504 L, 479 kg) was added, and the mixture was distilled under reduced pressure below 40°C to 23 vol. EtOH (14 vol, 818 L, 646 kg) was added, and the mixture was distilled again below 50°C to 23 vol, then the temperature was adjusted to 20°C to 30°C. EtOH (5 vol, 289 L, 228 kg) was added, and the mixture was distilled again below 50°C to 23 vol, then the temperature was adjusted to 20°C to 30°C, and EtOH (8.5 vol, 489 L, 387 kg) was added. The mixture was stirred at 45°C to 55°C for 1 hour, then the temperature was adjusted to 35°C to 45°C, the product (577 g, 1 wt%) was added, and the mixture was stirred for 3 hours. EtOH (34 volumes, 1957 L, 1546 kg) was added over 5 hours, and the mixture was then stirred at 35°C to 45°C for 2 hours. The temperature of the mixture was adjusted to 15°C to 25°C over 3 hours, and then stirred for 3 hours. The mixture was then warmed to 45°C to 55°C over 1.5 hours, stirred at this temperature for 8 hours, cooled to 15°C to 25°C over 3 hours, stirred at this temperature for 4 hours, then cooled to 5°C to 15°C over 3 hours, and stirred at this temperature for 10 hours.

[1469] The resulting suspension was filtered and the filter cake was washed with EtOH (5.6 vol, 328 L, 259 kg) and then dried under reduced pressure at 45° C. for 54 hours to afford 126.94 kg (77.5% yield, 100% UPLC purity) of the desired product (Cbz-Glu(tBu)-Asn-3Pal-Sarc-NH 2 ).

[1470] Example I-15: Synthesis of H-Glu(tBu)-Asn-3Pal-Sarc-NH2

[1471]

[1472] Cbz-Glu(tBu)-Asn-3Pal-Sarc-NH2 (119.9 kg, 189.3 mol, 1.0 equiv) was suspended in DMF (4 volumes, 480 L, 456 kg) and water (0.25 volumes, 30 L, 30 kg) at 20°C to 30°C. Pd / C (12 kg, 10 wt%) was then added, and the air in the system was exchanged three times with nitrogen by vacuum. The reactor was filled with hydrogen to 0.24 MPa under vacuum at 10°C to 20°C, and the reaction mixture was stirred at 10°C to 20°C for 19 hours. The reaction suspension was filtered and the filter cake was washed with a solution of DMF (1.5 vol, 180 L, 171 kg) in water (0.09 vol, 10.8 L, 10.8 kg) to give 661.6 kg of the desired product (H-Glu(tBu)-Asn-3Pal-Sarc-NH2) as a solution (94.4% yield, 98.0% UPLC purity).

[1473] Example I-16: Synthesis of Fmoc-2Nal-Gly(THP)-OH

[1474]

[1475] To a solution of Fmoc-2Nal-OH (100.1 kg, 228.8 mol, 1.0 equiv) was added MeCN (5 volumes, 500 L, 395 kg), DCM (7 volumes, 700 L, 931 kg), and N-formylmorpholine (790 g, 6.87 mol, 0.03 equiv) at 20° C. to 30° C. Oxalyl chloride (43.6 kg, 343.2 mol, 1.5 equiv) was added over 2 hours and the mixture was stirred for 2 hours before being vacuum distilled to 7 volumes at 25° C. to 35° C. MeCN (3 volumes, 300 L, 237 kg) was added to the reactor, the temperature was adjusted to 5° C. to 15° C., and H-Gly(THP)-OH (46.5 kg, 343.2 mol, 1.5 equiv) was added, followed by BSA (93 kg, 456.4 mol, 2 equiv) over 1 hour. At 20 ° C, the mixture was stirred for 16 hours and then quenched with 5% NaHSO4 aqueous solution (3.3 volumes, 330 L, 330 kg). The solution was vacuum distilled to 8.3 volumes at 35 ° C to 45 ° C, MeCN (5 volumes, 500 L, 395 kg) was added, and the mixture was distilled again to 8.3 volumes. MeCN (5 volumes, 500 L, 395 kg) was further added, the temperature was adjusted to 5 ° C to 15 ° C, and Fmoc-2Nal-Gly (THP) -OH (1 kg, 1 wt %) was added. The mixture was stirred for 8 hours, and then 5% NaHSO4 aqueous solution (11.7 volumes, 1170 L, 1170 kg) was added over 14 hours, and the solution was stirred for another 5 hours.

[1476] The suspension was filtered and the filter cake was washed with process water (2 volumes, 200 L, 200 kg) and then mixed with DCM (6 volumes, 600 L, 663 kg) at 20° C. to 30° C. for 5 hours. The suspension was filtered again and the filter cake was washed with DCM (1 volume, 100 L, 133 kg) and then dried under reduced pressure at 45° C. for 41 hours. This produced 106.4 kg (82% yield, 100% UPLC purity) of the desired product (Fmoc-2Nal-Gly(THP)-OH).

[1477] Example I-17: Synthesis of Fmoc-2Nal-Gly(THP)-Glu(tBu)-Asn-3Pal-Sarc-NH2

[1478]

[1479] Fmoc-2Nal-Gly(THP)-OH (95.9 kg, 178.8 mol, 1.0 eq) and H-Glu(tBu)-Asn-3Pal-Sarc-NH (106.0 kg, 187.8 mol, 1.2 eq) were suspended in 2-MeTHF (7 vols, 671 L, 577 kg) and MeCN (2 vols, 192 L, 153 kg) at 20 to 30° C. The mixture was cooled to 5 to 15° C., HOAt (12.2 kg, 89.4 mol, 0.5 eq) was added, EDCI (51.4 kg, 268.2 mol, 1.5 eq) was added over 1 hour, and the mixture was stirred for 10 hours. The reaction was quenched with 0.72 wt% aqueous HCl (5 volumes, 500 L, 500 1 g) to pH 3.0 and the mixture was stirred at 15 to 25 °C for 1 hour. MBTE (5 volumes, 480 L, 355 kg) was added and the mixture was stirred for 1 hour and then allowed to stand for 1 hour.

[1480] After separation, the aqueous layer was set aside and the organic layer was extracted with 0.72 wt% aqueous HCl (3 volumes, 288 L, 288 kg), stirred at 20° C. for 1 hour, allowed to stand for 1 hour, and then combined with the aqueous layer. The combined aqueous layers were washed three times with MTBE (5 volumes, 480 L, 355 kg), and then 2-MeTHF (5 volumes, 480 L, 413 kg) was added at 15° C. to 25° C. The pH of the resulting solution was adjusted to pH 6.2 with 7% aqueous NaHCO (3 volumes, 480 L, 480 kg), and then NaCl (2.5 volumes, 240 kg) was added, and the mixture was stirred for 1 hour and allowed to stand for 1 hour.

[1481] After further separation steps, the organic layer was set aside and the aqueous layer was extracted twice with 2-MeTHF (5 volumes, 480 L, 413 kg) and then combined with the organic layer. The combined organic layers were washed with 5% aqueous LiCl (5 volumes, 480 L, 480 kg) and then with 5% aqueous NaCl (5 volumes, 480 L, 480 kg). Fmoc-2Nal-Gly(THP)-Glu(tBu)-Asn-3Pal-Sarc-NH (1.9 kg, 2 wt%) and MeCN (20 volumes, 1918 L, 1515 kg) were added and the mixture was stirred at 20°C to 30°C for 3 hours and then distilled under reduced pressure below 40°C to 15 volumes. MeCN (15 volumes, 1439 L, 1136 kg) was added and the mixture was stirred at 35°C to 45°C for 2 hours and then adjusted to 15°C to 25°C over 4 hours and stirred for 15 hours.

[1482] The suspension was filtered and the filter cake was washed with MeCN (4 volumes, 384 L, 303 kg) and then dried under reduced pressure at 45° C. for 54 hours to afford 661.6 kg (80% to 82% yield, 99.85% UPLC purity) of the desired product (Fmoc-2Nal-Gly(THP)-Glu(tBu)-Asn-3Pal-Sarc-NH ).

[1483] Example I-18: Synthesis of H-Trp(7Me)-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe

[1484]

[1485] To a solution of Fmoc-Trp(7Me)-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe (59.31 kg, 1.0 equiv) was added MeCN (202.4 kg), followed by diethylamine (5.75 kg, 1.5 equiv) over 0.38 hours, and then MeCN (61.6 kg). The reactor temperature was adjusted to 35°C to 45°C over 0.82 hours, and the mixture was stirred at this temperature for 4 hours, then the temperature was adjusted to 15°C to 25°C over 1.3 hours. Dodecan-1-thiol (31.79 kg, 3.0 equiv) was added over 0.62 hours, and the mixture was stirred for 4 hours, then n-heptane (1.5 volumes, 62.0 kg) was added and stirred for 1 hour. The reaction mixture was allowed to stand for 40 minutes, and after separation, the n-heptane phase was discarded and the MeCN phase was transferred back to the reaction. The addition of n-heptane, followed by stirring, settling, and separation was repeated three more times, and then the MeCN phase was concentrated to 3.5 volumes over 3.7 hours. 2-MeTHF (12.0 volumes, 712.2 kg) was added, and the solution was concentrated to 3.5 volumes over 6.3 hours, and then additional 2-MeTHF (4.0 volumes, 201.8 kg) was added to give 402 kg (107.1% yield, 95.0% UPLC purity) of a solution containing the desired product (H-Trp(7Me)-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe).

[1486] Example I-19: Ac-Pen(Trt)-Asn-Thr(tBu)-Trp(7Me)-Lys(Ac)-Pen(Acm)-Tyr(2- Synthesis of Boc-ea)-OMe

[1487]

[1488] A 3000 L reactor was charged with a solution of Ac-Pen(Trt)-Asn-Thr(tBu)-OH (37.06 kg, 1.0 equiv), H-Trp(7Me)-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe in 2-MeTHF (401.6 kg, 1.0 equiv), 2-MeTHF (14.0 kg), and process water (21.0 kg), followed by anhydrous Oxyma B (5.5 kg, 0.56 equiv) and 2-MeTHF (54.0 kg). The temperature was adjusted to 10° C. to 20° C., N,N′-diisopropylcarbodiimide (10.0 kg, 1.5 equiv) was added dropwise, and the mixture was stirred for 10 hours. 2M HCl (1.2 volumes, 56.2 kg) was then added over a period of 1 hour, the mixture was stirred for 1 hour, and then a 5% aqueous NaHCO solution (5.5 volumes, 262.8 kg) was added over a period of 1 hour. The temperature of the reactor was adjusted to 20° C. to 30° C., the mixture was stirred for 1 hour, allowed to stand for 1 hour, and after separation, the aqueous phase was discarded, and the washing steps were repeated for the remaining organic phase. 20% aqueous NaCl solution (6.5 volumes, 309.2 kg) was added over a period of 1 hour at 10° C. to 20° C., the temperature was then adjusted to 20° C. to 30° C., the mixture was stirred, allowed to stand, separated, and the aqueous phase was discarded. The mixture was concentrated under reduced pressure below 40° C. to 6.5 to 7.5 volumes, and then a 17% H 2 O / THF solution (9.5 volumes, 453.8 kg) was added. The mixture was stirred at 20 to 30° C. for 1 hour to give 776.4 kg (103.9% yield, 90.2% UPLC purity) of the desired product as a H 2 O / THF solution (Ac-Pen(Trt)-Asn-Thr(tBu)-Trp(7Me)-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe).

[1489] Example I-20: Ac-Pen(Trt)-Asn-Thr(tBu)-Trp(7Me)-Lys(Ac)-Pen(Acm)-Tyr(2- Synthesis of Boc-ea)-OH-straight chain

[1490]

[1491] Ac-Pen(Trt)-Asn-Thr(tBu)-Trp(7Me)-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe in H2O / THF (776.4 kg, 1.0 eq) and water (2.53 vol, 211.5 kg) was charged to a 3000 L reactor at room temperature. The temperature was adjusted to 0°C to 10°C, and a solution of NaOH (1.5 eq, 3.15 kg) in water (0.47 vol, 39.3 kg) was added dropwise over 30 minutes, and the mixture was stirred for 5 hours. 2M HCl (53.4 kg) was added, the mixture was warmed to 15°C to 25°C, and NaCl (0.27 vol, 22.6 kg) was added. After separation, the organic phase was concentrated to 3 vol under reduced pressure below 35°C. 10% process water in acetonitrile (3.5 vol, 296 kg) was added and the mixture was concentrated to 3 vol at below 35° C. and this process was repeated two more times. 10% process water in acetonitrile (4.5 vol, 390 kg) was added to obtain 645.8 kg (97.3% yield, 89.9% UPLC purity) of the desired product (Ac-Pen(Trt)-Asn-Thr(tBu)-Trp(7Me)-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OH-linear) in solution.

[1492] Example I-21: Ac-Pen(Trt)-Asn-Thr(tBu)-Trp(7Me)-Lys(Ac)-Pen(Acm)-Tyr(2- Synthesis of Boc-ea)-OH-ring

[1493]

[1494] The Ac-Pen(Trt)-Asn-Thr(tBu)-Trp(7Me)-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OH-linear solution prepared in Example 20 (645.4 kg, 1.0 equiv) was mixed with 2,6-lutidine (12.4 kg, 2.25 equiv) and process water (0.47 vol, 38.0 kg) in a 2000 L reactor. MeCN (10.0 vol, 807 L, 634 kg), process water (4.3 vol, 355 L, 355 kg), diiodine (29.1 kg, 0.9 equiv), KI (19.05 kg, 2.25 equiv) and formic acid (2.1 kg, 0.9 equiv) were added to the 3000 L reactor and the temperature was adjusted to 20° C. to 30° C. In 10.5 hours, the solution from 2000L reactor was dropwise added into 3000L reactor, and the mixture was stirred for 2 hours.Add 7% NaHCO the aqueous solution (0.1 volume, 8kg), use 15.2% Na s o (1.5 volumes, 122kg) cancellation reaction, then add NaCl (1.0 volumes, 81kg).Mixture was stirred for 2 hours, left standstill 1 hour, after separation, remove water layer.Organic layer is lower than 35 ℃ of vacuum concentrations to 3.5 volumes, then add 44% MeCN aqueous solution (1.13 volumes, 91.4kg) and EtOAc (3.9 volumes, 317.8L, 286kg), the mixture was stirred for 5 hours, left standstill 30 minutes and separated, again discard water.Add 10% NaCl aqueous solution (1.92 volumes, 154.6kg), the mixture was stirred 30 minutes, left standstill 30 minutes, separated, and removed water.

[1495] The organic layer was concentrated to give 414.0 kg of a solution with a water content (KF) of 5.7 wt % and a final product (Ac-Pen(Trt)-Asn-Thr(tBu)-Trp(7Me)-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OH-ring) of 9.2 wt %. MeCN (83.0 L, 65.2 kg) and EtOAc (1.1 L, 1.0 kg) were added along with 0.31% of the product (0.25 kg), and the mixture was stirred for 17 hours. EtOAc (928.1 L, 835.2 kg) was then added dropwise over 4 hours. The solution was cooled to 15° C. to 25° C. over 1 hour and then stirred at this temperature for 20 hours.

[1496] After filtration, the filter cake was washed with MeCN / EtOAc / H2O (ratio: 2.82 / 17.7 / 0.51 v / v / v) (1 volume, 81.4 kg) and washed with EtOAc (0.9 volume, 70.4 kg), and then dried at 20°C to 30°C for 23 hours to obtain 55.75 kg (75.1% yield, 97.1% UPLC purity) of the desired product (Ac-Pen(Trt)-Asn-Thr(tBu)-Trp(7Me)-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OH-ring) as a solid.

[1497] Example I-22: Synthesis of H-2Nal-Gly(THP)-Glu(tBu)-Asn-3Pal-Sarc-NH2

[1498]

[1499] Fmoc-2Nal-Gly(THP)-Glu(tBu)-Asn-3Pal-Sarc-NH2 (42.03 kg, 1.0 equiv) was dissolved in THF (7.86 vol, 296.2 kg) at room temperature. Dihexylamine (8.80 kg, 1.22 equiv), THF (2.32 vol, 85.8 kg) and process water (1.14 vol, 48.0 kg) were added to the solution, and the mixture was stirred at 35°C to 45°C for 16 hours. The reactor was cooled to 15°C to 25°C, n-heptane (3.40 vol, 97.2 kg) and process water (1.69 vol, 71.0 kg) were added, and the phases were separated. The aqueous phase was extracted with n-heptane (3.40 vol, 97.2 kg) and the resulting solution was separated again and the organic layers were combined to give 172.8 kg (99.3% yield, 99.2% HPLC purity) of the desired product (H-2Nal-Gly(THP)-Glu(tBu)-Asn-3Pal-Sarc-NH2) as a solution.

[1500] Example I-23: Ac-Pen-Asn-Thr(tBu)-Trp(7Me)-Lys(Ac)-Pen-Tyr(2-Boc-ea)- Synthesis of 2Nal-Gly(THP)-Glu(tBu)-Asn-3Pal-Sarc-NH2

[1501]

[1502] In a 2000 L reactor, Ac-Pen(Trt)-Asn-Thr(tBu)-Trp(7Me)-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OH-ring (46.5 kg, 1.0 equiv) and H-2Nal-Gly(THP)-Glu(tBu)-Asn-3Pal-Sarc-NH2 solution from the previous step (172.2 kg, 1.05 equiv) were mixed with THF (4 volumes, 186 L, 165.5 kg). Anhydrous Oxyma B (3.40 kg, 0.5 equiv) was added at 20° C. to 25° C., while N,N'-diisopropylcarbodiimide (6.95 kg, 1.5 equiv) was added dropwise over 30 minutes, and the mixture was then stirred for 5 hours. The mixture was cooled to 10°C to 20°C, 2M HCl (18.6 kg) was added, and the mixture was stirred for 1 hour, then 5% aqueous NaHCO solution (62.0 kg) was added and the mixture was stirred for 30 minutes. 2-MeTHF (4.1 volumes, 189.4 kg) was added, and the mixture was stirred for 30 minutes, allowed to stand for 1 hour, and the aqueous phase was removed. 5% aqueous NaHCO solution (62.0 kg) was added, the mixture was stirred for 1 hour, allowed to stand for 1 hour, and after separation, the aqueous phase was removed. As a final washing step, 5% aqueous NaCl solution (42.4 kg) was added, the mixture was stirred for 1 hour, allowed to stand for 1 hour, and after separation, the aqueous phase was removed.

[1503] The organic phase was concentrated under vacuum to 2 to 3 volumes at below 40°C, then IPA (5 volumes, 290 kg) was added and the concentration step was repeated, with the IPA and concentration steps being performed twice in total. IPA (1.5 volumes, 90.0 kg) was added at 30°C, followed by additional IPA (1.1 volumes, 67.2 kg) at 35°C, while process water (10 volumes, 765 kg) was added over 1.5 hours. The product (Ac-Pen(Trt)-Asn-Thr(tBu)-Trp(7Me)-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-2Nal-Gly(THP)-Glu(tBu)-Asn-3Pal-Sarc-NH2) (0.276 kg, 0.3 wt%) was added, and the mixture was stirred for 4 hours, then cooled to 20°C over 10 hours and stirred for an additional 6 hours.

[1504] After filtration, the filter cake was washed with 28% aqueous IPA (2.7 vol, 206 kg) and EtOAc (0.9 vol, 70 kg), and then dried at 40°C to 45°C for 4 days to afford two batches (1.30.0 kg, 37.9% yield, 99.1% UPLC purity, and 2.40.93 kg, 51.4% yield, 99.3% UPLC purity) of the desired product (Ac-Pen(Trt)-Asn-Thr(tBu)-Trp(7Me)-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-2Nal-Gly(THP)-Glu(tBu)-Asn-3Pal-Sarc-NH2) as a solid.

[1505] Example I-24: Ac-Pen-Asn-Thr-Trp(7Me)-Lys(Ac)-Pen-Tyr(2-ea)-2Nal-Gly Synthesis of (THP)-Glu-Asn-3Pal-Sarc-NH2

[1506]

[1507] Ac-Pen-Asn-Thr(tBu)-Trp(7Me)-Lys(Ac)-Pen-Tyr(2-Boc-ea)-2Nal-Gly(THP)-Glu(tBu)-Asn-3Pal-Sarc-NH2 (both batches) were charged to a 3000 L reactor and AcOH (3.6 vol, 262 kg) and process water (0.15 vol, 10 kg) were added at 25° C. The mixture was stirred until a clear solution was obtained and the temperature was then adjusted to 15° C. In a separate reactor, AcOH (1.65 vol, 119 kg) and acetyl chloride (61 kg, 24 eq) were added and cooled to 10°C, followed by the addition of 18.9% (H2O / AcOH) solution (1.4 vol, 93.5 kg) over 2 hours, and then the initial Ac-Pen(Trt)-Asn-Thr(tBu)-Trp(7Me)-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-2Nal-Gly(THP)-Glu(tBu)-Asn-3Pal-Sarc-NH2 mixture was added to the reactor over 1.2 hours. The lines were flushed with AcOH (0.32 vol, 22 kg) and the mixture was stirred for 1 hour, then 19.4% aqueous NaOH (14.6 vol, 1000 kg) was added over 6 hours, followed by the product (Ac-Pen-Asn-Thr-Trp(7Me)-Lys(Ac)-Pen-Tyr(2-ea)-2Nal-Gly(THP)-Glu-Asn-3Pal-Sarc-NH2) (0.21 kg, 0.3 wt%). The mixture was stirred at 20°C for 2 hours, then the pH was adjusted by adding 19.4% aqueous NaOH (2.3 vol, 160 kg) and then stirred for 16 hours.

[1508] The mixture was filtered and the filter cake was washed with process water (4.1 vol, 280 kg) and EtOAc (1.8 vol, 125 kg), then dried under vacuum at 40°C to 45°C for 16 hours to afford 56.1 kg (84.4% yield, 97.8% UPLC purity) of the desired product (Ac-Pen-Asn-Thr-Trp(7Me)-Lys(Ac)-Pen-Tyr(2-ea)-2Nal-Gly(THP)-Glu-Asn-3Pal-Sarc-NH2).

[1509] Example 1-25: Synthesis of H-3Pal-Sarc-NH2 (Alternative to Example 14)

[1510]

[1511] MeCN (8 volumes, 696 L, 687 kg) and 4M HCl in EtOAc (765.6 kg, 3103.2 mol, 12 equiv) were added to a 5000 L reactor at 20° C. to 30° C., and the mixture was stirred for 1 hour. Boc-3Pal-Sarc-NH (87 kg, 258.6 mol, 1.0 equiv) was added in ten portions over 7 hours, and the mixture was stirred for 3 hours. The suspension was filtered, and the filter cake was washed with MeCN (4 volumes, 348 L, 278 kg) and dried under vacuum at 25° C. for 22 hours to give 92.8 kg (98.2% yield, 99.6% UPLC purity) of the desired product (H-3Pal-Sarc-NH).

[1512] The following reaction schemes may aid in understanding the reactions discussed throughout the following examples.

[1513] Reaction Scheme II

[1514]

[1515] Example II-1: Synthesis of H-Lys(Ac)-Asn-D-Leu-NH2(H-FG3-NH2)

[1516]

[1517] Example II-1a: Synthesis of Z-Asn-D-Leu-NH2

[1518]

[1519] In a 10 L reactor, Z-Asn-OH (150.0 g; 1.0 equivalent), (80.1 g; 1.0 eq) and HD-Leu-NH2*HCl (98.6 g; 1.05 eq) were dissolved in DMF (1.8 L) and cooled to 0°C to 5°C. TEA (172 mL; 2.2 eq) was added to the mixture, followed by EDC*HCl (3 x 40.5 g; 1.13 eq) in three portions over 1 hour. The yellow reaction mixture was stirred at 0°C to 5°C for 1 hour and then allowed to warm to room temperature. After stirring for an additional hour, the mixture was poured into 2% aqueous NaHCO3 (15 L) to precipitate. The resulting yellow suspension was stirred for several minutes and then filtered. The filter cake was washed with water (6 x 750 mL) and EtOAc (6 x 600 mL). The product was dried in a vacuum oven at reduced pressure at 30°C over the weekend to give 188 g of white solid Z-Asn-D-Leu-NH2 (88% yield, ESI-MS m / z 379.16 ([M+H] + )).

[1520] Example II-1b: Synthesis of Asn-D-Leu-NH2

[1521]

[1522] Z-Asn-D-Leu-NH2 (230 g, 1.0 equivalent) and Pd / C 5% (23 g) were suspended in MeOH / H2O (95:5, 4.6 L), followed by the addition of HCl 36% (57 mL, 1.1 equivalents). The reaction mixture was stirred at room temperature for 3 h under 3.0 bar H2 pressure. After the reaction was complete, the hydrogenated solution was clarified and filtered, and the filter was washed with MeOH (2 × 200 mL). The filtrate was evaporated under reduced pressure at 40 ° C, and the remaining oil was co-distilled with EtOH (3 × 2.5 L). EtOH (2.5 L) was added to the remaining oil, and the solution was stirred at 10 ° C for 1 hour. IPE (5.75 L) was added to the formed suspension, and the mixture was stirred at room temperature for 30 minutes. The suspension was filtered, and the filter cake was washed with IPE (3 × 575 mL). The product was dried in a vacuum oven at 40° C. for 18 hours to obtain 169 g of white solid Asn-D-Leu-NH 2 (yield: 99%, ESI-MS: m / z=415.36 [M+H + ] + ).

[1523] Example II-1c: Synthesis of Z-Lys(Ac)-Asn-D-Leu-NH2

[1524]

[1525] H-Asn-D-Leu-NH2.HCl (140.0 g, 1.0 equiv) and Z-Lys(Ac)-OH (160.7 g, 1.0 equiv) were suspended in DMF (2.8 L). The dilute white suspension was cooled to 0°C to 5°C, and DIPEA (261 mL, 3.0 equiv) was added to the reaction mixture. TBTU (168 g, 1.05 equiv) was added in one portion, and the yellow reaction mixture was stirred at 0°C to 5°C for 30 minutes, then warmed to room temperature and stirred for an additional hour. The mixture was poured into 2% aqueous NaHCO3 (17 L) to precipitate, and the resulting suspension was stirred at 10°C for 2.5 hours. The suspension was filtered, and the filter cake was washed with 2% NaHCO3 (3 x 300 mL) and water (3 x 300 mL). The product was dried in a vacuum oven at 50° C. for 3 days to obtain 132.0 g of white solid Z-Lys(Ac)-Asn-D-Leu-NH 2 (yield: 48% ESI-MS m / z=549.33 [M+H] + ).

[1526] Example II-1d: Synthesis of H-Lys(Ac)-Asn-D-Leu-NH2

[1527]

[1528] Z-Lys(Ac)-Asn-D-Leu-NH2 (153g, 1.0 equivalent) and Pd / C 5% (15.3g) were suspended in a MeOH / water mixture (5:1, 2.22L). The suspension was then hydrogenated at room temperature under 3.5 bar H2 pressure. After 4 hours, the reaction conversion rate only reached 50%. The suspension was filtered and the filtrate was stored at 0°C to 5°C overnight. Fresh Pd / C 5% (15.3g) was added to the filtrate, and the suspension was hydrogenated at 40°C under 3.5 bar H2 pressure for 4 hours. The reaction mixture was then filtered and the filter was washed with MeOH (3×100mL). The filtrate was concentrated under reduced pressure at 50°C, and the residue was co-distilled with EtOH (4×1000mL) to obtain 700g of residue. The oil was diluted with EtOAc (3L) and the resulting white suspension was stirred at room temperature for 30 minutes. The suspension was filtered and washed with EtOAc (3×400 mL). The product was dried in a vacuum oven at 30°C for 2 days to obtain 105.7 g of white solid H-Lys(Ac)-Asn-D-Leu-NH2. (Yield 91%, ESI-MS m / z=415.36 [M+H]) + ).

[1529] Example II-2: Synthesis of Fmoc-2-Nal-αMe-Lys(Boc)-OH (Fmoc-FG2-OH)

[1530]

[1531] PyAOP (65.5 g, 1.1 equivalents) was dissolved in Me-THF / DMSO (5:1, 1.2 L) and cooled to 0 to 5 ° C with an ice bath. DIPEA (40 mL, 2.0 equivalents) and Fmoc-2-Nal-OH (50 g, 1.0 equivalents) were added, and the yellow suspension was stirred at 0 to 5 ° C for 15 minutes. H-αMeLys(Boc)-OH (35.7, 1.2 equivalents) was added once, and the reaction mixture was stirred at room temperature for 2 hours. The reaction mixture was diluted with MeTHF (1000 mL) and washed with 5% NaHCO3 (1×1000 mL). The organic layer was then washed with 2% NaHCO3 / DMSO (7:3, 9×800 mL) and 2% NaCl (2×800 mL). The organic layer was concentrated under reduced pressure at 40 ° C, and the oil was co-distilled with MeTHF (2×500 mL). The light yellow oil was dissolved in MeTHF / IPE (1:2, 600mL) and poured into pentane (2L). The suspension was stirred at room temperature for 15 minutes, then filtered, and the filter cake was washed with pentane / IPE 7:1 (2×400mL). The product was dried at 40°C for 18 hours in a vacuum oven. The dried material was suspended in IPE (1.1L) and stirred at room temperature for 1 hour. The white suspension was filtered and washed with IPE (2×250mL). The product was dried at 40°C for 16 hours in a vacuum oven, then suspended in IPE (2000mL) and stirred at room temperature. After 4 hours, the off-white suspension was filtered, and the filter cake was washed with IPE (2×200mL). The product was dried at 40°C for 18 hours in a vacuum oven. This step was repeated a second time to isolate the white solid product Fmoc-2-Nal-αMe-Lys(Boc)-OH(Fmoc-FG2-OH) (156 g). (Yield 72.2 g, 92%, ESI-MS m / z=680.17 [M+H] + ).

[1532] Example II-3: Synthesis of 2Nal-αMe-Lys(Boc)-Lys(Ac)-Asn-D-Leu-NH2(H-FG2+3-NH2)

[1533]

[1534] Example II-3a: Fmoc-2Nal-αMe-Lys(Boc)-Lys(Ac)-Asn-D-Leu-NH2(Fmoc-FG2+3- Synthesis of NH2)

[1535]

[1536] Fmoc-2-αMeLys(Ac)-OH (113.0 g, 1.0 equivalent) was dissolved in MeTHF / DMSO (4:1, 1700 mL), and the solution was cooled to 0°C to 5°C. H-Lys(Ac)-Asn-D-Leu-NH2 (82.7 g, 1.2 equivalents) and PyAOP (95.3 g, 1.1 equivalents) were added to the reaction mixture in one go, followed by DIPEA (57.9 mL, 2.0 equivalents). The ice bath was then removed, the reaction was allowed to warm to room temperature and stirred overnight (17 hours). The reaction mixture was then washed with 5% NaHCO3 (2×3400 mL) and 2% NaHCO3 (2×2300 mL). The organic layer was filtered and the filtrate was evaporated under reduced pressure at 50°C. The residue was co-distilled with EtOAc (2×700 mL), and the resulting suspension was diluted with EtOAc (800 mL) and stirred at 50° C. for 10 minutes, then at room temperature for 30 minutes. The suspension was filtered, and the filter cake was washed with EtOAc (3×380 mL). The product was dried under vacuum at 40° C. for 18 hours to give 137 g of the desired product as a white solid, 2Nal-αMe-Lys(Boc)-Lys(Ac)-Asn-D-Leu-NH2(H-FG2+3-NH2) (yield 77%, ESI-MS m / z=1077.47 [M+H] + ).

[1537] Example II-3b: H-2Nal-αMe-Lys(Boc)-Lys(Ac)-Asn-D-Leu-NH2(H-FG2+3-NH2) synthesis

[1538]

[1539] Fmoc-2-αMeLys(Ac)-OH (113.0 g, 1.0 equivalent) was dissolved in MeTHF / DMSO (4:1, 1700 mL), and the solution was cooled to 0°C to 5°C. H-Lys(Ac)-Asn-D-Leu-NH2 (82.7 g, 1.2 equivalents) and PyAOP (95.3 g, 1.1 equivalents) were added to the reaction mixture in one go, followed by DIPEA (57.9 mL, 2.0 equivalents). The ice bath was then removed, the reaction was allowed to warm to room temperature and stirred overnight (17 hours). The reaction mixture was then washed with 5% NaHCO3 (2×3400 mL) and 2% NaHCO3 (2×2300 mL). The organic layer was filtered and the filtrate was evaporated under reduced pressure at 50°C. The residue was co-distilled with EtOAc (2×700 mL), and the resulting suspension was diluted with EtOAc (800 mL) and stirred at 50° C. for 10 minutes, then at room temperature for 30 minutes. The suspension was filtered, and the filter cake was washed with EtOAc (3×380 mL). The product was dried under vacuum at 40° C. for 18 hours to give 137 g of the desired product as a white solid, H-2Nal-αMe-Lys(Boc)-Lys(Ac)-Asn-D-Leu-NH2(H-FG2+3-NH2). (Yield 96%, ESI-MS m / z=854.48 [M+H]) + ).

[1540] Example II-4: Synthesis of Ac-Pen(Trt)-Asn-Thr(tBu)-OH (FG1 tripeptide)

[1541] Example II-4a: Synthesis of Z-Asn-Thr(tBu)-Ome

[1542]

[1543] To a solution of Z-Asn-OH (500.00 g, 1.877 mol, 1.0 equiv), H-Thr(tBu)-OMe (445.06 g, 1.971 mol, 1.05 equiv) and Oxyma Pure (266.85 g, 1.877 mol, 1.0 equiv) in EtOAc:DMSO (1:1, v:v) (3 L) was added triethylamine (572.6 mL, 4.311 mol, 2.2 equiv) and the mixture was stirred at 25° C. to 30° C. for 10 minutes. EDC x HCl (468.00 g, 2.441 mol, 1.3 equiv) was added to the reaction mixture in four portions over 1 hour and stirred overnight. IPC-HPLC showed the reaction was complete.

[1544] The reaction mixture was diluted with EtOAc (6 L) and washed with NaHSO4 (5% aqueous solution) (2×5 L), NaHCO3 (5% aqueous solution) (4×5 L) and water (5 L). The organic layer was evaporated under reduced pressure at 40°C (AT) and the residue was co-evaporated with EtOAc (3×3 L). The residue (about 25% w / v) was cooled to 20°C and seeded with crystals. The product crystallized and the resulting suspension was stirred at 0°C to 5°C for 2 hours before the product was isolated by filtration. The filter cake was washed with pre-cooled EtOAc (3×1 L) and the product was dried under reduced pressure at 30°C overnight to give 653 g of white solid Z-Asn-Thr(tBu)-OMe (yield 80%, ESI-MS m / z 438.18 [M+H] + ).

[1545] Example II-4b: Synthesis of Fmoc-Pen(Trt)-Asn-Thr(tBu)-OMe

[1546]

[1547] Z-Asn-Thr(tBu)-OMe (330.0 g, 0.754 mol, 1.0 equiv) and EtOAc (2.6 L) were charged into a hydrogenation reactor and the mixture was stirred until a clear solution was obtained. Pd(OH)2 on activated carbon (6.6 g, 2% (w:w)) was added to the reaction mixture, the reactor was closed, inerted with nitrogen, and the temperature was set at 40°C. Hydrogen pressure (3 bar) was applied and the reaction mixture was stirred under this condition. IPC-HPLC after 5 hours showed a quantitative reaction. The reaction mixture was cooled to 25°C and filtered through a depth filter to remove the catalyst and stored at 4°C overnight (mass: 2.46 kg). The concentration of H-Asn-Thr(tBu)-OMe was calculated using a non-qualified standard of H-Asn-Thr(tBu)-OMe, and the required amount of solution was taken directly to the next step without isolating the intermediate.

[1548] A 15 L glass reactor with an overhead stirrer was charged with Fmoc-Pen(Trt)-OH (387.0 g, 0.628 mol, 1.0 equiv), TBTU (216.2 g, 0.673 mol, 1.07 equiv), DMSO (0.6 L) and the solution obtained in the above step (2.3 kg, 200.0 g H-Asn-Thr(tBu)-OMe, 0.659 mol, 1.05 equiv). The reaction mixture was stirred at 22 ° C until a clear solution was formed, and DIPEA (305.2 mL, 1.795 mol, 2.0 equiv) was immediately added. The reaction mixture was stirred at 20 ° C to 25 ° C. IPC-HPLC after 1 hour showed that the reaction was complete.

[1549] At this time, the reaction mixture was diluted with EtOAc (2.0 L) and washed with NaHCO3 (5% aqueous solution) (3×3 L) and water (2×3 L). The solvent of the organic phase was evaporated under reduced pressure at 35°C, and the residue was co-evaporated with EtOAc (2×2.5 L). The residue was placed in EtOAc (3.0 L) and the product was precipitated by slowly adding the product solution to heptane (30 L). The formed white suspension was stirred at 20°C to 25°C for 30 minutes, and then the product was isolated by filtration. The filter cake was washed with heptane (2×2 L) and dried under vacuum at 35°C for 18 hours to give 545 g of the desired product as a white solid Fmoc-Pen(Trt)-Asn-Thr(tBu)-OMe. (HPLC-purity: 98.7%, yield 96.5%)

[1550] Example II-4c: Synthesis of H-Pen(Trt)-Asn-Thr(tBu)-Ome

[1551]

[1552] A 15 L glass reactor with an overhead stirrer was charged with Fmoc-Pen(Trt)-Asn-Thr(tBu)-OMe (500.0 g, 0.556 mol, 1.0 eq) and EtOAc:DMSO (9:1, v:v) (5.0 L). The reaction mixture was stirred at 22 ° C until a clear solution was formed. DBU (24.9 mL, 0.167 mol, 0.3 eq) was added and the reaction mixture was stirred at 20 ° C to 25 ° C. IPC-HPLC after 90 minutes showed that the reaction was complete.

[1553] At this time, the reaction mixture was diluted with EtOAc (4.0 L) and washed with NaHCO3 (5% aqueous solution) (4 L) and water (4 L). The solvent of the organic phase was evaporated under reduced pressure at 40°C and the residue was co-evaporated with EtOAc (2 x 2.0 L).

[1554] The residue was taken up in EtOAc (2.0 L) and the product was precipitated by slowly adding the product solution to heptane (30 L). The resulting white suspension was stirred at 20°C to 25°C for 15 minutes, and then the product was isolated by filtration. The filter cake was washed with heptane (2 x 2 L) and dried under vacuum at 35°C for 18 hours to give 337 g of the desired product as a white solid, H-Pen(Trt)-Asn-Thr(tBu)-OMe. (Yield 89.5%).

[1555] Example II-4d: Synthesis of Ac-Pen(Trt)-Asn-Thr(tBu)-OMe

[1556]

[1557] A 15 L glass reactor with an overhead stirrer was charged with H-Pen(Trt)-Asn-Thr(tBu)-OMe (318.2 g, 0.470 mol, 1.0 eq) and MeOH (3.0 L), and the reaction mixture was stirred at 22° C. until a clear solution formed. Acetic anhydride (55.6 mL, 0.588 mol, 1.25 eq) was added, and the reaction mixture was stirred at 20° C. to 25° C. IPC-HPLC after 1 hour indicated the reaction was complete.

[1558] At this time, the reaction mixture was concentrated to a final volume of 0.4 L by evaporation of the solvent at 45° C., and the residue was taken up in EtOAc:Me-THF (1:1, v:v) (4.0 L). The organic phase was washed with NaHCO (5% aqueous solution) (2 L) and water (2 L), and the solvent of the organic phase was evaporated under reduced pressure at 45° C. (AT), and the residue was co-evaporated with EtOAc (2×1.5 L).

[1559] The residue was taken up in EtOAc (3.0 L) and the product was precipitated by slowly adding the product solution to heptane (30 L). The resulting white suspension was stirred at 20° C. to 25° C. for 15 minutes, and then the product was isolated by filtration. The filter cake was washed with heptane (4×1 L) and dried under vacuum at 35° C. for 18 hours to give 328.2 g of the desired product as a white solid, Ac-Pen(Trt)-Asn-Thr(tBu)-OMe.

[1560] (Yield 97.1%)

[1561] Example II-4e: Synthesis of Ac-Pen(Trt)-Asn-Thr(tBu)-OH (FG1 tripeptide)

[1562]

[1563] A 10 L reactor with overhead stirring was charged with Ac-Pen(Trt)-Asn-Thr(tBu)-OMe (310.0 g, 0.431 mol, 1.0 eq) and THF (1.5 L). The mixture was stirred until a clear solution was obtained. The product solution was diluted with water (1.5 L) and cooled to 5 ° C. A solution of LiOH x H2O (25.35 g, 0.603 mol, 1.4 eq) in water (0.5 L) was added to the reaction mixture over 90 minutes while stirring at 5 ° C. IPC-HPLC after 5 hours showed almost complete reaction (SM:

[1564] 1.2%).

[1565] At this time, the reaction mixture was diluted with water (1.5 L) and Me-THF (5 L), and the layers were separated (the product remained in the aqueous phase). Me-THF (6 L) was added to the aqueous phase, and the pH of the two-phase mixture was adjusted to 4.7 with HCl (10%, approximately 100 mL). The phases were separated and the aqueous phase was re-extracted with EtOAc (3.0 L). The two organic phases were combined and the solvent was evaporated under reduced pressure at 35° C. (AT), followed by co-evaporation of the residue with EtOAc (2×3.0 L).

[1566] The residue was taken up in EtOAc (3.0 L) and the product was precipitated by slowly adding the product solution to heptane (35 L). The resulting white suspension was stirred at 20° C. to 25° C. for 15 minutes, and then the product was isolated by filtration. The filter cake was washed with heptane (2×0.5 L) and dried under vacuum at 35° C. for 18 hours to give 252.4 g of the desired product as a white solid, Ac-Pen(Trt)-Asn-Thr(tBu)-OH.

[1567] (yield 83.0%, ESI-MS: m / z=1408.74 [2M+H + ] + ).

[1568] Example II-5: Fmoc-Trp(7Me)-Lys(Ac)-Pen(acm)-Tyr(2-Boc-ea)-OH (FG1 tetrapeptide) synthesis

[1569] Example II-5a: Synthesis of Fmoc-Pen(Acm)-Tyr(2-Boc-ea)-OMe

[1570]

[1571] Fmoc-Pen(Acm)-OH (0.79 mol, 1.0 equivalent), H-Tyr(2-Boc-ea)-OMe (0.81 mol, 1.02 equivalent) and Oxyma Pure (0.79 mol, 1.0 equivalent) were dissolved in EtOAc (3.5 L). DIC (0.87 mol, 1.1 equivalent) was added at 23 ° C over 2 hours. IPC-HPLC after 1 hour showed that the reaction was complete. The reaction mixture was filtered and the filter cake was washed with EtOAc. The product solution was washed with a NaHSO4 aqueous solution, a NaHCO3 aqueous solution and water. The solvent was evaporated under reduced pressure at 35 ° C, and the resulting residue was co-evaporated three times with EtOAc. The residue was absorbed in Me-THF (2 L), and the product solution was precipitated by adding the solution to pentane (35 L) within 30 minutes. The white suspension was separated by filtration, and the product was washed with pentane. The off-white product was dried in a vacuum oven at reduced pressure and 35 ° C over the weekend. 637.8 g of off-white solid Fmoc-Pen(Acm)-Tyr(2-Boc-ea)-OMe was obtained (HPLC purity: 93.8% product, yield 106%, ESI-MS: m / z=763.23 [M+H] + ).

[1572] Example II-5b: Synthesis of H-Pen(Acm)-Tyr(2-Boc-ea)-OMe

[1573]

[1574] Fmoc-Pen(Acm)-Tyr(2-Boc-ea)-OMe (0.786 mol, 1.0 eq) was dissolved in EtOAc / DMSO (9:1; v:v) (6 L). DBU (0.393 mol, 0.5 eq) was added to the solution. The reaction mixture was stirred at room temperature for 2.5 hours. IPC-HPLC after 2 hours showed 0.65% Fmoc-Pen(Acm)-Tyr(2-Boc-ea)-OMe. The organic product layer was diluted with EtOAc and washed with 5% NaHCO3 aqueous solution and H2O. The aqueous phase was washed with EtOAc. The organic phases were combined and evaporated at 35°C. The residue was co-distilled twice with EtOAc. The residue was stored at 4°C to 5°C overnight and used directly as the starting material for coupling with Fmoc-Lys(Ac)-OH.

[1575] H-Pen(Acm)-Tyr(2-Boc-ea)-OMe was diluted in EtOAc / DMSO (8:2; v:v) (3 L). 100 μl (93.0 mg) of the solution was diluted in 10 ml of ACN and analyzed by HPLC. The mass of the solution: 4409.5 g. The amount of H-Pen(Acm)-Tyr(2-Boc-ea)-OMe was calculated using a non-qualified standard for this compound. The amount of H-Pen(Acm)-Tyr(2-Boc-ea)-OMe was calculated to be 396.91 g (yield: 93.3%, HPLC purity 96.98).

[1576] Example II-5c: Synthesis of Fmoc-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-Ome

[1577]

[1578] To a mixture of H-Pen(Acm)-Tyr(2-Boc-ea)-OMe (0.732 mol, 1.0 equiv) in EtOAc / DMSO (8:2; v:v) (3 L) was added Fmoc-Lys(Ac)-OH (0.637 mol, 0.87 equiv) and TBTU (0.696 mol, 0.95 equiv), and the reaction mixture was stirred at room temperature for 2 minutes. DIPEA (1.391 mol, 1.90 equiv) was added and the reaction mixture was stirred at room temperature. IPC-HPLC after 1 hour showed 2.1% H-Pen(Acm)-Tyr(2-Boc-ea)-OMe and no Fmoc-Lys(Ac)-OH was detected. Fmoc-Lys(Ac)-OH (18.6 mmol, 0.025 equiv) was added. IPC-HPLC after 2 hours showed 0.81% H-Pen(Acm)-Tyr(2-Boc-ea)-OMe. The reaction mixture was diluted with EtOAc and washed twice with a 20% NaHSO4 aqueous solution, H2O, twice with a 5% Na2CO3 aqueous solution, and again with water. Because the HPLC of the organic phase still showed 0.68% H-Pen(Acm)-Tyr(2-Boc-ea)-OMe, the organic phase was again washed twice with a 20% NaHSO4 aqueous solution, H2O, twice with a 5% Na2CO3 aqueous solution, and again with water. The HPLC of the organic phase showed 0.60% H-Pen(Acm)-Tyr(2-Boc-ea)-OMe. The aqueous phase was washed with EtOAc. The organic phase was stored at 4°C to 5°C overnight. The organic phase was evaporated at 35°C and co-distilled twice with EtOAc. The residue was dissolved in EtOAc. The mixture was slowly added to IPE over 25 minutes. The suspension was filtered and washed three times with IPE. The solid was dried at 35°C under high vacuum overnight. The white solid was dissolved in EtOAC. The solution was added to IPE over 5 minutes. The suspension was filtered and washed three times with IPE. The solid was dried at 35°C under high vacuum overnight. 554.9 g of white solid Fmoc-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe was obtained (HPLC-purity 97.05% product, ESI-MS: 933.32 m / z [M+H] + , two-step yield 75.6%).

[1579] Example II-5d: Synthesis of H-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe

[1580]

[1581] Fmoc-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe (0.563 mol, 1.0 eq) was dissolved in EtOAc / DMSO (9:1; v:v) (5.2 L). DBU (0.281 mol, 0.5 eq) was added to the solution. The reaction mixture was stirred at room temperature for 1.5 hours. IPC-HPLC after 1 hour showed 0.03% Fmoc-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe. The organic product layer was diluted with EtOAc and washed twice with H2O.

[1582] The aqueous phase was washed twice with EtOAc. The organic phases were combined and evaporated at 40°C. The residue was co-distilled twice with EtOAc. The residue was stored at 4°C to 5°C overnight and used directly as the starting material for coupling with Fmoc-7-Me-Trp-OH.

[1583] H-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe was diluted in EtOAc / DMSO (8:2; v:v) (2.6 L). 100 μl (89.3 mg) of the solution was diluted in 10 ml of MeOH and analyzed by HPLC. The mass of the solution: 3517 g. The amount of H-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe was calculated using an unqualified standard for this compound. The amount of H-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe was calculated to be 367 g (91.7% yield, 97.8% HPLC purity).

[1584] Example II-5e: Synthesis of Fmoc-Trp(7Me)-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe

[1585]

[1586] To a mixture of H-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe (0.512 mol, 1.0 equiv) in EtOAc / DMSO (8:2; v:v) (2.6 L) was added Fmoc-Trp(7Me)-OH (0.415 mol, 0.81 equiv) and TBTU (0.486 mol, 0.95 equiv), and the reaction mixture was stirred at room temperature for 2 minutes. DIPEA (1.024 mol, 2.00 equiv) was added and the reaction mixture was stirred at room temperature. IPC-HPLC after 1 hour showed 0.41% H-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe, and no Fmoc-Trp(7Me)-OH was detected. After 2 hours, the reaction mixture was diluted with EtOAc and washed twice with 5% aqueous NaHCO3. The aqueous phase was washed with EtOAc. The organic phase was evaporated at 40°C. The residue was azeotroped twice with EtOAc. The residue was stored at 4°C to 5°C overnight. The residue was diluted with EtOAc and slowly added to IPE / heptane (1:1; v:v) over 10 minutes. The suspension was filtered and washed three times with IPE. The solid was dried at 35°C under high vacuum overnight. 487.67 g of white solid Fmoc-Trp(7Me)-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe was obtained (HPLC-purity 95.04%, ESI-MS 1133.33 m / z [M+H] + , two-step yield 76.48%).

[1587] Example II-5f: Synthesis of H-Trp(7Me)-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe

[1588]

[1589] To a solution of Fmoc-7Me-Trp-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe (450 g, 397 mmol, 1.0 eq) in EtOAc / DMSO (8:2, v:v) (4.5 L) was added DBU (29.63 mL, 198.5 mmol, 0.5 eq) at room temperature, and the reaction mixture was stirred at room temperature. IPC-HPLC after 1 hour showed 0.01% Fmoc-7-Me-Trp-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe. After 1.5 hours, the reaction mixture was diluted with EtOAc / Me-THF 1:1 (9.0 L). The organic solution was washed twice with NaHCO (5% in water) (4.5 L) and H O (4.5 L). The aqueous phase was washed with EtOAc / Me-THF 1:1 (4.5 L). The organic phase was evaporated under reduced pressure at 40°C (AT). The residue was co-evaporated with EtOAc (3 x 2 L). The residue was stored at 4°C to 5°C overnight.

[1590] The residue was taken up in EtOAc (1 L) to give a total volume of 3 L. The diluted mixture was added dropwise to IPE (30 L) over 5 minutes. The suspension was stirred at room temperature for 10 minutes. The suspension was filtered and washed twice with IPE (1.5 L). The white solid was dried at 35 ° C under high vacuum overnight. The white solid was dissolved in EtOAc (3.5 L) for 10 minutes. The solution was added to IPE (35 L) over 10 minutes. The white suspension was stirred at room temperature for 30 minutes. The white suspension was filtered and washed twice with IPE (1.5 L). The white solid H-Trp(7Me)-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe was dried under high vacuum at 35 ° C overnight. (HPLC-purity: 95.59% ESI-MS: 911.56m / z[M+H] + , yield 92.9%)

[1591] Example II-6: Ac-Pen(Trt)-Asn-Thr(tBu)-Trp(7Me)-Lys(Ac)-Pen(acm)-Tyr(2- Synthesis of Boc-ea)-OMe(Ac-FG1-OMe)

[1592]

[1593] A double-jacketed 10 L glass reactor was charged with Ac-Pen(Trt)-Asn-Thr(tBu)-OH (212.0 g, 273.692 mmol, 1.0 equiv), H-7Me-Trp-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe (275.4 g, 281.903 mmol, 1.03 equiv), Oxyma (50.7g, 273.692mmol, 1.0 equivalent) and acetonitrile (3.23kg, 4.2L). The mixture was stirred at 25°C for 30 minutes (red-fine suspension), DIC (38.0g, 301.061mmol, 1.1 equivalent) was added over 5 minutes, and the reaction mixture was stirred at 25°C. IPC-HPLC after 3 hours showed that the reaction was complete. A white to beige suspension was formed. The suspension was stirred at 25°C for another 21 hours, filtered through a 3-pore glass filter to separate the product, and the filter cake was washed with AcN (3×0.3L). The wet product was resuspended in AcN (2.0L, 1.55kg), and the suspension was heated to 40°C over 30 minutes and stirred at this temperature for 1.5 hours. The suspension was cooled to 15°C over 1 hour and stirred at this temperature for 6 hours.

[1594] The product was isolated by filtration through a 3-pore glass filter. The filter cake was washed with AcN (3×0.3 L mL) and dried under reduced pressure at 35° C. to give 364.0 g of an off-white to beige solid Ac-Pen(Trt)-Asn-Thr(tBu)-Trp(7Me)-Lys(Ac)-Pen(acm)-Tyr(2-Boc-ea)-OMe (yield: 83.2%, HPLC purity: 97.0%, ESI-MS: m / z=1597.32 [M+H + ] + ).

[1595] Example II-7: Ac-Pen(Trt)-Asn-Thr(tBu)-Trp(7Me)-Lys(Ac)-Pen(acm)-Tyr(2- Synthesis of Boc-ea)-OH(Ac-FG1-OH(straight chain))

[1596]

[1597] Ac-FG1-OMe (150.0 g, 89.1% w / w, 83.637 mmol, 1.0 equivalent), THF (0.75 L, 0.657 Kg) and water (0.525 L, 0.525 kg) were charged into a 1.5 L glass jacketed reactor with an overhead stirrer. The mixture was stirred at 25 ° C until a solution was obtained and cooled to 0 ° C within 30 minutes. A solution of LiOH x H2O (5.264 g, 125.455 mmol, 1.5 equivalents) in water (0.225 L, 0.225 kg) was added to the reaction mixture under stirring within 1 hour, and the temperature was maintained at 0 ° C to 2 ° C. After completing the addition of the LiOH solution for 2 hours, IPC-HPLC showed that the reaction was complete. The pH of the reaction mixture was adjusted to 4.9 with HCl (concentrated) and heated to 25 ° C within 30 minutes. The reaction mixture was diluted with MeTHF (1.5 L) and the phases were separated. The solvent was evaporated under reduced pressure at 40°C to about 300 mL, and the residue was co-evaporated with EtOAc (3×1 L). After the second co-evaporation, the product began to crystallize. The residue was absorbed in EtOAc (820 mL), stirred at 60°C for 30 minutes, cooled to 25°C within 4 hours, and stirred at this temperature overnight. The product was isolated by filtration through a 3-pore glass filter, and the filter cake was washed with EtOAc (200 mL). The product was vacuum dried at 35°C for 24 hours to give 135.7 g of beige to white solid Ac-Pen(Trt)-Asn-Thr(tBu)-Trp(7Me)-Lys(Ac)-Pen(acm)-Tyr(2-Boc-ea)-OH. (Yield: 82.8%, HPLC purity: 96.1% ESI-MS: m / z=1583.36 [M+H + ] + )

[1598] Example II-8: Ac-Pen(Trt)-Asn-Thr(tBu)-Trp(7Me)-Lys(Ac)-Pen(acm)-Tyr(2- Synthesis of Boc-ea)-OH(SS, 1-6)(Ac-FG1-OH(cyclic))

[1599]

[1600] In a 20 L glass reactor, a solution of iodine (123.2 g, 3.40 eq, 485.5 mmol) and potassium iodide (80.6 g, 3.40 eq, 485.5 mmol) in acetone / water (8:2; 12.0 L) was stirred at 25° C. for 30 minutes. A solution of Ac-FG1-OH (linear) (273.7 g, HPLC assay: 82.65%, 1 eq, 142.8 mmol) in acetone / water (8:2; 2.28 L) (slightly turbid to thin suspension) was added over 8 hours at 25° C. under a nitrogen atmosphere using a metering pump (concentration: 10 mM). The reaction mixture was stirred at 25°C overnight (15 hours), cooled to 15°C, and a solution of sodium thiosulfate pentahydrate (241.0 g, 6.80 equivalents, 971.0 mmol) in water (714 mL) was added over 15 minutes to give a clear, pale yellow solution. NaHCO3-5% (500 mL) was added to adjust the pH from 2.8 to 5.0. The reaction mixture became slightly turbid and took on a rose color. The reaction mixture was transferred to a 20 L rotary evaporator, and all equipment was rinsed with acetone (250 mL) and the rinse was transferred together. The mixture was evaporated under reduced pressure at 40°C to remove the acetone. The residue (a clear, rose-colored solution with an oily product adhering to the vessel wall) was diluted with brine (1.3 L) and Me-THF (2.3 L). The pH was adjusted from 6.2 to 3.0 with NaHSO4-5%. The mixture was stirred for 20 minutes until all dissolved. The phases were separated, and the aqueous phase (pH 3.8) was extracted with Me-THF (1 x 1.5 L) and NaHSO4-5% (20 mL). pH (UP2): 3.6. The combined organic phases were washed with brine 10% (3 x 0.80 L). The final separation required 30 minutes for complete separation.

[1601] The organic phase (3.85 L) was evaporated under reduced pressure at 40° C. to a turbid solution (2.50 L). The dilute suspension was azeotropically distilled with Me-THF (4×500 mL) to form a white, viscous but stirrable suspension during the third portion (residue: 2.50 L / 2.32 kg). The suspension was diluted with MTBE (2000 mL) and heptane (500 mL) and stirred at 25° C. for 15 minutes. Filtered and washed with MTBE (4×250 mL). The product was dried in a vacuum oven at 40° C. for 18 hours.

[1602] The product (215.6 g) was dissolved in EtOAc (6.00 L) and water (210 mL) on a rotary evaporator at 65° C. The slightly cloudy rose-colored solution was clarified and filtered on a Por3 glass filter and washed with EtOAc (500 mL, 50° C.). The entire solution was transferred to a 20 L glass reactor at AT=55° C. The rose-colored solution had already begun to become cloudy (55° C.) and seeding was also performed at this time. Stir at 45° C. for 15 minutes. Then stir at 35° C. for 1 hour. Then stir at 25° C. for 2 hours and at 20° C. for 18 hours. Then cool and stir at 0° C. for 2 hours. The white suspension was filtered and washed with EtOAc (3×350 mL). The product Ac-Pen(Trt)-Asn-Thr(tBu)-Trp(7Me)-Lys(Ac)-Pen(acm)-Tyr(2-Boc-ea)-OH(SS, 1-6)(Ac-FG1-OH(cyclic)) was dried in a vacuum oven at 40°C. (ESI-MS: [M+H]+: 1268.55)

[1603] Example II-9: Ac-Pen(Trt)-Asn-Thr(tBu)-Trp(7Me)-Lys(Ac)-Pen(acm)-Tyr(2- Synthesis of Boc-ea)-2Nal-αMe-Lys(Boc)-Lys(Ac)-Asn-D-Leu-NH2(SS, 1-6)

[1604]

[1605] In a 400 mL flask, Ac-FG1[SS]-OH (15.00 g, 1 eq, 10.61 mmol, HPLC: 97.4%, assay: 89.7%), H-FG2+3-NH2 (10.12 g, 1.03 eq, 10.92 mmol, HPLC: 97.6%, assay: 92.2%), and Oxyma-B (2.160 g, 1.10 eq, 11.67 mmol) were dissolved in DMF (60 mL, synthesis quality). The dark purple solution was diluted with Me-THF (240 mL). The purple solution was stirred at 25°C. DIC (1.339 g, 1.66 mL, 1.00 eq, 10.61 mmol) was added in one portion and stirred at 25°C for 6 hours. (No exothermic reaction was observed with the addition of DIC). DIC (334.6 mg, 415 μL, 0.25 eq., 2.652 mmol) was added and further stirred at 25°C.

[1606] After 24 hours, the reaction mixture was diluted with Me-THF (240 mL). The red solution was washed with NaHSO4-5% solution (1 x 200 mL and 2 x 60 mL), NaHCO3-5% solution (1 x 200 mL and 2 x 60 mL), NaCl-10% (2 x 60 mL), and water (1 x 60 mL). HPLC-4: 93.3% product.

[1607] The organic phase was evaporated under reduced pressure at 45°C to give an orange solution (92 g). The solution was co-distilled with MeTHF / MeOH (9:1; 2 x 100 mL). 90 g of solution was obtained (a test precipitate indicated that the solution would be concentrated). The mixture was diluted to 140 g with Me-THF. The product was an oil. MeOH (5 mL) was added to form an orange solution. The solution was added to EtOAc (800 mL) at room temperature over 20 minutes. A fine white suspension was formed. Stir for 1 hour.

[1608] Several additional batches of Ac-Pen(Trt)-Asn-Thr(tBu)-Trp(7Me)-Lys(Ac)-Pen(acm)-Tyr(2-Boc-ea)-2Nal-αMe-Lys(Boc)-Lys(Ac)-Asn-D-Leu-NH2(SS, 1-6) were added to the material prepared above (1.56 g, 0.499 g, and 1.353 g), and the mixture was stirred for 15 minutes. The suspension was filtered and washed with EtOAc (3×). The product was dried in a vacuum oven at 40°C for 18 hours to give Ac-Pen(Trt)-Asn-Thr(tBu)-Trp(7Me)-Lys(Ac)-Pen(acm)-Tyr(2-Boc-ea)-2Nal-αMe-Lys(Boc)-Lys(Ac)-Asn-D-Leu-NH2(SS, 1-6), 26.17 g / 100%.

[1609] Example II-10: Ac-Pen-Asn-Thr-Trp(7Me)-Lys(Ac)-Pen-Tyr(2-ea)-2Nal-αMe- Synthesis of Lys-Lys(Ac)-Asn-D-Leu-NH2(SS, 1-6)

[1610]

[1611] Ac-Pen(Trt)-Asn-Thr(tBu)-Trp(7Me)-Lys(Ac)-Pen(acm)-Tyr(2-Boc-ea)-2Nal-αMe-Lys(Boc)-Lys(Ac)-Asn-D-Leu-NH2(SS, 1-6) (12.6 g, 5.987 mmol, 1.0 eq), HFIP (100 mL) and DODT (5 mL) were charged into a 250 mL Systag reactor and the mixture was stirred at 25°C until a solution was formed. A solution of 4N HCl in EtOAc (25 mL) pre-cooled at 4°C was added to the reaction mixture over 5 minutes and the reaction mixture was stirred at 25°C to 30°C (the temperature was observed to initially rise to 33°C). 45 minutes after the addition was complete, IPC-HPLC showed the reaction was complete. One hour after the addition of 4N HCl was completed, the product was precipitated by slowly adding EtOAc (130 mL) pre-cooled at 5°C to the reaction mixture. The formed white suspension was cooled to 4°C within 10 minutes and stirred at this temperature for 15 minutes. The product was isolated by filtration through a 3-pore glass filter and the filter cake was washed with EtOAc (2×20 mL). The product was dried in vacuo at 35°C for 18 hours to give 12.94 g of white solid Ac-Pen-Asn-Thr-Trp(7Me)-Lys(Ac)-Pen-Tyr(2-ea)-2Nal-αMe-Lys-Lys(Ac)-Asn-D-Leu-NH2(SS, 1-6) (HPLC purity: 92.3%, ESI-MS: m / z=924.88 Da [M+2H + ] 2+ , assay: 75.6%, yield: 112.5%, not corrected for assay).

[1612] Example II-10a: Ac-Pen-Asn-Thr-Trp(7Me)-Lys(Ac)-Pen-Tyr(2-ea)-2Nal-αMe- Preparation of HCl salt of Lys-Lys(Ac)-Asn-D-Leu-NH2(SS, 1-6)

[1613] 5.0 g of the crude product was dissolved in 1-PrOH: water (80:20, v:v) (25 mL) at 40° C., and the turbid solution was filtered through a 3-pore glass filter. The solution was cooled to 15° C. within 45 minutes, seeded with 50 mg (1%) of seed crystals, and stirred at this temperature for 1 hour.

[1614] 1-PrOH (75 mL, 62 g) was added to the reaction mixture over 3 hours (white precipitate formed).The temperature was adjusted to 0°C over 4 hours and stirred at this temperature overnight.

[1615] The product was isolated by filtration through a 3-pore glass filter (slow filtration), and the filter cake was washed with 1-PrOH (5 mL) at 0°C. The product was dried under vacuum at 35°C over the weekend to give 3.2 g of a white powder, Ac-Pen-Asn-Thr-Trp(7Me)-Lys(Ac)-Pen-Tyr(2-ea)-2Nal-αMe-Lys-Lys(Ac)-Asn-D-Leu-NH2(SS, 1-6)xHCl. (HPLC purity: 95.8%, ESI-MS: m / z=924.91 Da [M+2H + ] 2+ , HPLC determination: 93.1%, yield: 78.8%).

[1616] Example II-10b: Ac-Pen-Asn-Thr-Trp(7Me)-Lys(Ac)-Pen-Tyr(2-ea)-2Nal-αMe- Preparation of Lys-Lys(Ac)-Asn-D-Leu-NH2(SS, 1-6) acetate

[1617] A solution of Ac-Pen-Asn-Thr-Trp(7Me)-Lys(Ac)-Pen-Tyr(2-ea)-2Nal-αMe-Lys-Lys(Ac)-Asn-D-Leu-NH2(SS, 1-6)x HCl salt (5.0 g) in 100 mL of MeOH:HO (9:1, v:v) (turbid solution) was filtered through a Lewatit MP64 (acetate form) (25 g) column and the column was washed with water (300 mL). The eluate was collected in 50 mL fractions and analyzed by TLC to detect the presence of the product. The fractions of interest (approximately 250 mL) were mixed and the solution was filtered through a 0.45 μm TPP filter. The filtered solution was frozen and freeze-dried to give 5.02 g of white powder Ac-Pen-Asn-Thr-Trp(7Me)-Lys(Ac)-Pen-Tyr(2-ea)-2Nal-αMe-Lys-Lys(Ac)-Asn-D-Leu-NH2(SS, 1-6)x acetate (HPLC purity: 96.9%, ESI-MS: m / z=924.88 Da [M+2H + ] 2+ , HPLC determination: 92.9%, yield: 98.0%).

[1618] The following reaction schemes may aid in understanding the reactions discussed throughout the following examples.

[1619] Reaction Scheme III

[1620]

[1621] Example III-1: Synthesis of Fragment 2 Example III-1a: Synthesis of H-THPGly-OMe*HCl

[1622]

[1623] In a 500mL flask, MeOH (300ml) was cooled to -5°C. At -5°C to 0°C, thionyl chloride (31.7g / 2.0 equivalents) was added over 20 minutes and stirred for 15 minutes. At -2°C to 0°C, H-THPGly-OH (20.00g / 1.00 equivalents) was added portionwise to the reaction mixture over 2 minutes and stirred at 0°C for 15 minutes. It was then heated to reflux at 75°C (jacket temperature) and stirred under reflux. The solution was evaporated to an oily substance. IPE (250mL) was added to form a white suspension. After stirring at room temperature for 15 minutes, the suspension was filtered and washed with 4×20ml IPE. The product was dried under reduced pressure at 40°C in a vacuum oven to give 24.49g (91%) of product.

[1624] Example III-1b: Synthesis of Boc-2-Nal-THPGly-OMe

[1625]

[1626] In a 2L flask, Boc-2-Nal-OH (70.00g / 1.0 equivalent) and H-THPGly-OMe*HCl (46.60g / 1.05 equivalent) were dissolved in DMF (700mL). The clear yellow solution was cooled to 10°C and NMM (76ml / 3.1 equivalent) was added. The formed white dilute suspension was cooled to 0°C. TBTU (78.40g / 1.1 equivalent) was added once. The suspension was stirred in an ice bath for 2 hours. The temperature was then raised to 20°C and further stirred within 30 minutes. The reaction mixture was stirred at room temperature (25°C) overnight. The reaction mixture was diluted with EtOAc (1400mL) and washed with NaHCO solution (2%, 800ml). The aqueous layer was extracted with EtOAc (300ml). The combined organic layers were washed with NaHCO solution (2%) / NaCl solution (5% aqueous solution) (800 ml) and NaCl solution 10% (2 x 400 ml). The organic layer was dried over Na SO and filtered to clarify. The filtrate was evaporated under reduced pressure at 45°C to an oily substance and co-distilled with EtOAc (100 ml) to form 180 g of residue. The EtOAc oil was diluted with IPE (245 ml) and made turbid with heptane (180 ml). The turbid solution was seeded and formed into a white, very thick suspension after 10 minutes. The suspension was diluted with heptane (820 ml) and stirred for another 30 minutes. The product was filtered, washed with heptane (4 x 80 ml) and dried in a vacuum oven at 40°C to obtain 86.61 g / 85% product.

[1627] Example III-1c: Synthesis of Boc-2-Nal-THPGly-OH

[1628]

[1629] Boc-2-Nal-THPGly-OMe (86.50 g / 1.0 equivalent) was stirred in dioxane (680 ml) and water (1020 ml) in a flask. NaOH 30% (29.1 mL / 1.5 equivalent) was added and stirred at room temperature (pH 14.0). After 15 minutes, a cloudy solution with some lumps was formed. Dioxane (120 mL) and water (180 mL) were added. After 4 hours, the almost clear solution turned into a colloidal suspension. Water (200 ml) was added and the suspension became thinner; the temperature rose from 26° C. to 40° C. At 35° C., the reaction mixture was a clear light yellow solution. After 5 hours, the solution was evaporated under reduced pressure at 50° C. (dioxane was removed, 850 ml of distillate). The aqueous solution formed a thick gel. The gel was diluted with water (700 ml) and cooled to 20° C. The pH was adjusted to 3 with NaHSO4 solution (5%, 300 mL) and NaHSO4 solution (20%, 50 mL). A gel began to form as a fine white suspension. The suspension was stirred for 15 minutes. The thin white suspension was filtered and washed with water (3 x 150 mL). The product was dried in a vacuum oven at 45°C to yield 83.05 g / 99% product.

[1630] Example III-1d: Synthesis of H-2-Nal-THPGly-OH*HCl

[1631]

[1632] In a flask, HCl / dioxane solution (4M, 415 mL) was cooled to 0°C. Boc-2-Nal-THPGly-OH (83.0 g) was added as a solid at a maximum of 12°C over 10 minutes and rinsed with dioxane (15 mL). The suspension was stirred in an ice bath. After 45 minutes, the reaction mixture was precipitated in IPE (2.1 L). The dilute white suspension was filtered and washed with IPE (4 x 150 mL). The product was dried in a vacuum oven at 40°C to give 72.97 g of product.

[1633] Example III-1e: Synthesis of Fmoc-Tyr(2-Boc-ea)-OSu

[1634]

[1635] In a 250 mL flask, Fmoc-Tyr(2-Boc-ea)-OH (10.00 g / 1.00 equiv) and HOSu (2.32 g / 1.1 equiv) were dissolved in THF (100 mL dried over molecular sieves) at 20°C under a N2 atmosphere. The clear, colorless solution was cooled to 0°C. A solution of DCC (4.17 g / 1.1 equiv) in THF (50 mL dried over molecular sieves) was added over 120 minutes at 0±2°C (dosage rate 0.5 g / minute). The dosage unit was rinsed with THF (10 mL; dried over molecular sieves) and the rinse was transferred to the reactor. The white suspension was stirred at 0±2°C for 30 minutes. The temperature was then increased to 15°C over 600 minutes (constant temperature ramp). The suspension was clarified by filtration, and the white residue was washed with THF (2×20 mL). The clear colorless filtrate was evaporated under reduced pressure at 40°C to a thick oil (20 g). The oil was diluted with IPA (150 mL) and stirred at 40°C for 5 minutes until a light yellow solution appeared. It was then stirred at room temperature. After stirring for 10 minutes, a white thick suspension was formed. The suspension was cooled to 5°C to 10°C, stirred for 30 minutes, filtered, and washed with IPA (4 × 5 mL). The product was dried in a vacuum oven at 35°C to obtain 10.99 g / 93% product.

[1636] Example III-1f: Synthesis of Fmoc-Tyr(2-Boc-ea)-2-Nal-THPGly-OH (Fragment 2)

[1637]

[1638] In a 400 mL flask, Fmoc-Tyr(2-Boc-ea)-OSu (20.00 g / 1.00 equiv) and H-2-Nal-THPGly-OH*HCl (12.3 g / 1.05 equiv) were dissolved in THF (dried over molecular sieves, 250 ml) at 20 ° C. The slightly cloudy solution was cooled to 15 ° C. At 15 ° C, a solution of DIPEA (10.04 g / 2.50 equiv) in THF (dried over molecular sieves, 50 ml) was added over 3 hours. The reaction mixture was heated to 20 ° C for 4 hours; DIPEA (1.35 mL / 0.25 equiv) was added. The reaction mixture was heated to 30 ° C within 20 minutes. The reaction mixture was stored in a refrigerator (5 ° C) over the weekend. The reaction mixture was evaporated under reduced pressure at 40 ° C to give an oil. The oil was dissolved in EtOAc (300 mL), washed with NaHSO4 (5%, 2×100 mL) and washed with NaCl solution (10%, 2×50 mL). The organic phase was evaporated under reduced pressure at 40°C to give 140 g of residue. The solution was diluted with IPE (60 mL) until cloudy. The cloudy solution was stirred until a thick suspension was formed. The suspension was diluted with IPE (200 mL) and stirred for 1 hour. The white suspension was filtered and washed with IPE (3×50 mL). The product was dried in a vacuum oven at 40°C to give 25.87 g / 96% product. At 25°C, the product was dissolved in EtOAc (200 mL). The solution was converted into a very fine suspension with IPE (120 mL) and further stirred at room temperature until it crystallized. The suspension was diluted with IPE (200 mL), filtered, and washed with IPE (3×60 mL). The product was dried in a vacuum oven at 40°C to yield 23.60 g / 87% product.

[1639] Example III-2: Synthesis of Fragment 3

[1640]

[1641] Example III-2a: Synthesis of H-Asn-NH2*HCl

[1642]

[1643] Boc-Asn-ONp (100.0 g, 1.0 equiv) was suspended in Me-THF (2.0 L) and NH3 / MeOH solution (100.0 mL) was added. The reaction mixture immediately turned yellow and formed a suspension. After 15 minutes, IPE (2.5 L) was added to the yellow suspension. The suspension was filtered and washed with IPE (10 x 250 mL). The white product was dried in a vacuum oven at 40°C under reduced pressure overnight. Boc-Asn-NH2: 50 g (65%).

[1644] Boc-Asn-NH2 (4.5 g) was suspended in DMF (35 mL). A solution of HCl in dioxane (approximately 4 M, 75 mL) was then added. The mixture dissolved within 2 minutes, and a white suspension formed after 40 seconds. The suspension was stirred for 15 minutes, then filtered and washed with DMF (3 x 20 mL). The product was dried at 40°C / HV. H-Asn-NH2*HCl: 3.0 g (92%).

[1645] Boc-Asn-NH2 (50.0 g, 1.0 eq.) was suspended in DMF (500 mL). A solution of HCl in dioxane (approximately 4 M, 400 mL) was then added. The temperature was raised to 50°C. The mixture dissolved within 2 minutes. After 10 minutes, when the temperature was cooled to 44°C, the product began to crystallize. Stir for 2 hours until the temperature reached 20°C to 25°C, then filter and wash with DMF (3 x 200 mL). The product was dried at 40°C / HV. H-Asn-NH2*HCl: 17.5 g (48.3%).

[1646] Example III-2b: Synthesis of Z-Asn(Trt)-Asn-NH2

[1647]

[1648] Z-Asn(Trt)-OH (10.93 g, 0.90 eq) was dissolved in DMF (95 mL). TBTU (1.0 eq) was then added and stirred again until a colorless solution was obtained. In another flask, H-Asn(Trt)-NH2*HCl (4.12 g, 1.0 eq, assay: 102.94%) was added and dissolved in DMSO (25 mL). This turbid solution was added to the first mixture. NMM (15 mL, 5.65 eq) was then added, and the reaction mixture was stirred at room temperature (pH reached pH 7.5 to 8.0). After 1 hour, the mixture was evaporated at 60°C / HV. The thick oil (+DMSO) was dissolved in EtOAc (25 mL) and precipitated into water (800 mL, 1 / 16 v:v). The product was filtered, washed with water (2 x 20 mL) and EtOAc (2 x 20 mL), and dried at 40 °C / HV to give Z-Asn(Trt)-Asn-NH2: 11.6 g - 78.2%.

[1649] Example III-2c: Synthesis of H-Asn(Trt)-Asn-NH2*HCl

[1650]

[1651] In a hydrogenator, Z-Asn(Trt)-Asn-NH2 (0.200 g, 1.0 equivalent) was suspended in MeOH / H2O (95:5) (10 mL) and Pd / C 5% (0.023 g) was added. Hydrogenation was started at 45°C / 3.5 bar H2 pressure. After 30 minutes, a solution (with black catalyst particles) was formed. The reaction mixture was clarified by filtration and washed with MeOH. The filtrate was evaporated under reduced pressure at 45°C to give a white oily solid. The solid was co-distilled with EtOAc (2×10 ml) and dissolved in MeOH (2 mL). The solution was precipitated in IPE (15 mL). The suspension was centrifuged and the product was washed once with IPE (20 mL). The product was dried in a vacuum oven at 40°C to give a white powder.

[1652] Example III-2d: Synthesis of Z-Glu(OtBu)-OH

[1653]

[1654] After adding MTBE (1.5 L) and water (0.25 L) to the flask, Z-Glu (OtBu) -OH * DCHA (400.0 g) was weighed into a 3 L flask. H2SO4 solution (50%, 100 mL) was added to the white suspension until the pH reached 1.5. When the pH reached pH 2.0, the suspension began to dissolve. The layers were separated and the aqueous layer was washed with MTBE (400 mL). The organic layer was evaporated to an oil at 60 ° C / HV and dried by azeotropic distillation with EtOAc (3 × 300 mL). IPE (1 L) and seed crystals were added to the oil and stirred at room temperature overnight. The white suspension was filtered, washed with IPE (2 × 200 mL) and dried at 40 ° C / HV. Z-Glu (OtBu) -OH 99.5 g / 37%.

[1655] Example III-2e: Synthesis of Z-Glu(OtBu)-Asn(Trt)-Asn-NH2

[1656]

[1657] In a flask, Z-Glu(OtBu)-OH (5.73 g, 1.00 equiv) and H-Asn(Trt)-Asn-NH2 (8.28 g, 1.00 equiv) were dissolved in DMF (85 mL). The solution was cooled to 0°C. In an ice bath (AT = 0°C), DIPEA (9.2 mL, 3.10 equiv) was added, followed by TBTU (6.00 g, 1.1 equiv). The AT was raised to 10°C → a clear, light yellow solution formed. The solution was stirred at 0°C for 1 hour and then at room temperature (25°C) for 1 hour. The reaction mixture was precipitated by the addition of NaHCO3 (2%) solution (400 ml). The white suspension was filtered and washed with water (4 x 100 mL) and EtOAc (3 x 80 mL). The product was dried in a vacuum oven at 45°C to give 12.08 g / 88% product.

[1658] Example III-2f: H-Glu(OtBu)-Asn(Trt)-Asn-NH Synthesis of 2 (fragment 3)

[1659]

[1660] In a hydrogenation flask, Z-Glu(OtBu)-Asn(Trt)-Asn-NH2 (15.00 g) and Pd / C 5% (1.50 g) were suspended in methanol (135 mL) and water (15 mL). Hydrogenation was initiated at 45°C / 3.5 bar H2. After 1 hour, a black solution formed. The suspension was clarified by filtration and washed with methanol. Water (100 mL) was added to the filtrate. The filtrate (80 mL distillate) was evaporated under reduced pressure at 40°C. A thick suspension formed. Additional water (200 mL) was added. A viscous, stirrable suspension formed. The pH was raised to 8.5 with NaHCO3-5% solution (approximately 20 mL). The suspension was filtered and washed with water (3×80 mL) and EtOAc (3×40 mL). The product was dried in a vacuum oven at 45°C to yield 11.16 g / 89% product.

[1661] Example III-3: Synthesis of Fragment 2+3

[1662] Example III-3a: Fmoc-Tyr(2-Boc-ea)-2-Nal-THPGly-Glu(OtBu)-Asn(Trt)-Asn- NH2(Fmoc-FG2+3-NH2)

[1663]

[1664] In a 500 mL flask, H-Glu(OtBu)-Asn(Trt)-Asn-NH2 (13.96 g / 1.00 equiv) and Fmoc-Tyr(2-Boc-ea)-2-Nal-THPGly-OH (18.3 g / 1.00 equiv) were suspended in 2-Me-THF (324 mL) and DMSO (36 mL) (9 / 1). To this thick white suspension was added 2,4,6-trimethylpyridine (8.14 mL / 3.00 equiv). To the still thick suspension was added PyAOP (14.4 g / 1.05 equiv) in one portion. After stirring for 2 minutes, a yellow clear solution was formed. The reaction mixture was stirred at room temperature (25 ° C), 2,4,6-trimethylpyridine (2 mL) was added (pH raised to 7.5), and then stirred overnight. Another portion of PyAOP (0.7 g) was then added and the reaction mixture was further stirred at room temperature. The reaction mixture was washed with NaHCO3-5% solution (2×100mL) and brine (2×100mL). Na2SO4 was added to the organic layer, stirred for 5 minutes and filtered to clarify. The mother liquor was evaporated to an oily substance at 55°C / HV. The oily substance was dissolved in methanol (360mL). The clear solution was stirred at room temperature. Crystallization began after 3 minutes and a white suspension was formed (1 hour). The suspension was cooled to 18°C and stirred for another 30 minutes. The suspension was filtered and washed with methanol (4×50ml). The product was dried in a vacuum oven at 35°C to obtain 28.6g / 91.6% product.

[1665] Example III-3b: Synthesis of Fragment 2+3 (H-FG2+3-NH2)

[1666]

[1667] Fmoc-Tyr(2-Boc-ea)-2-Nal-THPGly-Glu(OtBu)-Asn(Trt)-Asn-NH2(Fmoc-FG2+3-NH2, 28.5g) was dissolved in 2-Me-THF (280mL) and DBU (4.18mL) was added. The reaction mixture was stirred at room temperature for 1.0 hour and precipitated in 2.8LIPE to form a white suspension. The suspension was filtered and washed twice with IPE (200mL). Drying overnight at 35°C / HV gave 25.1g-103.1% product (no determination correction was performed, the product contained dibenzofulvene). FG 2+3 (25.1g) was weighed in a 500mL round-bottom flask and MeOH (100mL) was added. To dissolve, it was warmed to 45°C and then stirred at room temperature. It began to crystallize. The suspension was stirred at room temperature for 1 hour, IPE (100 mL) was added, and then cooled to 0°C to 5°C and stirred at this temperature for 5 hours. The suspension was filtered and washed twice with IPE (100 mL). The product was then dried at 40°C / HV to yield 20.8 g (85.4%) of the product.

[1668] Example III-4: Synthesis of building blocks

[1669] Example III-4a: Synthesis of Boc-Hse-OAll

[1670]

[1671] Acetonitrile (3.0L) and Boc-Hse-OH (300.0g, 1.368mol, 1.0 equivalent) are loaded into a 10L glass reactor. The suspension formed is stirred at room temperature, and DIPEA (530.61g, 4.105mol, 3.0 equivalents) is added at a disposable rate. The reaction mixture is stirred at room temperature until a clear solution is obtained. To this solution, allyl bromide (331.13g, 2.736mol, 2.0 equivalents) is added, and the reaction mixture is stirred at room temperature. IPC-HPLC after 48 hours shows that the reaction has finished. Now, the solvent is evaporated under reduced pressure at 35°C until a white suspension begins to form. Residue is absorbed in EtOAc (3.0L), and the white suspension formed is stirred at room temperature for 10 minutes until a uniform white suspension is formed. The precipitate is separated by filtration, and the filter cake is washed with EtOAc (0.1L). The organic phase was then washed with 5% NaHCO (3 × 1.5 L), brine (1.5 L) and dried over anhydrous Na SO , and then evaporated under reduced pressure at 35 ° C to an oily substance. The oily substance was resuspended in IPE: heptane (1: 1, v: v) (3.0 L), and the suspension formed was stirred at room temperature for 0.5 hours until a clear white fine suspension was obtained. The solid was separated by filtration through a 3-pore glass filter, and the filter cake was washed with IPE: heptane (1: 1, v: v) (2 × 0.2 L). The solvent of the filtrate was evaporated under reduced pressure at 35 ° C to an oily substance, and dried under high vacuum at room temperature for 18 hours to obtain 260 g of a yellow oily substance, a yield of 73.3%.

[1672] Example III-4b: Synthesis of Boc-Abu(4-Cl)-OAll

[1673]

[1674] At 0 ℃ to 5 ℃, to the stirred solution of Boc-Hse-OAll (255.0g, 0.983mol, 1.0 equivalents) in DCM (2.0L), triethylamine (129.37g, 1.278mol, 1.3 equivalents) is added, and the reaction mixture is stirred at 0 ℃ to 5 ℃ for 5 minutes to 10 minutes. In 10 minutes, methylsulfonyl chloride (135.2g, 1.180mol, 1.2 equivalents) is added dropwise. After completing the addition of methylsulfonyl chloride, the reaction mixture is stirred at 0 ℃ to 5 ℃ for 10 minutes, and is heated to 20 ℃ to 25 ℃ in 30 minutes. After completing the addition of MsCl 2 hours, IPC-HPLC shows that the reaction is complete. The reaction mixture is filtered through 3 pore glass filters to remove the solid formed, and the solvent is evaporated under reduced pressure at 35 ℃ to an oily substance. The oil was redissolved in DMF (2.0 L), LiCl (208.5 g, 4.917 mol, 5 eq) was added and the reaction mixture was stirred at 20-25° C. IPC-HPLC after 18 h showed almost quantitative conversion of the starting material.

[1675] At this time, the reaction mixture was filtered to separate the solids, and the filtrate was concentrated under reduced pressure at 60 ° C to an oil. The oil was redissolved in a mixture of IPE: water (2: 1, v: v) (6.0 L) and stirred until no solids were present. The phases were separated, and the organic phase was washed with water (2.0 L), NaHCO3 (2%) (2×2.0 L), brine (1.5 L), and dried over anhydrous Na2SO4. The solvent was then evaporated under reduced pressure at 40 ° C to give a light yellow oil. The oil was dried at room temperature under high vacuum for 18 hours to give 235 g of a slightly white solid. (HPLC purity: 98.3%, ESI-MS: m / z=178.07 / 180.05 [M-Boc+H + ] + The crude product (225 g) was diluted with heptane (1500 mL) at 50°C. The product solution was cooled to 0°C to 5°C in an ice-water bath. A thick suspension slowly formed. The suspension was stirred at 0°C to 5°C for 30 minutes and filtered through a 3-pore glass filter to isolate the product. The filter cake was then dried under vacuum at 35°C to yield 208.0 g of a white solid. (HPLC: 98.6%, yield: 76.2%).

[1676] Example III-4c: Synthesis of H-Abu(4-Cl)-OAll x HCl

[1677]

[1678] To a round-bottom flask containing Boc-Abu(4-Cl)-OAll (208 g, 748.9 mmol) with overhead stirring was added 4N HCl in dioxane (1.5 L) pre-cooled at 4 ° C. The reaction mixture was stirred while it was warmed to room temperature. TLC-IPC after 60 minutes showed that the reaction was complete. At this point, the solvent was evaporated under reduced pressure at 35 ° C. The product precipitated during the concentration process. The solid was redissolved in dioxane (0.5 L) and the solvent was evaporated under reduced pressure again at 35 ° C until the product began to precipitate. IPE (3.5 L) was added and the suspension was stirred in an ice-water bath for 30 minutes. The product was then separated by filtration, the filter cake was washed with IPE (2×200 mL), and the product was dried under vacuum at 35 ° C for 18 hours to obtain 158.5 g of white solid (98.9%).

[1679] Example III-4d: Synthesis of Boc-D-Arg(Pbf)-Abu(4-Cl)-OAll

[1680]

[1681] To a stirred solution of Boc-D-Arg(Pbf)-OH (400.0 g, 91% assay, 691.16 mmol, 1.0 equiv), HD-Abu(4-Cl)-OH (148.0 g, 99.4% assay, 691.16 mmol, 1.0 equiv) in DMF:AcN (1:4, v:v) (2.5 L) at 2°C was added DIPEA (268.0 mL, 2073.48 mmol, 3.0 equiv) followed by TBTU (233.0 g, 725.72 mmol, 1.05 equiv) and the reaction mixture was stirred at 2°C for 10 minutes, warmed to 25°C over 30 minutes and stirred at this temperature. IPC-HPLC after 8 hours showed the reaction was complete (SM: ≤0.1%). The reaction mixture was cooled to 0°C and stirred for 12 hours (overnight). The solvent was evaporated under reduced pressure at 40°C until no more solvent distillate was observed, and the residue was absorbed in EtOAc (12.0L). The organic phase was washed with 5% NaHCO3 aqueous solution (6L), 5% NaHCO3 aqueous solution: brine (5:1, v:v) (6L), brine (5L), and dried over anhydrous Na2SO4. The organic phase was concentrated by evaporation under reduced pressure to obtain an oily substance, and the residue was absorbed in MTBE (1.0L). The product was precipitated by slowly adding the concentrated product solution to IPE: heptane (1:1, v:v) (10.0L) at 0°C to 5°C. The white suspension formed was stirred at 0°C to 5°C for 15 minutes, and the product was isolated by filtration through a 3-pore glass filter. The filter cake was washed with IPE: heptane (1:1, v:v) (2 × 250mL) and dried under vacuum at 35°C to obtain 470.0g of white solid. (HPLC purity: 96.6%, (Boc-D-Arg(Pbf)-Hse(lactone):

[1682] 1.4%, ESI-MS: 686.48 (M+H + ) + , yield: 99.1%).

[1683] Example III-4f: Synthesis of HD-Arg(Pbf)-Abu(4-Cl)-OAllx HCl

[1684]

[1685] To a stirred solution of Boc-D-Arg(Pbf)-Abu(4-Cl)-OAll (220.0 g, 320.6 mmol, 1.0 equivalent) in EtOAc (550 mL) was added 4N HCl in EtOAc (1.65 L) pre-cooled at 0 to 5 ° C, and the reaction mixture was stirred at 0 to 5 ° C. IPC-HPLC after 2 hours showed that the reaction was complete. IPE (6.0 L) was added and the formed suspension was stirred at 0 to 5 ° C for 15 minutes. The product was isolated by filtration, the filter cake was washed with IPE (2 × 500 mL), and dried under reduced pressure at 35 ° C to give 199 g of a white solid. (HPLC purity: 95.2%, yield: 99.7%).

[1686] Example III-4g: Synthesis of Ac-D-Arg(Pbf)-Abu(4-Cl)-OAll

[1687]

[1688] At 20 ℃ to 25 ℃, to a stirred solution of HD-Arg (Pbf) -Abu (4-Cl) -OAll x HCl (380.0 g, 610.34 mmol, 1.0 equivalent) in MeOH (4.0 L), acetic anhydride (86.6 mL, 915.5 mmol, 1.5 equivalents) and 2,4,6- trimethylpyridine (166.4 mL, 1373.3 mmol, 2.25 equivalents) were added, and the reaction mixture was stirred at 20 ℃ to 25 ℃. IPC-HPLC after 1 hour showed that the reaction was complete. The solvent was evaporated under reduced pressure at 40 ℃, and the residue was absorbed in EtOAc (6.0 L). The white suspension formed was stirred at room temperature for 5 to 10 minutes, and the solid was separated by filtration. The filtrate was then washed with NaHSO4 (5% aqueous solution) (2 × 3.0 L), NaHCO3 (5% aqueous solution) (2 × 3.0 L), brine (3.0 L), and dried over anhydrous Na2SO4. The solvent was evaporated under reduced pressure at 40 ° C to give an oily substance, which was absorbed in a mixture of EtOAc: MtBE (1: 1, v: v) (1 L). The product was precipitated by slowly adding the concentrated product solution to IPE: heptane (1: 1, v: v) (12 L) at 0 ° C to 5 ° C. The formed suspension was stirred at 0 ° C to 5 ° C for 30 minutes and the product was isolated by filtration through a 3-pore glass filter. The filter cake was then washed with IPE: heptane (1: 1, v: v) (2 × 0.5 L) and dried in vacuo at 35 ° C to give 320.0 g of a white solid (HPLC purity: 96.0%, ESI-MS: m / z = 628.3 [M + H + ] + , yield: 83.5%).

[1689] Example III-4h: Synthesis of Ac-D-Arg(Pbf)-Abu(4-(S)-Cys-OMe)-OAll (structural unit)

[1690]

[1691] Prepare a solution of Ac-D-Arg(Pbf)-Abu(4-Cl)-OAll (180.0 g, 286.5 mmol, 1.0 equiv) and H-Cys-OMex HCl (123.0 g, 716.3 mmol, 2.5 equiv) in degassed DMSO (0.5 L) (Sln A). At 23 ± 2 ° C, this solution was added to a stirred suspension of CsCO (280.1 g, 859.6 mmol, 3.0 equiv) and degassed DMSO (0.4 L) over 1 hour. After completing the addition of Sln A for 2 hours, IPC-HPLC showed that the reaction was complete. The reaction mixture was added to a mixture of Me-THF:NaHCO (5%, aqueous solution): saline (6:3:1, v:v:v) (15 L) and stirred for 5 to 10 minutes. The phases were separated, and the organic phase was washed with NaHCO (5% aqueous solution): brine (3:1, v:v) (6.0 L) and brine (4.0 L). The aqueous phase of the first wash was extracted with MeTHF (2 x 3.0 L), and the organic phase was combined with the original phase and dried over anhydrous NaSO. The solvent was then evaporated under reduced pressure at 40°C to approximately 0.9 L. This solution was added to IPE (9.0 L). The product precipitated. The solid was filtered, and the filter cake was washed with IPE (2 x 0.5 L) and dried under vacuum at 35°C to yield 166.0 g of a white solid (HPLC purity: 91.5%, yield: 79.7%).

[1692] 218g of the crude product was dissolved in THF (1.5kg) at 40°C. The solution was cooled to 0°C within 40 minutes and stirred at this temperature for 30 minutes. IPE (0.5kg) was added at 0°C within 30 minutes and the resulting suspension was stirred at 0°C for another hour. The product was separated by filtration through a 3-pore glass filter, and the filter cake was washed with -5°C pre-cooled THF:IPE (3:1, ww) (2×300mL) and dried in vacuo at 35°C for 18 hours to give 192g of a white solid. HPLC purity: 96.9%, ESI-MS: m / z=727.53 [M+H + ] + , yield: 88.0%.

[1693] Example III-5: Synthesis of ring fragments

[1694]

[1695] Example III-5a: Synthesis of Z-Trp-Gln(Trt)-OMe

[1696]

[1697] In a flask, H-Gln(Trt)-OMe (4.00 g / 1.00 equiv) and Z-Trp-OH (3.36 g / 1.00 equiv) were dissolved in DMF (40 mL). To the clear yellow solution was added NMM (4.37 mL / 4.00 equiv) at room temperature. The solution was cooled to 0°C in an ice bath and TBTU (3.51 g / 1.10 equiv) was added in one portion. The reaction mixture was stirred at 0°C for 2 hours and then warmed to room temperature. HPLC-2 (18 hours): 90.7% product; no H-Gln(Trt)-OMe detected; 5.4% Z-Trp-OH. The resulting yellow solution (reaction mixture) was precipitated with 450 mL of aqueous NaHCO3 (2%). The suspension was filtered and washed with aqueous NaHCO3 (5%) (4 x 25 mL) and water (4 x 25 mL). The product was dried in a vacuum oven at 45°C under reduced pressure to give 7.34 g of crude product (102%).

[1698] The product was recrystallized by adding MTBE (425 mL) to the crude product (7.34 g). The suspension was stirred at 40° C. The product partially dissolved in the solvent, but crystallization began at the same time. A fine white suspension was obtained, which was stirred at 40° C. for 30 minutes. The suspension was stirred at 10° C. for 1 hour. The suspension was filtered and washed with MTBE (2×25 mL). The product was dried under reduced pressure in a vacuum oven at 45° C. to obtain 6.75 g (98%) of product.

[1699] Example III-5b: Synthesis of H-Trp-Gln(Trt)-OMe*HCl

[1700]

[1701] In a hydrogenation reactor (20 L), Z-Trp-Gln(Trt)-OMe (625.8 g / 1.00 eq) was suspended in MeOH / H2O (10.0 L; 95 / 5). Pd / C 5% (47.0 g) and HCl 36.4% (77.4 mL / 1.05 eq) were added. The suspension was hydrogenolyzed at 30° C. and 2.5 bar H2 pressure. The reaction mixture was clarified by filtration and washed with MeOH (2×500 mL). The filtrate was stored at 5° C. overnight. The thick orange filtrate was evaporated under reduced pressure at 45° C. to an orange solution (9.0 L distillate). EtOAc (3×1.0 L) was added, evaporated again to an orange solution (3.0 L distillate), and then evaporated to a thick oil (followed by azeotropic distillation of EtOAc 2×1.0 L). EtOAc (3.0 L) was added and the reaction mixture was precipitated by adding IPE (9.0 L). The pink suspension was filtered and washed with IPE (3 x 1.0 L). The product was dried in a vacuum oven at 40°C to give 556.8 g / 103% product.

[1702] Example III-5c: Synthesis of Z-Thr(tBu)-OH

[1703]

[1704] In a 10L flask, Z-Thr(tBu)-OH*DCHA (400.0g) was suspended in EtOAc (3L) and water (1L): a viscous white suspension was formed. Under vigorous stirring, the pH was adjusted to 1.5 to 2 with sulfuric acid (10% about 1.1L). After stirring the mixture for 10 minutes, a clear solution was formed. The layers were separated and the organic layer was washed with water (3×1.5L). The organic layer was evaporated under reduced pressure at 40°C to obtain an oil. The residual oil was diluted with EtOAc (1L) and concentrated under reduced pressure at 40°C to an oil. The residual oil was diluted with EtOAc (1L) and concentrated under reduced pressure at 40°C to an oil. The oil was dissolved with DMF (1L). The product solution was evaporated under reduced pressure at 40°C for 15 minutes to remove residual EtOAc, obtaining 616.8g / 100%.

[1705] Example III-5d: Synthesis of Z-Thr(tBu)-Trp-Gln(Trt)-OMe

[1706]

[1707] In a 10 L reactor, H-Trp-Gln(Trt)-OMe*HCl (517.0 g / 1.00 equiv), Z-Thr(tBu)-OH oil 41.3% (596.3 g / 0.96 equiv) and Z-Thr(tBu)-OH oil 46.6% (20.5 g / 0.04 equiv) were dissolved in DMF (synthetic mass (5.0 L)). The mixture was stirred at 20 ° C for 15 minutes until a red solution was formed. The solution was cooled to 0 ° C with a jacket temperature of -5 ° C. TBTU (292.1 g / 1.10 equiv) was added in one portion. The jacket temperature was raised to 0 ° C. NMM (273 mL / 3.00 equiv) was added dropwise over 2 hours. The reaction mixture was stirred at a jacket temperature of 0 ° C for another 2 hours (pH = 5.5). At first, the jacket temperature is warming up to 5 ℃, then it is warming up to 15 ℃ after 1 to 2 hours, and the reaction mixture is stirred overnight. The reaction mixture is evaporated under reduced pressure at 65 ℃ until DMF is almost completely removed to obtain a red to light yellow oily substance. The remaining oily substance is dissolved among EtOAc (2.5L). The organic layer is washed with NaHCO solution (2%, 3 × 1.5) and water (3 × 2L). The organic layer is evaporated under reduced pressure at 40 ℃ to become an oily substance and is dried by azeotropic distillation with EtOAc (2 × 1L). At 40 ℃, the remaining oily substance is dissolved among MeTHF (1.5L).

[1708] The MeTHF solution was diluted with IPE (approximately 1 L) until turbidity was observed and stirred at 20°C for 68 hours: an oil formed. The solvent was evaporated at 40°C and redissolved in MeTHF (1.5 L) (approximately 2 L solution). This solution was added to IPE (12 L) at room temperature over 50 minutes: a light yellow fine suspension formed. The suspension was stirred at room temperature (18°C to 20°C) for 1 hour. The suspension was filtered and washed with IPE (3 x 1.5 L). The product was dried in a vacuum oven at 40°C to yield 630.6 g / 87% product.

[1709] Example III-5e: Synthesis of H-Thr(tBu)-Trp-Gln(Trt)-OH

[1710]

[1711] In a 20 L hydrogenator, Z-Thr(tBu)-Trp-Gln(Trt)-OMe (607.0 g / 1.0 eq) was dissolved in MeOH / H2O (9 / 1; 6070 mL). Pd / C 5% (67.0 g) was added. Hydrogenolysis was initiated at 25°C / 3.0 bar H2 pressure. After 5 hours, the hydrogenolysis was stopped. The catalyst was filtered off and washed with methanol (2 x 200 mL). The pale yellow solution was evaporated under reduced pressure to a paste (methanol removed). The viscous solution was dissolved in THF (4.2 L) and water (1.2 L). The mixture was stored at 5°C overnight. After warming to 15°C, a clear solution was obtained. To this mixture, a solution of LiOH*H2O (43.3 g / 1.50 eq) in water (1.77 L) was added at 5°C over 3 hours. The solution was stirred for a further 1 hour at 5°C. Methanol (3 L) was then added and the yellow solution was heated to 20°C. The pH was adjusted to 7.0 with 10% HCl (320 mL). The yellow solution was converted into a suspension and stirred at 20°C for 1 hour. The suspension was filtered and washed with methanol (3 x 1 L). The product was dried in a vacuum oven at 40°C to give 486.9 g / 96.5%.

[1712] Example III-5f: Synthesis of Fmoc-Gln-ONp

[1713]

[1714] In a 10L reactor, Fmoc-Gln-OH (600.0g / 1.00 equivalent) and 4-nitrophenol (226.6g / 1.00 equivalent) were suspended in DMF (6L). The suspension was heated to 35°C and stirred for 1 hour. Then another portion of DMF (2L) was added and stirred for 20 minutes to form a clear yellow solution. The solution was cooled to -5°C and a solution of DCC (370g / 1.10 equivalent) in DMF (2L) was added dropwise from 0°C to -5°C over 3 hours. The dilute yellow suspension was stirred at 0°C overnight. The reaction mixture was slowly heated to room temperature during stirring. It was then clarified and filtered and washed with DMF 2×1L. The filtrate was precipitated in water (35L) and a light yellow suspension was formed. The suspension was filtered and washed with water (3×6.5L) and IPE (3×5L). The product was dried in a vacuum oven at 40°C to obtain 870 g of product.

[1715] Example III-5g: Synthesis of Fmoc-Gln-Thr(tBu)-Trp-Gln(Trt)-OH (ring fragment)

[1716]

[1717] In a 10 L reactor, Fmoc-Gln-ONp (210.7 g / 0.90 equivalents) was dissolved in DMF (synthetic quality, 2 L) to form a clear, colorless solution. In a flask, H-Thr(tBu)-Trp-Gln(Trt)-OH (350 g / 1.0 equivalents) was suspended in DMF (synthetic quality, 3.5 L). Trimethylpyridine (202.8 g / 3.50 equivalents) was added. The suspension was stirred at 45 ° C for 45 minutes to form a turbid solution. The yellow dilute suspension was added to the Fmoc-Gln-ONp solution at 22 ° C over 6.75 hours and stirred at room temperature overnight. The reaction mixture was divided into two parts (3 L). The first part (3 L) was diluted with EtOAc (4.5 L) and NaHSO4-5% (5 L). The phases were separated and the aqueous phase was extracted with EtOAc (2.7 L). The second portion was treated in the same manner. The combined organic phases were washed with water (4 x 1.5 L). The organic layer was evaporated under reduced pressure at 45°C to a dilute suspension of about 5 L. The mixture was co-distilled again with EtOAc (5 x 3 L) to a 5 L residue. The dilute suspension was stirred in an ice bath for 30 minutes, filtered and washed with EtOAc (3 x 1 L). The product was dried in a vacuum oven at 40°C to give 366.8 g / 71% product.

[1718] The crude product was dissolved in EtOAc (5.7 L), DMF (980 mL) and water (350 mL). After stirring at room temperature for 30 minutes, a clear yellow solution was formed. The solution was washed with NaCl-10% solution (2 × 1.0 L) and water (2 × 1.0 L). The organic phase was diluted with EtOAc (2.0 L) and evaporated under reduced pressure at 45 ° C. After 2.0 L of distillate, the dilute suspension was co-distilled with EtOAc (3 × 1.5 L). During the evaporation process, the product crystallized into a white suspension. The suspension was stirred in an ice bath for 1 hour and filtered. The filter cake was washed with EtOAc (4 × 0.60 L). The product was dried in a vacuum oven at 40 ° C. The product was dried in a vacuum oven at 40 ° C to obtain 356.90 g / 69% product.

[1719] Example III-6: Synthesis of Fragment 1

[1720] Example III-6a: Coupling of Fmoc-Gln(Trt)-Thr(tBu)-Gln(Trt)-OH and Ac-D-Arg(Pbf)-Abu(4-(S)-Cys-OMe)-OAll

[1721]

[1722] To a solution of Ac-D-Arg(Pbf)-Abu(4-(S)-Cys-OMe)-OAll (1.12 g, 1.54 mmol, 1.02 equiv), Fmoc-Gln(Trt)-Thr(tBu)-Trp-Gln(Trt)-OH (2.0 g, 1.15 mmol, 1.0 equiv), and 2,4,6-trimethylpyridine (0.796 mL, 6.04 mmol, 4.0 equiv) in acetonitrile (40 mL) was added PyAOP (0.905 g, 1.74 mmol, 1.15 equiv), and the reaction mixture was stirred at 20°C. After 16 h, HPLC-IPC showed that the reaction was almost complete (BB: 0.6%, FG1 ring: 0.2%). The solvent was evaporated under reduced pressure at 35°C, and the residue was taken up in EtOAc (100 mL). The organic phase was washed with NaHSO4 (5% aqueous solution) (50 mL), NaHCO3 (5% aqueous solution) (50 mL), NaHCO3 (5% aqueous solution): brine (3: 1) (60 mL), brine (50 mL) and dried over anhydrous MgSO4. The product solution was concentrated to 20 mL and the product was precipitated by adding the concentrated solution to IPE (200 mL) at 0°C to 5°C. The formed white suspension was stirred at 0°C to 5°C for 10 minutes and the product was isolated by filtration through a 3-pore glass filter. The filter cake was washed with IPE (2×10 mL) and dried under reduced pressure at 35°C to give 3.12 g of a white solid (HPLC purity: 81.5%, ESI-MS: m / z=1972.59 [M-Trt+H + ] + ,m / z=1018.45[M+2H + ] 2+ , yield: 101.4%).

[1723] Example III-6b: Allyl ester and Fmoc cleavage

[1724]

[1725] To a solution of Fmoc-Gln(Trt)-Thr(tBu)-Trp-Gln(Trt)-Cys-OMe-((S)-4-Abu-D-Arg(Pbf)-Ac)-OAll (2.9 g, 1.421 mmol, 1.0 equiv) and phenylsilane (1.75 mL, 0.14.21 mmol, 10.0 equiv) in anhydrous THF (30.0 mL) was added Pd(PPh 3 ) 4 (0.082 g, 0.071 mmol, 0.05 equiv) and the reaction mixture was stirred at room temperature. The reaction was completed (IPC-HPLC: SM: not detected). The product was then precipitated by adding the reaction mixture to IPE (300 mL) at 0° C. to 5° C. The formed suspension was stirred at 0° C. to 5° C. for 10 minutes and the product was isolated by filtration. The filter cake was washed with IPE (3×10 mL) and dried in vacuo at 35° C. to obtain 2.67 g of a gray solid. (HPLC purity: 84.6%, ESI-MS: m / z=1993.97 [M+H + ] + , yield: 97.2%).

[1726] Fmoc deprotection: To a solution of Fmoc-Gln(Trt)-Thr(tBu)-Trp-Gln(Trt)-Cys-OMe-((S)-4-Abu-D-Arg(Pbf)-Ac)-OH (2.5 g, 1.293 mmol, 1.0 equiv) in DMF (25 mL) was added DBU (0.25 mL, 1% v:v) at room temperature and the reaction mixture was stirred at room temperature. IPC-HPLC after 180 minutes indicated the reaction was complete (SM: not detected). The solvent was evaporated under reduced pressure at 40°C to give an oil, which was taken up in EtOAc (100 mL) to form a suspension. The suspension was diluted with IPE (200 mL) and stirred at room temperature for 10 minutes. The product was then isolated by filtration, washed with IPE (2×10 mL) and dried under reduced pressure at 35° C. to give 2.28 g of a pale yellow solid (HPLC purity: 82.5%, ESI-MS: m / z=1771.83 [M+H + ] + , yield: 90.6%).

[1727] Example III-6c: Cyclization of linear precursors

[1728]

[1729] Prepare the following solutions:

[1730] Sln.A: The linear protected peptide (1.2 g, 0.678 mmol, 1.0 eq) and DIPEA (0.461 mL, 2.71 mmol, 4.0 eq) were dissolved in 20 mL of DMF.

[1731] Sln.B.: PyOxim (0.536 g, 1.016 mmol, 1.5 eq.) and 30 mL of DMF were dissolved in a 100 mL reaction vessel at room temperature.

[1732] Sln.A was added to Sln.B at room temperature over 2.0 hours. The final concentration was 13.5 mM. 30 minutes after the addition of Sln.B was completed, a sample was taken to HPLC-IPC to determine that the reaction was complete. (SM: not detected). The solvent was evaporated to an oil at this time, and the oil was redissolved in EtOAc (100 mL). The organic phase was washed with 5% NaHCO3 (2×50 mL), brine (50 mL) and dried over anhydrous Na2SO4. The solvent was evaporated under reduced pressure at 35°C to obtain an oil. The product was precipitated by adding the oil to IPE: heptane (1:1, v:v) (200 mL), separated by filtration through a 3-pore glass filter and dried in vacuo at 35°C for 18 hours to obtain 1.11 g of a slightly white solid. (HPLC purity: 81.3%, ESI-MS: 1753.85 [M+H + ] + , yield: 92.6%).

[1733] Example III-6d: Deprotection of methyl ester

[1734]

[1735] To a solution of the cyclic peptide prepared in Example III-6c (3.6 g, 2.383 mmol, 1.0 equiv) in THF:water (3:1, v:v) (40 mL) was added LiOH x HO (0.198 g, 4.71 mmol, 2.0 equiv) and the reaction mixture was stirred at room temperature. IPC-HPLC after 1 hour indicated the reaction was complete (SM: not detected). At this point, the solvent was evaporated and the residue was taken up in MeTHF (50 mL) and stirred until a fine suspension formed. 5% NaHSO (40 mL) was added and the mixture was stirred until a clear two-phase solution was obtained. The phases were separated and the organic phase was washed with water (40 mL), brine (40 mL), and dried over anhydrous sodium sulfate. The solvent was evaporated to approximately 15 mL and the product was precipitated by adding the product solution to IPE (150 mL). The product was then isolated by filtration, and the filter cake was washed with IPE (2×10 mL) and dried under vacuum at 35°C to yield 3.2 g of a slightly off-white solid. (HPLC purity: 82.2%, ESI-MS: m / z=1496.91 [M+H + ] + , yield: 90.8%).

[1736] Synthesis of Example III

[1737] Example III-7: Coupling Fragment 1 and Fragment 2+3 to Prepare Protected Example III

[1738]

[1739] Fragment 1 (2.745 g; 1.00 eq) and fragment 2+3 (2.369 g; 0.99 eq) were dissolved in DMF (synthesis mass, 28 mL). The yellow solution was cooled in an ice bath, TBTU (0.620 g; 1.05 eq) was added, followed by DIPEA (936 μL), and the reaction mixture was stirred at 0° C. for 1 hour. The mixture was then further stirred at room temperature, additional fragment 2+3 (24 mg / 0.01 eq) and TBTU (29 mg / 0.05 eq) were added and stirred overnight. The reaction mixture was precipitated in NaHCO 3 -2% (280 ml) and stirred for 5 minutes. The white suspension was filtered and washed with water (3×25 mL). The protected Example III product was dried in a vacuum oven at 40° C. to give 4.435 g / 87% ESI-MS: [M+2H] 2+ :1392.10.

[1740]

[1741] The protected Example III (1.000 g) was dissolved in HFIP (30.0 mL) in a flask. The slightly turbid solution was clarified by filtration and washed with HFIP (6.0 mL). TIS (400 μL) and DODT (400 μL) were added to the clear orange solution. The solution was stirred at 22° C. and an aqueous HCl solution (36%, 4.00 mL) was added in two portions over 2 minutes. The solution was stirred at 22° C. After stirring for 1 hour and 15 minutes, the reaction mixture was precipitated by adding IPE (1000 mL). The product was washed three times with IPE. The product was dried in a vacuum oven at 40° C. to give 675.4 mg / 99% of Example III.

[1742] Alternatively, the protected Example III was converted to Example III using the following method: In a flask, the protected Example III (11.33 g) was dissolved in HFIP (368.0 mL). The slightly turbid solution was clarified by filtration and washed with HFIP (40.0 mL). TIS (4.53 mL) and DODT (4.53 mL) were added to the clear orange solution. The solution was stirred at 23 ° C, and HCl (36%, 45.00 mL) was added within 2 minutes. The solution was stirred at 22 ° C. After stirring for 45 minutes, the reaction mixture was precipitated by adding IPE (10.0 L). The beige suspension was stirred for 5 minutes, then filtered and washed with IPE (5×100 mL). The product was dried in a vacuum oven at 35 ° C to provide 7.992 g / 103% (not measured) MS: [M+2H] 2+ :917.45; [M+H]+:1834.26. The product was purified using semi-preparative HPLC on a Daisopack SP-100-8-C8-PK (250×20 mm) column, with gradient elution using water and MeOH+0.2% AcOH as eluents. Fractions with HPLC purity ≥98.0% from all batches were combined and concentrated to half the volume in vacuo at 35°C. The product solution was then injected into a Daisopack SP-100-8-C8-PK (250×20 mm) column, and the column was washed with 0.2M ammonium acetate (100 mL) and an aqueous solution of 5% acetonitrile+0.2% AcOH (100 mL). The product was finally eluted with 25% acetonitrile aqueous solution+0.2% AcOH. The fraction of interest was tested by analytical HPLC (IPC-HPLC ≥98.0%). The fractions that completed IPC-HPLC were combined, diluted with water (1:1), frozen and lyophilized to give 0.46 g of product as a white powder (HPLC purity: 98.9%, ESI-MS: m / z = 917.38 [M+2H + ] + ).

[1743] At 35 ℃, the protected embodiment III (1.5g) was dissolved in a mixture of water and IPA (9.9mL, 1:1v / v). 130μl water was then added. The solution was cooled to 23 ℃ and seed crystals (10mg) were added in 20 minutes. The mixture was then stirred at 23 ℃ for 2 hours, cooled to 5 ℃ with 0.1K / min, stirred at 5 ℃ for 3 hours, warmed to 22 ℃ in 30 minutes, stirred at 22 ℃ for 3 hours, cooled to 5 ℃ with 0.1K / min, and stirred at 5 ℃ for 9 hours. The suspension was then filtered, washed with a mixture of water and IPA (1.5mL, precooling, 1:1, v / v), washed subsequently with IPA (0.75mL), and dried under vacuum at 40 ℃ overnight to obtain 603mg embodiment III (HPLC purity: 92.8%).

[1744] The following reaction schemes may aid in understanding the reactions discussed throughout the following examples.

[1745] Reaction Scheme IV-1

[1746] The following reaction schemes (Schemes IV-1 to IV-3) are intended only to represent examples of the present invention and are in no way intended to limit the present invention. The following liquid phase synthetic route to compound 26 was developed.

[1747] Compound 26

[1748]

[1749] Compound 26 can be prepared by a convergent liquid-phase peptide synthesis method, as shown in Schemes IV-1, IV-2, and IV-3. In this method, the target molecule is constructed by condensing a cyclic N-terminal heptapeptide fragment with a hexapeptide C-terminal peptide fragment.

[1750] • To this end, a suitably protected tyrosine derivative residue (Pos7) can be reacted with a suitably protected penicillamine residue (Pos6) to form the dipeptide (7).

[1751] • The dipeptide (7) can be deprotected at the terminal amine and reacted with a suitably protected lysine derivative residue (Pos5) to form the tripeptide (9).

[1752] • The tripeptide (9) can be deprotected at the terminal amine and reacted with a suitably protected tryptophan derivative residue (Pos4) to form the tetrapeptide (11).

[1753] • Tetrapeptide (11) can be deprotected at the terminal amine to form compound (20).

[1754] • A suitably protected threonine derivative residue (Pos3) can be reacted with a suitably protected asparagine residue (Pos2) to form a dipeptide (1).

[1755] • The dipeptide (1) can be deprotected at the terminal amine and reacted with a suitably protected penicillamine (Pos1) to form the tripeptide (3).

[1756] • Tripeptide (3) can be deprotected at the terminal amine and reacted with a suitable acylating agent to form compound (5), which can be deprotected at the C-terminus to form compound (6).

[1757] • Peptide fragments (6) and (20) are coupled together via a suitable coupling reagent to form peptide fragment (21).

[1758] • The peptide fragment (21) can be deprotected at the C-terminus to form the peptide fragment (22).

[1759] • The peptide fragment (22) can be converted into a cyclic peptide fragment (23).

[1760] • A suitably protected sarcosine derivative residue (Pos13) can be reacted with a suitably protected 3-pyridyl-alanine derivative residue (Pos12) to form a dipeptide (12).

[1761] • The dipeptide (12) can be deprotected at the terminal amine and reacted with an appropriately protected asparagine derivative residue (Pos11) to form the tripeptide (14).

[1762] • The tripeptide (14) can be deprotected at the terminal amine and reacted with an appropriately protected glutamic acid derivative residue (Pos10) to form the tetrapeptide (16).

[1763] • Tetrapeptide (16) can be deprotected at the terminal amine to form compound (17).

[1764] • A suitably protected tetrahydropyran-glycine derivative residue (Pos9) can be reacted with a suitably protected naphthyl-alanine derivative residue (Pos8) to form a dipeptide (18).

[1765] • The dipeptide (18) and compound (17) can be coupled together via a suitable coupling reagent to form the peptide fragment (19).

[1766] • Peptide fragment (19) can be deprotected at the terminal amine to form peptide fragment (24).

[1767] • Peptide fragments (23) and (24) are coupled together via a suitable coupling reagent to form a protected peptide intermediate (25), which is subsequently deprotected to form compound 26.

[1768]

[1769] Scheme IV-1 Reaction Scheme IV-2

[1770]

[1771] Reaction Scheme IV-3

[1772]

[1773] Example IV-1: Synthesis of Cbz-[2-3]-OMe (Cbz-Asn-Thr(tBu)-OMe)

[1774]

[1775] To a solution of Z-Asn-OH (500.00 g, 1.877 mol, 1.0 equiv), H-Thr(tBu)-OMe (445.06 g, 1.971 mol, 1.05 equiv) and Oxyma Pure (266.85 g, 1.877 mol, 1.0 equiv) in EtOAc:DMSO (1:1, v:v) (3 L) was added triethylamine (572.6 mL, 4.311 mol, 2.2 equiv) and the mixture was stirred at 25° C. to 30° C. for 10 minutes. EDC x HCl (468.00 g, 2.441 mol, 1.3 equiv) was added to the reaction mixture in four portions over 1 hour and stirred overnight until the reaction was complete.

[1776] The reaction mixture was then diluted with EtOAc (6 L) and washed with NaHSO (5% aqueous solution) (2 x 5 L), NaHCO (5% aqueous solution) (4 x 5 L) and water (5 L). The organic layer was evaporated under reduced pressure at 40 ° C, and the residue was co-evaporated with EtOAc (3 x 3 L). The residue (approximately 25% w / v) was cooled to 20 ° C and seeded with crystals. The product crystallized and the resulting suspension was stirred at 0 ° C to 5 ° C for 2 hours, and then the product was isolated by filtration. The filter cake was washed with pre-cooled EtOAc (3 x 1 L) and the product was dried under reduced pressure at 30 ° C overnight to obtain 653 g (80% yield, 99% HPLC purity) of the desired product (Cbz-[2-3]-OMe) as a white solid.

[1777] Example IV-2: Catalytic hydrogenolysis to produce H-[2-3]-OMe (H-Asn-Thr(tBu)-OMe)

[1778]

[1779] Z-Asn-Thr(tBu)-OMe (330.0 g, 0.754 mol, 1.0 equiv) and EtOAc (2.6 L) were charged to a hydrogenation reactor and the mixture was stirred until a clear solution was obtained. Pd(OH)2 on activated carbon (6.6 g, 2% (w:w)) was added, the reactor was closed under nitrogen, and the temperature was set at 40°C. Hydrogen pressure (3 bar) was applied and the reaction mixture was stirred until the reaction was complete. The reaction mixture was cooled to 25°C and filtered through a depth filter to remove the catalyst and stored at 4°C overnight (mass: 2.46 kg).

[1780] Example IV-3: Synthesis of Fmoc-[1-3]-OMe (Fmoc-Pen(Trt)-Asn-Thr(tBu)-OMe)

[1781]

[1782] A 15 L glass reactor with an overhead stirrer was charged with Fmoc-Pen(Trt)-OH (387.0 g, 0.628 mol, 1.0 equiv), TBTU (216.2 g, 0.673 mol, 1.07 equiv), DMSO (0.6 L) and the solution obtained in the above step (2.3 kg, 200.0 g H-Asn-Thr(tBu)-OMe, 0.659 mol, 1.05 equiv). The reaction mixture was stirred at 22 ° C until a clear solution was formed, and DIPEA (305.2 mL, 1.795 mol, 2.0 equiv) was immediately added. The reaction mixture was stirred at 20 ° C to 25 ° C for 1 hour until the reaction was complete.

[1783] The reaction mixture was diluted with EtOAc (2.0 L) and washed with NaHCO3 (5% aqueous solution) (3 x 3 L) and water (2 x 3 L). The solvent of the organic phase was evaporated under reduced pressure at 35° C. and the residue was co-evaporated with EtOAc (2 x 2.5 L).

[1784] The residue is placed in EtOAc (3.0 L) and the product is precipitated by slowly adding the product solution into heptane (30 L). The white suspension formed is stirred at 20 ℃ to 25 ℃ for 30 minutes, and then the product is isolated by filtration. The filter cake is washed with heptane (2 × 2 L) and dried under vacuum at 35 ℃ for 18 hours to obtain 545 g (97% yield, 99% HPLC purity) of the required product as a white solid.

[1785] Example IV-4: Synthesis of H-[1-3]-OMe (H-Pen(Trt)-Asn-Thr(tBu)-OMe)

[1786]

[1787] A 15 L glass reactor with an overhead stirrer was charged with Fmoc-Pen(Trt)-Asn-Thr(tBu)-OMe (500.0 g, 0.556 mol, 1.0 eq) and EtOAc:DMSO (9:1, v:v) (5.0 L). The reaction mixture was stirred at 22° C. until a clear solution formed. DBU (24.9 mL, 0.167 mol, 0.3 eq) was added and the reaction mixture was stirred at 20° C. to 25° C. for 90 minutes until the reaction was complete.

[1788] The reaction mixture is diluted with EtOAc (4.0L) and washed with NaHCO (5% aqueous solution) (4L) and water (4L). The solvent of the organic phase is evaporated under reduced pressure at 40°C, and the residue is co-evaporated with EtOAc (2 × 2.0L). Residue is placed in EtOAc (2.0L), and the product is precipitated by adding the product solution into heptane (30L). The white suspension formed is stirred 15 minutes at 20°C to 25°C, and the product is then separated by filtration. The filter cake is washed with heptane (2 × 2L), and dried under vacuum at 35°C for 18 hours to obtain 337g (90% productive rate, 94% HPLC purity) required product as a white solid.

[1789] Example IV-5: Synthesis of Ac-[1-3]-OMe (Ac-Pen(Trt)-Asn-Thr(tBu)-OMe)

[1790]

[1791] A 15 L glass reactor with an overhead stirrer was charged with H-Pen(Trt)-Asn-Thr(tBu)-OMe (318.2 g, 0.470 mol, 1.0 eq) and MeOH (3.0 L), and the reaction mixture was stirred at 22 ° C until a clear solution was formed. Acetic anhydride (55.6 mL, 0.588 mol, 1.25 eq) was added and the reaction mixture was stirred at 20 ° C to 25 ° C for 1 hour until the reaction was complete. The reaction mixture was concentrated by evaporating the solvent at 45 ° C, and the residue was taken up in EtOAc:Me-THF (1: 1, v: v) (4.0 L). The organic phase was washed with NaHCO (5% aqueous solution) (2 L) and water (2 L), the solvent of the organic phase was evaporated under reduced pressure at 45 ° C, and the residue was co-evaporated with EtOAc (2×1.5 L). The residue was placed in EtOAc (3.0 L) and the product was precipitated by adding the product solution to heptane (30 L). The resulting white suspension was stirred at 20° C. to 25° C. for 15 minutes, and the product was then isolated by filtration. The filter cake was washed with heptane (4×1 L) and dried under vacuum at 35° C. for 18 hours to give 328.2 g (97% yield, 99% HPLC purity) of the desired product as a white solid.

[1792] Example IV-6: Synthesis of Ac-[1-3]-OH (Ac-Pen(Trt)-Asn-Thr(tBu)-OH)

[1793]

[1794] Ac-Pen(Trt)-Asn-Thr(tBu)-OMe (310.0 g, 0.431 mol, 1.0 equiv) and THF (1.5 L) were charged into a 10 L reactor with overhead stirring. The mixture was stirred until a clear solution was obtained. The product solution was diluted with water (1.5 L) and cooled to 5 ° C. A solution of LiOH x H2O (25.35 g, 0.603 mol, 1.4 equiv) in water (0.5 L) was added to the reaction mixture over 90 minutes while stirring at 5 ° C for 5 hours until the reaction was complete. The reaction mixture was diluted with water (1.5 L) and Me-THF (5 L) and the layers were separated. Me-THF (6 L) was added to the aqueous phase and the pH of the two-phase mixture was adjusted to 4.7 with HCl (10%, 100 mL). The phases were separated and the aqueous phase was re-extracted with EtOAc (3.0 L). The two organic phases are mixed, and the solvent is evaporated under reduced pressure at 35 ° C, and the residue is co-evaporated with EtOAc (2 × 3.0L). Residue is placed in EtOAc (3.0L), by adding the product solution into heptane (35L) and precipitating the product. The white suspension formed is stirred at 20 ° C to 25 ° C for 15 minutes, then separated by filtration. The filter cake is washed with heptane (2 × 0.5L), and dried under vacuum at 35 ° C for 18 hours to obtain 252.4g (83% yield, 98% HPLC purity) required product, which is a white solid.

[1795] Example IV-7: Synthesis of Fmoc-[6-7]-OMe (Fmoc-Pen(Acm)-Tyr(2-Boc-ea)-OMe)

[1796]

[1797] Fmoc-Pen(Acm)-OH (0.79 mol, 1.0 equivalent), H-Tyr(2-Boc-ea)-OMe (0.81 mol, 1.02 equivalent) and Oxyma Pure (0.79 mol, 1.0 equivalent) were dissolved in EtOAc (3.5 L). DIC (0.87 mol, 1.1 equivalent) was added at 23 ° C in 2 hours and the reaction was stirred for 1 hour until the reaction was complete. The reaction mixture was filtered and the filter cake was washed with EtOAc. The product solution was washed with NaHSO4 aqueous solution, NaHCO3 aqueous solution and water. The solvent was evaporated under reduced pressure at 35 ° C, and the resulting residue was co-evaporated with EtOAc. The residue was absorbed in Me-THF (2 L), and the product solution was precipitated by adding the solution to pentane (35 L) within 30 minutes. The white suspension was separated by filtration, and the product was washed with pentane. The off-white product was dried in a vacuum oven under reduced pressure at 35°C for 48 hours to afford 637.8 g (106% yield, 94% HPLC purity) of the desired product as an off-white solid.

[1798] Example IV-8: Synthesis of H-[6-7]-OMe (H-Pen(Acm)-Tyr(2-Boc-ea)-OMe)

[1799]

[1800] Fmoc-Pen(Acm)-Tyr(2-Boc-ea)-OMe (0.786 mol, 1.0 equivalent) was dissolved in EtOAc / DMSO (9: 1; v: v) (6 L). DBU (0.393 mol, 0.5 equivalent) was added to the solution. The reaction mixture was stirred at room temperature for 2.5 hours until the reaction was complete. The organic product layer was diluted with EtOAc and washed with 5% NaHCO3 aqueous solution and H2O. The aqueous phase was washed with EtOAc. The organic phases were combined and evaporated at 35°C. The residue was co-distilled twice with EtOAc. The residue was stored at 4°C to 5°C overnight and used directly as the starting material for the following steps (Example 9, synthesis of Fmoc-[5-7]-OMe).

[1801] Example IV-9: Fmoc-[5-7]-OMe (Fmoc-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe) synthesis

[1802]

[1803] To a solution of H-Pen(Acm)-Tyr(2-Boc-ea)-OMe (0.732 mol, 1.0 equiv) in EtOAc / DMSO (8:2; v:v) (3 L) was added Fmoc-Lys(Ac)-OH (0.637 mol, 0.87 equiv) and TBTU (0.696 mol, 0.95 equiv), and the reaction mixture was stirred at room temperature for 2 minutes. DIPEA (1.391 mol, 1.90 equiv) was added and the reaction mixture was stirred at room temperature for 2 hours until the reaction was complete. The reaction mixture was diluted with EtOAc and washed twice with 20% NaHSO4 aqueous solution, H2O, twice with 5% Na2CO3 aqueous solution, and again with water. The aqueous phase was washed with EtOAc. The organic phase was evaporated at 35°C and co-distilled twice with EtOAc. The residue was dissolved in EtOAc. The mixture was slowly added to IPE over 25 minutes. The suspension was filtered and washed three times with IPE. The solid was dried at 35°C under high vacuum overnight. The white solid was dissolved in EtOAC. The solution was added to IPE over 5 minutes. The suspension was filtered and washed three times with IPE. The solid was dried at 35°C under high vacuum overnight to give 554.9 g (76% yield in two steps, 97% HPLC purity) of the desired product as a white solid.

[1804] Example IV-10: Synthesis of H-[5-7]-OMe (H-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe)

[1805]

[1806] Fmoc-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe (0.563 mol, 1.0 equiv) was dissolved in EtOAc / DMSO (9: 1; v: v) (5.2 L). DBU (0.281 mol, 0.5 equiv) was added to the solution. The reaction mixture was stirred at room temperature for 1.5 hours until the reaction was complete. The organic product layer was diluted with EtOAc and washed twice with H2O. The aqueous phase was washed twice with EtOAc. The organic phases were combined and evaporated at 40°C. The residue was co-distilled twice with EtOAc. The residue was stored at 4°C to 5°C overnight and used directly as the starting material for the following step (step 11, synthesis of Fmoc-[4-7]-OMe).

[1807] Example IV-11: Fmoc-[4-7]-OMe(Fmoc-Trp(7Me)-Lys(Ac)-Pen(Acm)-Tyr(2-Boc- Synthesis of ea)-OMe)

[1808]

[1809] To a solution of H-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe (0.512 mol, 1.0 equiv) in EtOAc / DMSO (8:2; v:v) (2.6 L) was added Fmoc-Trp(7Me)-OH (0.415 mol, 0.81 equiv) and TBTU (0.486 mol, 0.95 equiv), and the reaction mixture was stirred at room temperature for 2 minutes. DIPEA (1.024 mol, 2.00 equiv) was added and the reaction mixture was stirred at room temperature for 2 hours until the reaction was complete. The reaction mixture was diluted with EtOAc and washed twice with a 5% NaHCO3 aqueous solution. The aqueous phase was washed with EtOAc. The organic phase was evaporated at 40°C. The residue was azeotroped twice with EtOAc. The residue was diluted with EtOAc and slowly added to IPE / heptane (1:1; v:v) over 10 minutes. The suspension was filtered and washed three times with IPE.The solid was dried under high vacuum at 35°C overnight to give 487.67 g (76% yield over two steps, 95% HPLC purity) of the desired product as a white solid.

[1810] Example IV-12: Synthesis of Boc-[12-13]-NH2(Boc-3Pal-Sarc-NH2)

[1811]

[1812] Boc-3-Pal-OH (106.5 g, 0.40 mol, 1.0 eq) was dissolved in DMF (0.5 L) and cooled to -6 ° C. Pyridine (32 mL, 1.0 eq) and NMM (44 mL, 1.0 eq) were added, and the mixture was cooled to -25 ° C. Pivaloyl chloride (49 mL, 1.0 eq) was added, and the mixture was stirred at -10 ° C for 20 minutes. In a parallel reactor, H-Sar-NH2·HCl (49.8 g, 1.0 eq) was dissolved in DMF (250 mL) and water (50 mL), and the solution was cooled to 0 ° C. After adding NMM (44 mL), the resulting amine solution was added to the activated Boc-3-Pal-OH solution. The resulting suspension was stirred at room temperature for 14 hours until the reaction was complete. The suspension was cooled to 3°C and the precipitated product was filtered off, washed four times with 250 mL of cold water (4°C) and dried under vacuum at 35°C for 14 h to give the desired product (116 g, 88% yield, 99% HPLC purity) as a white solid.

[1813] Example IV-13: Synthesis of H-[12-13]-NH2.HCl (H-3Pal-Sarc-NH2) .

[1814]

[1815] Under good stirring, Boc-3-Pal-Sar-NH2 (115 g, 0.34 mol) was added to HCl (3.4 N, 1.2 L) in EtOAc. The reaction was complete after 1 hour. The suspension was filtered, the residue was washed three times with 0.5 L EtOAc, and dried under vacuum at 35°C for 16 hours to obtain the desired product (163 g, >100% yield, 99% HPLC purity) as a white solid.

[1816] Example IV-14: Synthesis of Cbz-Asn-3Pal-Sarc-NH2

[1817]

[1818] Preactivation of Z-Asn-OH

[1819] 87.5 g Z-Asn-OH (0.33 mol, 1.1 eq) and 41.6 g (1.2 eq) HOSu were dissolved in 440 mL DMF and the solution was cooled to 0°C. DIC (54 mL, 1.1 eq) was added over 5 minutes and the mixture was stirred at 0°C for 17 hours. The resulting suspension was clarified by filtration, and the filter cake was washed twice with 40 mL of DMF each time. The filtrate was used directly in the coupling reaction.

[1820] Coupling and workup

[1821] At 10 ° C, 140.6 g (49.6% peptide content; 0.30 mol; 1.0 equivalent) of H-3-Pal-Sar-NH2·HCl was added to the solution of Z-Asn-OSu and a total of 117 mL of triethylamine was added under cooling (maximum temperature 32 ° C) within 1 hour to adjust the pH to 7, resulting in a thick suspension. The suspension was stirred for another 30 minutes until the reaction was complete. 875 mL of ACN was added to the thick product suspension, which was stirred for 1 hour. The product was filtered off, washed 5 times with 1 L of ACN each time, and dried under vacuum at 35 ° C for 18 hours to give the desired product (113 g, 78% yield, 99.3% HPLC purity) as a white solid.

[1822] Example IV-15: Synthesis of H-[11-13]-NH2(H-Asn-3Pal-Sarc-NH2)

[1823]

[1824] Z-Asn-3-Pal-Sar-NH2 (111.4 g, 0.23 mol) was suspended in DMF (0.9 L). After adding 11 g of Pd / C catalyst, hydrogen was continuously bubbled into the mixture for 7 hours to finally dissolve the starting material. The mixture was kept at 4°C overnight, resulting in precipitation of the product. This suspension (1 L) was used in the next coupling step without filtering off the catalyst.

[1825] Example IV-16: Synthesis of Cbz-[10-13]-NH2(Cbz-Glu(tBu)-Asn-3Pal-Sarc-NH2)

[1826]

[1827] Preactivation of Z-Glu(OtBu)-OH

[1828] Z-Glu(OtBu)-OH (77.4 g, 0.23 mol, 1.0 eq) and HOSu (29.1 g, 1.1 eq) were dissolved in DMF (200 mL) and the solution was cooled to 0° C. DIC (37 mL, 1.04 eq) was added over 10 minutes. The reaction was heated to 25° C. over 10 hours and stirred for a further 8 hours.

[1829] Coupling and workup

[1830] Z-Glu (OtBu) -OSu was added as a suspension to a 1.0 L suspension of H-Asn-3-Pal-Sar-NH2 (1.0 eq) (H-[11-13] -NH2) in DMF from the previous step. The pH was adjusted to pH 8.5 by addition of Et3N (16 mL, 0.5 eq) and the mixture was stirred for 90 minutes.

[1831] The suspension was filtered. The filtrate was extracted continuously with 2L IPE / hexane 1:1, 2L IPE and 1L IPE. During the extraction process, the product began to precipitate. The lower phase was evaporated to a thick suspension (0.5L) and diluted with 1L THF to obtain a dilute suspension. The product was leached and washed with 1L DMF / THF 1:3, and washed twice with 1L THF at each time, and dried under vacuum at 35°C for 16 hours to obtain a crude product (109g, 71% productive rate, 98% HPLC purity).

[1832] Purification was performed by suspension in water: Z-Glu(OtBu)-Asn-3-Pal-Sar-NH2 (109 g) was suspended in water (550 mL) at 65° C. for 5 minutes and stirred at 25° C. for 30 minutes. The product was filtered off, washed three times with 0.5 L of water, and dried under vacuum at 35° C. for 20 hours to give the desired product (85 g, 55% overall yield, 99% HPLC purity).

[1833] Example IV-17: Synthesis of H-[10-13]-NH2(H-Glu(tBu)-Asn-3Pal-Sarc-NH2)

[1834]

[1835] Z-Glu(OtBu)-Asn-3-Pal-Sar-NH2 (105 g, 1.0 equivalent) was suspended in MeOH (1130 mL) and water (170 mL). The mixture was stirred at 40°C until the starting material was completely dissolved. Pd / C (10.5 g) was then added, and the reaction mixture was stirred at 40°C under 3.5 bar of hydrogen pressure for 2 hours. The reaction suspension was filtered, and the filter cake was washed with MeOH (2 x 60 mL). The filtrate was dried over Na2SO4 at 45°C and concentrated under reduced pressure. The residue was poured into IPE (4000 mL), stirred at room temperature for 15 minutes, the suspension was filtered, and the filter cake was washed with IPE (2 x 100 mL). The white solid was dried in a vacuum oven at 35°C for 18 hours to obtain 78.0 g (93% yield, 96% HPLC purity) of the desired product as a white solid.

[1836] Example IV-18: Synthesis of Fmoc-[8-9]-OH (Fmoc-2Nal-Gly(THP)-OH)

[1837]

[1838] Under an inert atmosphere, N,O-bis(trimethylsilyl)acetamide (30.1 g, 2.4 eq) was added to a suspension of H-THPGly-OH (10.8 g, 1.2 eq) in acetonitrile (120 mL). The reaction mixture was heated to 70°C and stirred at this temperature for 1 hour. PivCl (8.2 g, 1.1 eq) and NMM (6.9 g, 1.1 eq) were added to a solution of Fmoc-2-Nal-OH (27.0 g, 1 eq) in 2-methyltetrahydrofuran (200 mL) cooled to 0°C. The solution was warmed to 10°C. The H-THPGly-OH solution was added to the cold Fmoc-2-Nal-THPGly-OH suspension over 30 minutes, and the reaction mixture was stirred at room temperature overnight. Me-THF (200 mL) was added to the reaction mixture. The organic phase was extracted twice with NaHSO (about 5% equivalent) and washed once with NaCl (about 3% equivalent). The solution was concentrated at 45°C and azeotroped with Me-THF. The residue was diluted with Me-THF (90 mL) and slowly precipitated in heptane (900 mL). The white suspension was filtered and washed with heptane (100 mL). The solid was dried in a vacuum drying oven at 40°C. 35 g of Fmoc-2-Nal-THPGly-OH (100% yield, 97% HPLC purity) was obtained as a white solid.

[1839] Example IV-19: Fmoc-[8-13]-NH2(Fmoc-2Nal-Gly(THP)-Glu(tBu)-Asn-3Pal- Synthesis of Sarc-NH2)

[1840]

[1841] Fmoc-2-Nal-THPGly-OH (59.0 g, 1.0 equiv) and H-Glu(OtBu)-Asn-3-Pal-Sar-NH2 (67.2 g, 1.2 equiv) were suspended in MeTHF (1490 mL) and DMSO (310 mL), and the mixture was cooled to 0°C to 5°C. PyAOP (59.9 g, 1.1 equiv) was added in one portion, followed by DIPEA (36.4 mL, 2.0 equiv). The reaction mixture was then allowed to warm to room temperature and stirred for 16 hours. The reactant was then diluted with MeTHF (1500 mL) and extracted with 2% NaHCO3 (2 × 2000 mL) and brine (4% NaCl aqueous solution) (1 × 2000 mL). The organic phase was evaporated under reduced pressure at 45°C, and the remaining oil was co-distilled with MeTHF (2 × 1000 mL). The remaining thick suspension was diluted with MTBE (1250 mL) and stirred at 40° C. for 20 minutes and at room temperature for 30 minutes. The suspension was then filtered and the filter cake washed with MTBE (3×300 mL). The white solid was dried in a vacuum oven at 30° C. for 2 days to give 133 g (99% yield, 95% HPLC purity) of the desired product as a white solid.

[1842] Example IV-20: H-[4-7]-OMe(H-Trp(7Me)-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)- Synthesis of OMe

[1843]

[1844] To a solution of Fmoc-7Me-Trp-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe (450 g, 397 mmol, 1.0 eq) in EtOAc / DMSO (8:2, v:v) (4.5 L) was added DBU (29.63 mL, 198.5 mmol, 0.5 eq) at room temperature and the reaction mixture was stirred at room temperature. IPC-HPLC after 1 hour showed 0.01% Fmoc-7-Me-Trp-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe. 1.5 hours after the addition of DBU, the reaction mixture was diluted with EtOAc / Me-THF 1:1 (9.0 L). The organic solution was washed twice with NaHCO (5% in water) (4.5 L) and once with H O (4.5 L). The aqueous phases were combined and washed with EtOAc / Me-THF 1:1 (4.5 L). The organic phase was evaporated under reduced pressure at 40 ° C. The residue was co-evaporated with EtOAc (3×2 L). The residue was stored at 4 ° C to 5 ° C overnight. The residue was absorbed in EtOAc (1 L) to give a total volume of 3 L. The diluted mixture was added to IPE (30 L) at room temperature within 5 minutes. The suspension was stirred at room temperature for 10 minutes. The suspension was filtered and the filter cake was washed twice with IPE (1.5 L). The white solid was dried at 35 ° C under high vacuum overnight. The white solid (345.7 g) was redissolved in EtOAc (3.5 L) within 10 minutes. The solution was added to IPE (35 L) within 10 minutes. The white suspension was stirred at room temperature for 30 minutes. The white suspension was filtered and the filter cake was washed twice with IPE (1.5 L). The white solid was dried at 35 °C under high vacuum overnight to give H-Trp(7Me)-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe (336 g, 93%, assay (Q-NMR): 89%).

[1845] Example IV-21: Ac-[1-7]-OMe(Ac-Pen(Trt)-Asn-Thr(tBu)-Trp(7Me)-Lys(Ac)- Synthesis of Pen(Acm)-Tyr(2-Boc-ea)-OMe)

[1846]

[1847] A double-jacketed 10 L glass reactor was charged with Ac-Pen(Trt)-Asn-Thr(tBu)-OH (212.0 g, 273.692 mmol, 1.0 equiv), H-7Me-Trp-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe (275.4 g, 93.3 w / w%, 281.903 mmol, 1.0 equiv), Oxyma B (50.7 g, 273.692 mmol, 1.0 equiv), and acetonitrile (3.23 kg, 4.2 L). The mixture was stirred at 25° C. for 30 minutes (red - fine suspension). DIC (38.0 g, 301.061 mmol, 1.1 equiv) was added over 5 minutes, and the reaction mixture was stirred at 25° C. IPC-HPLC after 3 hours indicated the reaction was complete. A white to beige suspension was formed. The suspension was stirred at 25°C for an additional 21 hours, and the product was isolated by filtration through a 3-pore glass filter. The filter cake was washed with ACN (3 x 0.3 L). The wet product was resuspended in ACN (2.0 L, 1.55 kg), and the suspension was heated to 40°C over 30 minutes and stirred at this temperature for 1.5 hours. The suspension was cooled to 15°C over 1 hour and stirred at this temperature for 6 hours. The product was isolated by filtration through a 3-pore glass filter. The filter cake was washed with ACN (3 x 0.3 L mL) and dried under reduced pressure at 35°C to yield 364.0 g of an off-white to beige solid (HPLC purity: 97.0% (D-allo-Thr: 0.08%), ESI-MS: m / z = 1597.32 [M+H+], yield: 83.2%, peptide content (CAT): 91.7%, HPLC assay: 89.1%).

[1848] Example IV-22: Ac-[1-7]-OH-straight chain (Ac-Pen(Trt)-Asn-Thr(tBu)-Trp(7Me)-Lys Synthesis of (Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OH-straight chain

[1849]

[1850] Ac-[1-7]-OMe (150.0 g, 89.1% w / w, 83.637 mmol, 1.0 eq), THF (0.75 L, 0.657 kg) and water (0.525 L, 0.525 kg) were charged into a 1.5 L glass jacketed reactor with an overhead stirrer. The mixture was stirred at 25° C. until a solution was obtained and cooled to 0° C. over 30 minutes. A solution of LiOH x H 2 O (5.264 g, 125.455 mmol, 1.5 eq) in water (0.225 L, 0.225 kg) was added to the reaction mixture over 1 hour with stirring, maintaining the temperature between 0° C. and 2° C. 2 hours after the addition of the LiOH solution was complete, IPC-HPLC showed that the reaction was complete (product: 99.1%, D-Tyr: 0.9%, SM: not detected). The pH of the reaction mixture was adjusted to 4.9 with HCl (concentrated), and the mixture was heated to 25°C within 30 minutes. The reaction mixture was diluted with MeTHF (1.5 L) and the phases were separated. The solvent was evaporated from the organic layer under reduced pressure at 40°C. 300 mL of the residue was co-evaporated with EtOAc (3 × 1 L). After the second co-evaporation, the product began to precipitate. The suspension was absorbed in EtOAc (820 mL), stirred at 60°C for 30 minutes, cooled to 25°C within 4 hours, and stirred at this temperature ...

Claims

1. A method for preparing a monocyclic peptide or a salt thereof, comprising coupling a monocyclic peptide fragment with a linear peptide fragment, wherein the single-ring peptide fragment is a peptide containing 4 to 11 amino acid residues; wherein the single-ring peptide fragment comprises a ring containing 4 to 8 amino acid residues; wherein the linear peptide fragment is a peptide containing 4 to 10 amino acid residues; and wherein an amide bond is formed between the single-cyclic peptide fragment and the linear peptide fragment.

2. The method according to claim 1, wherein the coupling of the single-cyclic peptide fragment and the linear peptide fragment is performed in solution phase without the use of a solid support.

3. The method according to claim 1 or claim 2, wherein the single-cyclic peptide has a relative molecular weight (RMM) greater than 1000. 4 . The method according to claim 1 , wherein the single-cyclic peptide fragment is a peptide having a relative molecular weight (RMM) of 500 to 3500. 5 . The method according to claim 1 , wherein the linear fragment is a peptide having a relative molecular weight (RMM) of 500 to 3000. 6 . The method according to claim 1 , wherein the amide bond is formed between an amino acid residue at the C-terminus of the single-cyclic peptide fragment and an amino acid residue at the N-terminus of the linear peptide fragment.

7. The method according to any one of claims 1 to 5, wherein the amide bond is formed between an amino acid residue at the N-terminus of the single-cyclic peptide fragment and an amino acid residue at the C-terminus of the linear peptide fragment.

8. The method according to any one of claims 1 to 7, wherein the single-cyclic peptide fragment comprises a ring cyclized by a bond between the side chains of two amino acid residues.

9. The method according to any one of claims 1 to 8, wherein the single-cyclic peptide fragment comprises a ring cyclized via a disulfide bridge or a thioether bond between the side chains of two amino acid residues.

10. The method according to any one of claims 1 to 9, wherein the single-cyclic peptide fragment comprises a loop containing 6 amino acid residues.

11. The method according to any one of claims 1 to 10, wherein the single-cyclic peptide fragment is a peptide containing 7 amino acid residues.

12. The method according to any one of claims 1 to 9, wherein the single-cyclic peptide fragment is a peptide containing 7 amino acid residues, and wherein 6 of the amino acid residues form the ring.

13. The method according to any one of claims 1 to 12, wherein the linear peptide fragment is a peptide containing 5 or 6 amino acid residues. The method according to claim 13 , wherein the linear peptide fragment is a peptide containing 6 amino acid residues.

15. The method according to any one of claims 1 to 14, wherein the linear peptide fragment is an unbranched peptide.

16. The method according to any one of claims 1 to 15, wherein the single-cyclic peptide fragment comprises a loop to which is appended at least one peptide chain comprising at least one amino acid residue.

17. The method according to any one of claims 1 to 16, wherein the amide bond is formed using a coupling reagent selected from the group consisting of carbodiimide coupling reagents, carbodiimides in the presence of additives, ammonium coupling reagents, urea coupling reagents, phosphonium coupling reagents, halogenating reagents, acylazoles, acyl azides, acid halides, organophosphorus reagents, organosulfur reagents, triazine coupling reagents, pyridinium coupling reagents, mixed anhydride reagents and activated esters.

18. The method according to any one of claims 1 to 17, further comprising the step of cyclizing a second linear peptide fragment to form the single-cyclic peptide fragment, wherein the second linear peptide fragment is a peptide containing 4 to 11 amino acid residues.

19. The method of claim 18, wherein the step of cyclizing the second linear peptide fragment comprises forming a bond between the side chains of two amino acid residues.

20. The method of claim 19, wherein the step of cyclizing the second linear peptide fragment comprises forming a bond between the side chain of the amino acid residue at the N-terminus and the side chain of the amino acid residue adjacent to the amino acid residue at the C-terminus.

21. The method according to any one of claims 18 to 20, wherein the step of cyclizing the second linear peptide fragment comprises forming a disulfide bridge or a thioether bond between the side chains of two amino acid residues.

22. The method of claim 21, wherein the disulfide bridge is formed in the presence of an oxidizing agent.

23. The method of claim 21, wherein the thallium(III) trifluoroacetate or trans-[Pt(en)2Cl2] 2+ The disulfide bridge is formed in the presence of 24. The method of claim 1, wherein the single-cyclic peptide fragment is a peptide of formula (III-A), (III-B) or (III-C): R 1 -X1a-X2a-X3a-X4a-X5a-X6a-X7a-X8a-X9a-R 3 (III-A); R 1 -X1a-X2a-X3a-X4a-X5a-X6a-X7a-X8a-X9a-X10a-R 3 (III-B); R 1 -X1a-X2a-X3a-X4a-X5a-X6a-X7a-X8a-X9a-X10a-X11a-R 3 (III-C); wherein each of X1a, X2a and X3a is independently absent or an amino acid residue; Each of X4a, X5a, X6a, X7a, X8a, X9a, X10a and X11a is an amino acid residue; R 1 H or C 1-20 Alkanoyl; R 3 OH or OP 2 ; and P 2 is a carboxyl protecting group, and wherein the peptide of each of Formula (III-A), (III-B) or (III-C) is cyclized via a bond between two amino acid residues to form a ring containing 4 to 8 amino acid residues.

25. The method of claim 24, wherein the peptide of each of Formula (III-A), (III-B), or (III-C) is cyclized via a bond between X4a and X9a.

26. The method of claim 1, wherein the linear peptide fragment is a peptide of formula (IV-A), (IV-B) or (IV-C): R 2 -X10a-X11a-X12a-X13a-X14a-X15a-X16a-X17a-X18a-X19a-R 4 (IV-A); R 2 -X11a-X12a-X13a-X14a-X15a-X16a-X17a-X18a-X19a-R 4 (IV-B); R 2 -X12a-X13a-X14a-X15a-X16a-X17a-X18a-X19a-R 4 (IV-C); wherein each of X10a, X11a, X12a, X13a, X14a and X15a is an amino acid residue; Each of X16a, X17a, X18a and X19a is independently absent or an amino acid residue; R 2 is H; R 4 For NHP 1 OP 2 , NH2 or OH, P 1 is an amino protecting group; and P 2 A carboxyl protecting group.

27. The method of claim 1, wherein the single-cyclic peptide fragment is a peptide of formula (III-A): R 1 -X1a-X2a-X3a-X4a-X5a-X6a-X7a-X8a-X9a-R 3 (III-A); wherein each of X1a, X2a and X3a is independently absent or an amino acid residue; Each of X4a, X5a, X6a, X7a, X8a and X9a is an amino acid residue; R 1 H or C 1-20 Alkanoyl; R 3 OH or OP 2 ; and wherein the peptide of formula (III-A) is cyclized via a bond between two amino acid residues to form a ring containing 4 to 8 amino acid residues; and wherein the linear peptide fragment has formula (IV-A): R 2 -X10a-X11a-X12a-X13a-X14a-X15a-X16a-X17a-X18a-X19a-R 4 (IV-A); wherein each of X10a, X11a, X12a, X13a, X14a and X15a is an amino acid residue; Each of X16a, X17a, X18a and X19a is independently absent or an amino acid residue; R 2 is H; R 4 For NHP 1 OP 2 , NH2 or OH; P 1 is an amino protecting group; and Each P 2 are independently carboxyl protecting groups; And wherein the amide bond is formed between X9a of formula (III-A) and X10a of formula (IV-A).

28. The method of claim 27, wherein the peptide of formula (III-A) is cyclized via the bond between X4a and X9a.

29. The method of claim 1, wherein the single-cyclic peptide fragment is a peptide of formula (III-B): R 1 -X1a-X2a-X3a-X4a-X5a-X6a-X7a-X8a-X9a-X10a-R 3 (III-B); wherein each of X1a, X2a and X3a is independently absent or an amino acid residue; Each of X4a, X5a, X6a, X7a, X8a, X9a and X10a is an amino acid residue; R 1 H or C 1-20 Alkanoyl; R 3 OH or OP 2 ; and wherein the peptide of each of formula (III-B) is cyclized via a bond between two amino acid residues to form a ring containing 4 to 8 amino acid residues; and wherein the linear peptide fragment has formula (IV-B): R 2 -X11a-X12a-X13a-X14a-X15a-X16a-X17a-X18a-X19a-R 4 (IV-B); wherein each of X11a, X12a, X13a, X14a and X15a is an amino acid residue; Each of X16a, X17a, X18a and X19a is independently absent or an amino acid residue; R 2 is H; R 4 For NHP 1 OP 2 , NH2 or OH; P 1 is an amino protecting group; and Each P 2 are independently carboxyl protecting groups; And wherein the amide bond is formed between X10a of formula (III-B) and X11a of formula (IV-B).

30. The method of claim 29, wherein the peptide of formula (III-B) is cyclized via the bond between X4a and X9a.

31. The method of claim 1, wherein the single-cyclic peptide fragment is a peptide of formula (III-C): R 1 -X1a-X2a-X3a-X4a-X5a-X6a-X7a-X8a-X9a-X10a-X11a-R 3 (III-C); wherein each of X1a, X2a and X3a is independently absent or an amino acid residue; Each of X4a, X5a, X6a, X7a, X8a, X9a, X10a and X11a is an amino acid residue; R 1 H or C 1-20 Alkanoyl; R 3 OH or OP 2 ; and wherein the peptide of each of formula (III-C) is cyclized via a bond between two amino acid residues to form a ring containing 4 to 8 amino acid residues; and wherein the linear peptide fragment has the formula (IV-C): R 2 -X12a-X13a-X14a-X15a-X16a-X17a-X18a-X19a-R 4 (IV-C); wherein each of X12a, X13a, X14a and X15a is an amino acid residue; wherein each of X16a, X17a, X18a and X19a is independently absent or an amino acid residue; R 2 is H; and R 4 For NHP 1 OP 2 , NH2 or OH; P 1 is an amino protecting group; and Each P 2 are independently carboxyl protecting groups; And wherein the amide bond is formed between X11a of formula (III-C) and X12a of formula (IV-C).

32. The method of claim 31, wherein the peptide of formula (III-C) is cyclized via the bond between X4a and X9a.

33. The method of any one of claims 24 to 32, wherein the amide bond is formed using a coupling reagent selected from the group consisting of carbodiimide coupling reagents, carbodiimides in the presence of additives, ammonium coupling reagents, urea coupling reagents, phosphonium coupling reagents, chlorination reagents, acylazoles, acyl azides, acid halides, organophosphorus reagents, organosulfur reagents, triazine coupling reagents, pyridinium coupling reagents, and mixed anhydride reagents.

34. The method of claim 33, wherein the amide bond is formed using a carbodiimide coupling reagent in the presence of an additive selected from the group consisting of ethyl cyanohydroxyiminoacetate (Oxyma Pure), 1-hydroxy-7-azabenzotriazole (HOAt), hydroxybenzotriazole (HOBt), 2-hydroxypyridine-N-oxide (HOPO), N-hydroxysuccinimide (HOSu), 5-(hydroxyimino)-1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione (Oxyma B), hexafluoroisopropanol (HFIP), and 4-nitrophenyl alcohol.

35. The method according to claim 33 or 34, wherein the carbodiimide coupling reagent is selected from N,N'-diisopropylcarbodiimide (DIC), N,N'-dicyclohexylcarbodiimide (DCC), 1,1'-carbonyldiimidazole (CDI), N-ethyl-N'-dimethylaminopropylcarbodiimide (EDC), N-ethyl-N'(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCI), N-cyclohexyl-N'-dimethylaminopropylcarbodiimide hydrochloride (EDCI), '-Isopropylcarbodiimide (CIC), N-tert-butyl-N'-methylcarbodiimide (BMC), N-tert-butyl-N'-ethylcarbodiimide (BEC), N,N'-dicyclopentylcarbodiimide (CPC), bis(4-(2,2-dimethyl-1,3-dioxolane))methylcarbodiimide (BDDC), N-ethyl-N'-phenylcarbodiimide (PEC), N-phenyl-N'-isopropylcarbodiimide (PIC).

36. The method of claim 33, wherein the ammonium coupling reagent is O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate (TBTU) or 1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxide hexafluorophosphate (HATU), O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HBTU), 3-(diethylphosphoryloxy)-1,2,3-benzotriazin-4(3H)-one (DEPBT), O-(6-chlorobenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HCTU) and O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate (TATU).

37. The method of claim 33, wherein the urea coupling reagent is O-(5-norbornene-2,3-dicarboximide)-N,N,N',N'-tetramethyluronium tetrafluoroborate (TNTU), O-(N-succinimidyl)-1,1,3,3-tetramethyluronium tetrafluoroborate (TSTU), O-(3,4-dihydro-4-oxo-1,2,3-benzotriazol-3-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate (TDBTU), O-(1,2-dihydro-2-oxo-1-pyridyl-N,N,N',N'-tetramethyluronium tetrafluoroborate (TPTU), or O-((ethoxycarbonyl)cyano-methyleneamino)-N,N,N',N'-tetramethyluronium tetrafluoroborate (TOTU).

38. The method of claim 33, wherein the phosphonium coupling reagent is (7-azabenzotriazol-1-yloxy)tripyrrolidinylphosphonium hexafluorophosphate (PyAOP), benzotriazol-1-yloxy-tris(dimethylamino)phosphonium hexafluorophosphate (BOP), (benzotriazol-1-yloxy)tripyrrolidinylphosphonium hexafluorophosphate (PyBOP), tripyrrolidinylphosphonium bromide hexafluorophosphate (PyBrOP), bis(2-oxo-3-oxazolidinyl)phosphinyl chloride (BOP-Cl), 1-cyano-2-ethoxy-2-oxoethyleneaminooxy-tripyrrolidinyl-phosphonium hexafluorophosphate (PyOxim), and 6-chloro-benzotriazol-1-yloxy-tripyrrolidinylphosphonium hexafluorophosphate (PyClock).

39. The method of any one of claims 33 to 38, wherein the coupling is performed in the presence of a tertiary amine base.

40. The method of claim 39, wherein the tertiary amine base is selected from the group consisting of N-methylmorpholine (NMM), diisopropylethylamine (DIPEA), 1,4-diazabicyclo[2.2.2]octane (DABCO), diethylamine (DEA), triethylamine (TEA), and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU).

41. The method of any one of claims 33 to 40, wherein the coupling is performed in the presence of a solvent selected from the group consisting of acetonitrile (MeCN), methyltetrahydrofuran (MeTHF), dimethyl sulfoxide (DMSO), ethyl acetate (EtOAc), dimethylformamide (DMF), tetrahydrofuran (THF), methanol, ethanol, water, dimethylacetamide (DMA), N-methyl-2-pyrrolidine (NMP), and 2-propanol.

42. The method according to any one of claims 27, 28, and 33 to 41, further comprising the step of preparing the single-cyclic peptide fragment, comprising cyclizing a second linear peptide fragment to form a disulfide bond or a thioether bond between X4a and X9a, wherein the second linear peptide fragment is a peptide of formula (III-A'): R 1 -X1a-X2a-X3a-X4a-X5a-X6a-X7a-X8a-X9a-R 5 (III-A'); Among them, X1a to X9a and R 1 As defined in claim 27, and R 5 OH or OP 2 .

43. The method according to any one of claims 29, 30, and 33 to 41, further comprising the step of preparing the single-cyclic peptide fragment, comprising cyclizing a second linear peptide fragment to form a disulfide bond or a thioether bond between X4a and X9a, wherein the second linear peptide fragment is a peptide of formula (III-B'): R 1 -X1a-X2a-X3a-X4a-X5a-X6a-X7a-X8a-X9a-X10a-R 5 (III-B'); Among them, X1a to X10a and R 1 As defined in claim 29, and R 5 OH or OP 2 .

44. The method according to any one of claims 31, 32, and 33 to 41, further comprising the step of preparing the single-cyclic peptide fragment, comprising cyclizing a second linear peptide fragment to form a disulfide bond or a thioether bond between X4a and X9a, wherein the second linear peptide fragment is a peptide of formula (III-C'): R 1 -X1a-X2a-X3a-X4a-X5a-X6a-X7a-X8a-X9a-X10a-X11a-R 5 (III-C'); Among them, X1a to X10a, R 1 and R 3 As defined in claim 31, and R 5 OH or OP 2 .

45. The method of any one of claims 24 to 44, wherein each of the amino acid residues is independently selected from naturally occurring and non-naturally occurring amino acids, and amino acid analogs and amino acid mimetics that function in a manner similar to the naturally occurring amino acids.

46. The method of any one of claims 1 to 45, wherein each of the amino acid residues is independently selected from the group consisting of Gly, Ala, β-Ala, Leu, Met, Phe, Phe substituted with halo, alkyl, haloalkyl, hydroxy, alkoxy, cyano, cycloalkyl, carboxyl, carboxamido, 2-aminoethoxy (2-ea) or 2-acetamidoethoxy, Trp, Trp substituted with cyano, halo, alkyl, substituted aryl, unsubstituted aryl, haloalkyl, hydroxy or alkoxy, Lys, Gl n, β-homoGln, Pro, Val, Ile, Cys, (D) Cys, α-MeCys, (D) Pen, Pen or Pen (sulfoxide), Cit, Tyr, His, (D) His, Arg, Asn, Glu, S er, α-MeSer, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, α-MeThr, Lys(Ac), α-MeLys(Ac), α-MeArg, α-MePhe, α-MeTyr Dab(Ac), Dap(Ac), homo-Lys(Ac), Asp, Thr, Sarc, Aib, Dab, Dap, γ-Glu, Gaba, β-Pro, Abu, 1Nal, 2Nal, Lys(b-Ala), Lys(Gly), Lys(benzyl, Ac), Lys(butyl, Ac), Lys(isobutyl, Ac), Lys(propyl, Ac), Lys(PEG2PEG2gEC18OH), Phe(2-Me), Phe(3-Me), Phe(4-Me), Phe(3,4-dimethoxy), 2Quin, 3Quin, 4-amino-4-carboxytetrahydropyran (Gly(THP)), Acvc, cyclohexylAla, 2Pal, 3Pal, 4Pal or 5Pyal.

47. The method according to any one of claims 24 to 46, wherein R 1 Selected from -C(O)CH3.

48. The method according to any one of claims 26 to 47, wherein P 1 is an amino protecting group selected from the group consisting of benzyl (Bn), trityl (Trt), 4-methyltrityl (Mtt), β-methoxyethoxytrityl (MEM), 2-nitrophenylsulfonyl (Nps), 2-(4-nitrophenyl)sulfonylethoxycarbonyl (Nsc), benzothiazole-2-sulfonyl (Bts), dithiasuccinyl (Dts), nitrobenzenesulfonyl (Ns), 2-(2-nitrophenyl)propoxycarbonyl (NPPOC), 2-(3,4-methylenedioxy-6-nitrophenyl)propoxycarbonyl (MNPPOC), methylsulfonylethoxycarbonyl (Msc), 9-fluorenylmethyloxycarbonyl (Fmoc), 2,7-di-tert-butyl-Fmoc (Fmoc*), 2-fluoro-Fmoc (Fmoc(2F)), 2-monoisooctyl-Fmoc (mio-Fmoc), benzyloxycarbonyl (Cbz), 2,2,2-tris(2,3-dimethylamino)-1,2-dimethylamino ... chloroethoxycarbonyl (Troc), 2-(trimethylsilyl)ethoxycarbonyl (Teoc), 2-(4-trifluoromethylphenylsulfonyl)ethoxycarbonyl (Tsc), tert-butoxycarbonyl (Boc), 1-adamantyloxycarbonyl (Adoc), 2-adamantyloxycarbonyl (2-Adoc), 2,4-dimethylpentan-3-yloxycarbonyl (Doc), cyclohexyloxycarbonyl (Hoc), 1,1-dimethyl-2,2,2-trichloroethoxycarbonyl (TcBOC), formyl, acetyl (Ac), trifluoroacetyl (TFA), p-toluenesulfonyl (Ts), vinyl, 2-chloroethyl, 2-phenylsulfonylethyl, allyl, 2-nitrobenzyl, 4-nitrobenzyl, diphenyl-4-pyridylmethyl, N',N'-dimethylhydrazine, methoxymethyl, tert-butoxymethyl (Bum), benzyloxymethyl (BOM), 2-tetrahydropyranyl (THP), tris(C 1-4 alkyl) silyl (e.g., tri(isopropyl)silyl), 1,1-diethoxymethyl, α,α-dimethyl-3,5-dimethoxybenzyloxycarbonyl (Ddz), 2-(p-biphenyl)-2-propoxycarbonyl (Bpoc), 1,1-dioxonaphtho[1,2-b]thiophene-2-methyloxycarbonyl (α-Nsmoc), 3,3-dioxonaphtho[2,1-b]thiophene-2-methyloxycarbonyl (β-Nsmoc), 1-(4,4-dimethyl-2,6-dioxocyclohexan-1-ylidene)ethyl (Dde), 1-(4,4-dimethyl-2,6-dioxocyclohexan-1-ylidene)ethyl) [0014] In some embodiments, the present invention may include phenyldithioethoxycarbonyl (ivDde), 2-(phenyl(methyl)sulfonium)ethoxycarbonyl (Pms), N-ethylsulfonylethoxycarbonyl (Esc), 2-(4-sulfophenylsulfonyl)ethoxycarbonyl (Sps), allyloxycarbonyl (Alloc), propargyloxycarbonyl (Poc), 9-(4-bromophenyl)-9-fluorenyl (BrPhF), azidomethoxycarbonyl (Azoc), N-tetrachlorophthaloyl (TCP), phenyldithioethoxycarbonyl (Phdec), 2-pyridyldithioethoxycarbonyl (Pydec), or N-pivaloyloxymethyl (POM).

49. The method according to any one of claims 26 to 48, wherein P 2 is a carboxyl protecting group selected from the group consisting of tert-butyl (tBu), methyl, ethyl, propyl, hexyl, p-methoxybenzyloxycarbonyl (Moz), allyl, 1,1-dimethylallyl (Dma), phenylacyl (Pac), p-nitrobenzyl (p-NB), trityl (Tr), 2-chlorotrityl (2-Cl-Trt), 2,4-dimethoxybenzyl (Dmb), 9-fluorenylmethyl (Fm), phenyl, cyclohexyl, benzyl (Bn), 3,4-ethylenedioxy-2-thienyl (EDOT n ), 4-(N-(1-(4,4-dimethyl-2,6-dioxocyclohexylidene)-3-methylbutyl)amino)benzyl (Dmab), trimethylsilylethyl (TMSE), 2-(trimethylsilyl)isopropyl (Tmsi), 2,2,2-trichloroethyl (Tce), carbamoylmethyl (Cam), 4,5-dimethoxy-2-nitrobenzyloxycarbonyl (Dmnb), pentaamminecobalt(III), β-menthyl (Men), β-3-menthylpent-3-yl (Mpe), or 2-phenylisopropyl (2-Ph(iPr)).

50. The method according to any one of claims 24 to 49, wherein Each of X1a, X2a, X3a, X18a and X19a is independently absent or any amino acid residue; X4a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide); X5a is Cit, Glu, Gly, substituted Gly, Leu, Ile, β-Ala, Ala, Lys, Asn, Pro, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, Lys(Ac), α-MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), Gln, Asp or Cys; X6a is Thr, 2-aminoisobutyric acid, Asp, Dab, Gly, Pro, Ser, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, α-MeThr, α-MeSer, or Val; X7a is unsubstituted Trp, or Trp substituted with cyano, halo, alkyl, substituted or unsubstituted aryl, haloalkyl, hydroxyl or alkoxy; X8a is Gln, α-Me-Lys, α-MeLeu, α-MeLys(Ac), β-homoGln, Cit, Glu, Phe, Asn, Thr, Val, 2-aminoisobutyric acid, α-MeGln, α-MeAsn, Lys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), 1Nal, 2Nal or Trp; X9a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide); each X10a is unsubstituted Phe, or Phe substituted with halo, alkyl, haloalkyl, hydroxy, alkoxy, carboxyl, carboxamido, 2-aminoethoxy, or 2-acetylaminoethoxy; each X11a is 2Nal, unsubstituted Trp, or Trp substituted with cyano, halo, alkyl, haloalkyl, hydroxy, alkoxy, Phe(2-Me), Phe(3-Me), Phe(4-Me), Phe(3,4-dimethoxy), or 1Nal; each X12a is 4-amino-4-carboxy-tetrahydropyran (Gly(THP)), α-MeLys, α-MeLeu, α-MeArg, α-MePhe, α-MeLeu, α-MeLys, α-MeAsn, α-MeTyr, Ala, cyclohexylAla, Lys, or 2-aminoisobutyric acid; X13a is 2-aminoisobutyric acid, Glu, Cit, Gln, Lys(Ac), α-MeArg, α-MeGlu, α-MeLeu, α-MeLys, α-Me-Asn, α-MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), or Lys; or X13a is Lys, pegylated Lys, b-homoGlu, or Lys(Y2-Ac), wherein Y2 is an amino acid residue; X14a is Asn, 2Nal, 2-aminoisobutyric acid, Arg, Cit, Asp, Phe, Gly, Lys, Leu, Ala, (D)Ala, β-Ala, His, Thr, n-Leu, Gln , Ser, (D)Ser, Tic, Trp, α-MeGln, α-MeAsn, α-MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac) or Lys(Ac); X15a is Ala, β-Ala, Arg, Asn, Asp, Cit, Cys, Glu, Gln, Gly, substituted or unsubstituted His, (D)His, Ile, Lue, (D)Lue, Lys, (D)Lys, Met, 2Pal, 3Pal or 4Pal, Phe, Pro, 5-Pyal, 2Quin, 3Quin, Ser, Thr, Trp, Tyr, Val, or Leu; X16a is absent or is Sarc, aMeLeu, (D)NMeTyr, His, (D)Thr, bAla, Pro, or (D)Pro; X17a is absent or is Lys(PEG2PEG2gEC18OH); and wherein the single-cyclic peptide fragment is cyclized via a Pen-Pen disulfide bond between X4a and X9a; or the single-cyclic peptide fragment is cyclized via an Abu-Cys or Abu-Pen thioether bond between X4a and X9a.

51. The method of claim 50, wherein the monocyclic peptide is a compound of Formula (Ia), (Ib), (Ic), (Id), or (Ie): R 1 -X4a-X5a-X6a-[Trp]-X8a-X9a-[Phe]-[2Nal]-X12a-X13a-X14a-X15a-X16a-R 4 (Ia)、 R 1 -X4a-X5a-X6a-[Trp]-X8a-X9a-[Phe]-X11a-X12a-X13a-X14a-[Pal]-X16a-R 4 (Ib)、 R 1 -X4a-X5a-X6a-X7a-X8a-X9a-[Phe]-[2Nal]-X12a-X13a-X14a-[Pal]-X16a-R 4 (Ic)、 R 1 -X4a-X5a-X6a-[Trp]-X8a-X9a-X10-[2Nal]-X12a-X13a-X14a-[Pal]-X16a-R 4 (Id); or R 1 -X4a-X5a-X6a-[Trp]-X8a-X9a-[Phe]-[2Nal]-X12a-X13a-X14a-[Pal]-X16a-R 4 (Ie) wherein Trp is unsubstituted Trp, or Trp substituted by cyano, halo, alkyl, haloalkyl, alkoxy, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl; wherein Phe is unsubstituted Phe, or Phe substituted with halo, alkyl, haloalkyl, hydroxy, alkoxy, cyano, cycloalkyl, carboxyl, carboxamido, 2-aminoethoxy, or 2-acetylaminoethoxy; wherein 2Nal is unsubstituted 2Nal; Wherein Pal is 2Pal, 3Pal or 4Pal.

52. A method according to any one of claims 1 to 28, 33 to 42, 45 to 51 for preparing a compound which is: Ac-Asp-Arg-Abu-Gln-Thr-Trp-Gln-Cys-Tyr(2ea)-2Nal-Gly(THP)-Glu-Asn-Asn-NH2; wherein the single-ring peptide fragment is Ac-Asp-Arg-Abu-Gln-Thr-Trp-Gln-Cys-OH, and the linear peptide fragment is H-Tyr(2ea)-2Nal-Gly(THP)-Glu-Asn-Asn-NH2; wherein the compound and the single-ring peptide fragment are cyclized between the Abu and Cys amino acid residues.

53. A method according to any one of claims 1 to 26, 29 to 30, 33 to 41, and 45 to 51, wherein the method is used to prepare a compound, wherein the compound is: Ac-Pen-Asn-Thr-W(7-Me)-Lys(Ac)-Pen-Tyr(2ea)-2Nal-αMeLys-Lys(Ac)-Asn-DLeu-NH2; wherein the single-ring peptide fragment is Ac-Pen-Asn-Thr-W(7-Me)-Lys(Ac)-Pen-Tyr(2ea)-OH, and the linear peptide fragment is H-2Nal-αMeLys-Lys(Ac)-Asn-DLeu-NH2; wherein the compound and the single-ring peptide fragment are cyclized between the Pen and Pen amino acid residues.

54. The method of any one of claims 50 to 53, wherein the amino, carboxyl, hydroxyl and thiol groups of each of X1a to X19a are independently protected with a protecting group.

55. The method of claim 1, wherein the single-cyclic peptide fragment is a compound of formula (III): And the linear peptide fragment is a compound of formula (IV): R 2 -X11a-X12a-X13a-X14a-X15a-X16a-R 4 (IV) and wherein an amide bond is formed between X10a and X11a to form a compound of formula (II): in R 1 H or C 1-20 Alkanoyl; R 2 is H; R 3 OH or OP 2 ; R 4 For NHP 1 or NH2; P 1 is an amino protecting group; P 2 is a carboxyl protecting group; X3a does not exist or is any amino acid residue; X4a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide); X5a is Cit, Glu, Gly, substituted Gly, Leu, Ile, β-Ala, Ala, Lys, Asn, Pro, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, Lys(Ac), α-MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), Gln, Asp or Cys; X6a is Thr, 2-aminoisobutyric acid, Asp, Dab, Gly, Pro, Ser, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, α-MeThr, α-MeSer, or Val; X7a is unsubstituted Trp, or Trp substituted with cyano, halo, alkyl, substituted or unsubstituted aryl, haloalkyl, hydroxyl or alkoxy; X8a is Gln, α-Me-Lys, α-MeLeu, α-MeLys(Ac), β-homoGln, Cit, Glu, Phe, Asn, Thr, Val, 2-aminoisobutyric acid, α-MeGln, α-MeAsn, Lys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), 1Nal, 2-Nal or Trp; X9a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide); X10a is unsubstituted Phe, or Phe substituted with halo, alkyl, haloalkyl, hydroxy, alkoxy, carboxyl, carboxamido, 2-aminoethoxy, or 2-acetylaminoethoxy; X11a is 2Nal, unsubstituted Trp, or Trp substituted with cyano, halo, alkyl, haloalkyl, hydroxy, alkoxy, Phe(2-Me), Phe(3-Me), Phe(4-Me), Phe(3,4-dimethoxy), or 1Nal; X12a is 4-amino-4-carboxytetrahydropyran (Gly(THP)), α-MeLys, α-MeLeu, α-MeArg, α-MePhe, α-MeLeu, α-MeLys, α-MeAsn, α-MeTyr, Ala, cyclohexylAla, Lys, or 2-aminoisobutyric acid; X13a is 2-aminoisobutyric acid, Glu, Cit, Gln, Lys(Ac), α-MeArg, α-MeGlu, α-MeLeu, α-MeLys, α-Me-Asn, α-MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), or Lys; or X13a is Lys, pegylated Lys, b-homoGlu, or Lys(Y2-Ac), wherein Y2 is an amino acid residue; X14a is Asn, 2Nal, 2-aminoisobutyric acid, Arg, Cit, Asp, Phe, Gly, Lys, Leu, Ala, (D)Ala, β-Ala, His, Thr, n-Leu, Gln , Ser, (D)Ser, Tic, Trp, α-MeGln, α-MeAsn, α-MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac) or Lys(Ac); X15a is Ala, β-Ala, Arg, Asn, Asp, Cit, Cys, Glu, Gln, Gly, substituted or unsubstituted His, (D)His, Ile, Lue, (D)Lue, Lys, (D)Lys, Met, 2Pal, 3Pal or 4Pal, Phe, Pro, 5-Pyal, 2Quin, 3Quin, Ser, Thr, Trp, Tyr, Val, or Leu; X16a is absent or is Sarc, aMeLeu, (D)NMeTyr, His, (D)Thr, bAla, Pro, or (D)Pro; And the compound is cyclized via a Pen-Pen disulfide bond between X4a and X9a; or the compound is cyclized via an Abu-Cys or Abu-Pen thioether bond between X4a and X9a.

56. The method of claim 55, wherein the amino, carboxyl, hydroxyl and thiol groups of the amino acid side chain of each of X3a to X19a are independently protected with a protecting group.

57. The method of claim 56, wherein the protecting group for each amino group on the amino acid side chain is independently selected from Fmoc, Cbz, and Boc.

58. The method of claim 56 or 57, wherein the protecting group for each carboxyl group on the amino acid side chain is independently selected from methyl, tert-butyl, trityl (Tr), 2,4-dimethoxybenzyl (Dmb), 9-fluorenylmethyl (Fm), benzyl (Bn).

59. The method of claim 56 to 58, wherein the protecting group for each hydroxyl group on the amino acid side chain is independently selected from C 1-6 alkyl.

60. The method of claims 56 to 59, wherein the thiol protecting group is independently selected from trityl (Tr) or acetamidomethyl (Acm).

61. The method of claims 55 to 60, wherein P 1 is Fmoc, Cbz, Ac, Bz or Boc.

62. The method according to any one of claims 55 to 61, wherein R 1 For -Ac.

63. The method according to any one of claims 55 to 62, wherein R 4 NH2 or NHP 1 .

64. The method of any one of claims 55 to 63, wherein the amide bond is formed using a carbodiimide coupling reagent, optionally in the presence of an additive.

65. The method of claim 64, wherein the amide bond is formed in the presence of N,N'-diisopropylcarbodiimide (DIC) and 5-(hydroxyimino)-1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione (Oxyma B).

66. The method of any one of claims 55 to 65, further comprising deprotecting the compound of formula (II) to form a compound of formula (I): where R 1 H or C 1-20 Alkanoyl; R 4 is NH2; X3 does not exist or is any amino acid residue; X4 is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide); X5 is Cit, Glu, Gly, substituted Gly, Leu, Ile, β-Ala, Ala, Lys, Asn, Pro, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, Lys(Ac), α-MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), Gln, Asp or Cys; X6 is Thr, 2-aminoisobutyric acid, Asp, Dab, Gly, Pro, Ser, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, α-MeThr, α-MeSer, or Val; X7 is unsubstituted Trp, or Trp substituted by cyano, halo, alkyl, substituted or unsubstituted aryl, haloalkyl, hydroxyl or alkoxy; X8 is Gln, α-Me-Lys, α-MeLeu, α-MeLys(Ac), β-homoGln, Cit, Glu, Phe, Asn, Thr, Val, 2-aminoisobutyric acid, α-MeGln, α-MeAsn, Lys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), 1Nal, 2-Nal or Trp; X9 is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide); X10 is unsubstituted Phe, or Phe substituted with halo, alkyl, haloalkyl, hydroxy, alkoxy, carboxyl, carboxamido, 2-aminoethoxy, or 2-acetylaminoethoxy; X11 is 2Nal, unsubstituted Trp, or Trp substituted with cyano, halo, alkyl, haloalkyl, hydroxy, alkoxy, Phe(2-Me), Phe(3-Me), Phe(4-Me), Phe(3,4-dimethoxy), or 1Nal; X12 is 4-amino-4-carboxytetrahydropyran (Gly(THP)), α-MeLys, α-MeLeu, α-MeArg, α-MePhe, α-MeLeu, α-MeLys, α-MeAsn, α-MeTyr, Ala, cyclohexylAla, Lys, or 2-aminoisobutyric acid; X13 is 2-aminoisobutyric acid, Glu, Cit, Gln, Lys(Ac), α-MeArg, α-MeGlu, α-MeLeu, α-MeLys, α-Me-Asn, α-MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), or Lys; or X13 is Lys, pegylated Lys, b-homoGlu, or Lys(Y2-Ac), wherein Y2 is an amino acid residue; X14 is Asn, 2Nal, 2-aminoisobutyric acid, Arg, Cit, Asp, Phe, Gly, Lys, Leu, Ala, (D)Ala, β-Ala, His, Thr, n-Leu, Gln, Ser, (D)Ser, Tic, Trp, α-MeGln, α-MeAsn, α-MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac) or Lys(Ac); X15 is Ala, β-Ala, Arg, Asn, Asp, Cit, Cys, Glu, Gln, Gly, substituted or unsubstituted His, (D)His, Ile, Lue, (D)Lue, Lys, (D)Lys, Met, 2Pal, 3Pal or 4Pal, Phe, Pro, 5-Pyal, 2Quin, 3Quin, Ser, Thr, Trp, Tyr, Val, Leu; X16 is absent or is Sarc, aMeLeu, (D)NMeTyr, His, (D)Thr, bAla, Pro, or (D)Pro; And the compound is cyclized via a Pen-Pen disulfide bond between X4 and X9; or the compound is cyclized via an Abu-Cys or Abu-Pen thioether bond between X4 and X9.

67. The method of claim 66, wherein the deprotection is performed using an acid.

68. The process of claim 67, wherein the deprotection is carried out in the presence of HCl in acetic acid.

69. The method of any one of claims 55 to 68, wherein X4a is (D)Pen, Pen, or Pen(sulfoxide); and X9a is (D)Pen, Pen, or Pen(sulfoxide).

70. The method according to claim 69, further comprising the step of preparing the compound of formula (III), said step comprising cyclizing the compound of formula (III') R 1 -X3a-X4a-X5a-X6a-X7a-X8a-X9a-X10a-R 5 (III') To form a Pen-Pen disulfide bond between X4a and X9a; wherein R 1 H or C 1-20 Alkanoyl; R 5 OH or OP 2 ; and P 2 A carboxyl protecting group.

71. The method of claim 70, wherein the thiol groups on X4a and X9a are deprotected before or during the cyclization of the compound of formula (III').

72. The method of claim 70 or 71, wherein the Pen-Pen disulfide bond is formed in the presence of an oxidizing agent.

73. The method of claim 70 or 71, wherein the Pen-Pen disulfide bond is formed in the presence of diiodine.

74. The method of any one of claims 70 to 73, wherein P 2 It is CH3 or C(CH3)3.

75. The method according to any one of claims 70 to 74, wherein R 1 For -Ac.

76. The method of claims 70 to 75, wherein R 5 For OH.

77. The process according to claims 55 to 76, wherein the step of preparing the compound of formula (III) comprises reacting a compound of formula (V) R 1 -X3a-X4a-X5a-X6a-R 3 (V) and a compound of formula (VI) R 2 -X7a-X8a-X9a-X10a-R 5 (VI) reacting to form an amide bond between X6a and X7a; in R 1 H or C 1-20 Alkanoyl; R 2 is H; R 3 OH or OP 2 ; R 5 OH or OP 2 ; and each P 2 is independently a carboxyl protecting group.

78. The method of claim 77, wherein the amide bond is formed using a carbodiimide coupling reagent, optionally in the presence of an additive.

79. The method of claim 78, wherein the amide bond is formed in the presence of N,N'-diisopropylcarbodiimide (DIC) and ethyl cyanohydroxyiminoacetate (Oxyma Pure).

80. The method of any one of claims 77 to 79, wherein R 1 It is C(O)CH3.

81. The method of any one of claims 77 to 80, wherein R 5 For OP 2 .

82. The method of any one of claims 77 to 81, wherein P 2 C 1-6 alkyl.

83. The method of claim 82, wherein P 2 For CH3.

84. The method of any one of claims 77 to 83, wherein the step of preparing a compound of formula (III) further comprises reacting a compound of formula (V'): R 7 -X3a-X4a-X5a-X6a-R 5 (V') Converted to a compound of formula (V): R 1 -X3a-X4a-X5a-X6a-R 3 (V) in R 1 H or C 1-20 Alkanoyl; R 3 OH or OP 2 ; R 5 OH or OP 2 ;and R 7 H or P 1 ; Among them, P 1 is an amino protecting group, and each P 2 is independently a carboxyl protecting group.

85. The method of claim 84, wherein R 7 It is Fmoc.

86. The method of claim 84 or 85, wherein R 1 It is C(O)CH3.

87. The method according to any one of claims 84 to 86, further comprising the step of preparing the compound of formula (V'), comprising making the compound of formula (IX) R 6 -X3a-X4a-R 3 (IX) and a compound of formula (X) R 2 -X5a-X6a-R 5 (X) reacting to form an amide bond between X4a and X5a; where R 2 is H, and R 3 OH or OP 2 ； R 5 OH or OP 2 ; R 6 H or P 1 , P 1 is an amino protecting group, and each P 2 is independently a carboxyl protecting group.

88. The method of claim 87, wherein the compound of formula (IX) is R 6 -X4a-R 3 , where R 3 is OH, and R 6 P 1 And P 1 is an amino protecting group.

89. The method of claim 87 or 88, wherein the amide bond is formed using an ammonium coupling reagent.

90. The method of claim 87 or 88, wherein the amide bond is formed in the presence of O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate (TBTU) and diisopropylethylamine (DIPEA).

91. The method of any one of claims 87 to 90, wherein R 5 For OP 2 , and P 2 C 1-6 alkyl.

92. The method of any one of claims 87 to 91, wherein R 6 P 1 , and P 1 It is Fmoc.

93. The method according to any one of claims 87 to 92, further comprising the step of preparing the compound of formula (X), comprising reacting the compound of formula R 6 -X5a-R 3 The compound of formula R 2 -X6a-R 5 to form an amide bond between X5a and X6a, wherein R 2 H, R 3 OH, R 5 For OP 2 , R 6 P 1 , P 1 is an amino protecting group, and P 2 A carboxyl protecting group.

94. The method of claim 93, wherein the amide bond is formed using a carbodiimide coupling reagent, optionally in the presence of an additive.

95. The method of claim 93, wherein the amide bond is formed in the presence of N-ethyl-N'-dimethylaminopropylcarbodiimide (EDCI) and 1-hydroxy-7-azabenzotriazole (HOAt).

96. The method of any one of claims 93 to 95, wherein R 5 For OP 2 , and P 2 C 1-6 alkyl.

97. The method of any one of claims 93 to 96, wherein R 6 P 1 , and P 1 For Cbz.

98. The method according to any one of claims 55 to 97, further comprising the step of preparing the compound of formula (IV) comprising: R 6 -X11a-X12a-R 3 (VII) and a compound of formula (VIII) R 2 -X13a-X14a-X15a-X16a-R 4 (VIII) reacting to form an amide bond between X12a and X13a; in R 2 is H; R 3 OH or OP 2 ; R 4 NH2 or NHP 1 ; R 6 H or P 1 ; Each P 1 are independently amino protecting groups; and P 2 A carboxyl protecting group.

99. The method of claim 98, wherein the amide bond is formed using a carbodiimide coupling reagent, optionally in the presence of an additive.

100. The method of claim 98, wherein the amide bond is formed in the presence of N-ethyl-N'-dimethylaminopropylcarbodiimide (EDCI) and 1-hydroxy-7-azabenzotriazole (HOAt).

101. The method of any one of claims 98 to 100, wherein R 4 is NH2.

102. The method of any one of claims 98 to 101, wherein R 6 P 1 , and P 1 It is Fmoc.

103. The method according to any one of claims 98 to 102, further comprising the step of preparing the compound of formula (VII) by reacting R 6 -X11a-R 3 Compounds with R 2 -X12a-R 5 to form an amide bond between X11a and X12a, wherein R 2 H, R 3 OH, R 5 OH or OP 2 , R 6 P 1 , P 1 is an amino protecting group, and P 2 A carboxyl protecting group.

104. The method according to any one of claims 98 to 103, further comprising the step of preparing the compound of formula (VIII), comprising: R 2 -X15a-X16a-R 4 (XIII) With a compound of formula (XIV): R 6 -X13a-X14a-R 3 (XIV) reacts to form an amide bond between X14a and X15a; wherein R 2 is H; R 3 OH or OP 2 ; R 4 NH2 or NHP 1 ; R 6 H or P 1 ; Each P 1 are independently amino protecting groups; and P 2 A carboxyl protecting group.

105. The method of claim 104, wherein the amide bond is formed using a carbodiimide coupling reagent, optionally in the presence of an additive.

106. The method of claim 104, wherein the amide bond is formed in the presence of N-ethyl-N'-dimethylaminopropylcarbodiimide (EDCI), 1-hydroxy-7-azabenzotriazole (HOAt), and 1,4-diazabicyclo[2.2.2]octane (DABCO).

107. The method of any one of claims 104 to 106, wherein R 4 is NH2.

108. The method of any one of claims 104 to 107, wherein R 6 P 1 , and P 1 For Cbz.

109. The method according to any one of claims 104 to 108, further comprising the step of preparing the compound of formula (XII) by reacting R 6 -X15a-R 3 Compounds with R 2 -X16a-R 5 to form an amide bond between X15a and X16a; wherein R 2 is H, and R 3 OH, R 5 OH or OP 2 ; and R 6 H or P 1 .

110. The method of claim 109, wherein the amide bond is formed in the presence of 1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxide hexafluorophosphate (HATU) and N-methyl-2-pyrrolidone (NMP).

111. The method according to any one of claims 104 to 110, further comprising the step of preparing the compound of formula (XIV) by reacting R 6 -X13a-R 3 Compounds with R 2 -X14a-R 5 The compound of 13a to 14a is reacted to form an amide bond between X13a and X14a.

112. The method of claim 111, wherein the amide bond is formed in the presence of pivaloyl chloride.

113. The method according to any one of claims 77 to 112, further comprising the step of preparing a compound of formula (VI) comprising making a compound of formula (XI): R 2 -X8a-X9a-X10a-R 5 (XI) With R 6 -X7a-R 3 reacts to form an amide bond between X7a and X8a; wherein R 2 is H; R 3 OH or OP 2 ; R 5 OH or OP 2 ; R 6 H or P 1 ;and P 1 is an amino protecting group; and Each P 2 is independently a carboxyl protecting group.

114. The method of claim 113, wherein the amide bond is formed using a carbodiimide coupling reagent, optionally in the presence of an additive.

115. The method of claim 113, wherein the amide bond is formed in the presence of N-ethyl-N'-dimethylaminopropylcarbodiimide (EDCI) and ethyl cyanohydroxyiminoacetate (Oxyma Pure).

116. The method according to any one of claims 113 to 115, wherein R 5 P 1 , and P 1 C 1-6 alkyl.

117. The method according to any one of claims 113 to 116, wherein R 6 It is Fmoc.

118. The process according to any one of claims 113 to 117, further comprising the step of preparing a compound of formula (XI) comprising reacting a compound of formula (XII): R 2 -X9a-X10a-R 5 (XII) With R 6 -X8a-R 3 reacts to form an amide bond between X8a and X9a; wherein R 2 is H; R 3 OH or OP 2 ; R 5 OH or P 2 ; R 6 H or P 1 ;and P 1 is an amino protecting group; and Each P 2 is independently a carboxyl protecting group.

119. The method of claim 118, wherein the amide bond is formed using a carbodiimide coupling reagent, optionally in the presence of an additive.

120. The method of claim 118 or 119, wherein the amide bond is formed in the presence of N-ethyl-N'-dimethylaminopropylcarbodiimide (EDCI) and ethyl cyanohydroxyiminoacetate (Oxyma Pure).

121. The method according to any one of claims 118 to 120, wherein R 5 P 1 , and P 1 C 1-6 alkyl.

122. The method of any one of claims 118 to 121, wherein R 6 It is Fmoc.

123. The method according to any one of claims 118 to 122, further comprising the step of preparing the compound of formula (XII) by reacting R 6 -X9a-R 3 Compounds with R 2 -X10a-R 5 to form an amide bond between X9a and X10a, wherein R 2 H, R 3 OH, R 5 OH or P 2 , R 6 H or P 1 , P 1 is an amino protecting group, and P 2 A carboxyl protecting group.

124. The method of claim 123, wherein the amide bond is formed using a carbodiimide coupling reagent, optionally in the presence of an additive.

125. The method of claim 123 or 124, wherein the amide bond is formed in the presence of N-ethyl-N'-dimethylaminopropylcarbodiimide (EDCI) and ethyl cyanohydroxyiminoacetate (Oxyma Pure).

126. The method of any one of claims 123 to 125, wherein R 5 P 1 , and P 1 C 1-6 alkyl.

127. The method of any one of claims 123 to 126, wherein R 6 It is Fmoc.

128. The method of any one of claims 55 to 127, wherein the compound of formula (III) is: Ac-Pen-Asn-Thr-Trp(7-Me)-Lys(Ac)-Pen-Tyr(2ea)-OH, wherein the amino groups on Asn and Tyr(2ea) and the hydroxyl group on Thr are each optionally protected; and the compound of formula (IV) is: H-2Nal-Gly(THP)-Glu-Asn-3Pal-Sarc-NHP 1 , wherein the amino group on Asn and the hydroxyl group on Glu are each optionally protected.

129. The method of any one of claims 55 to 128, wherein the compound of formula (II) is: Ac-Pen-Asn-Thr-Trp(7Me)-Lys(Ac)-Pen-Tyr(2ea)-2Nal-Gly(THP)-Glu-Asn-3Pal-Sarc-NHP 1 , wherein the amino groups on each of Asn and Tyr (2ea) and the hydroxyl groups on Thr and Glu are each protected.

130. The method of claim 66, wherein the compound of formula (I) is: Ac-Pen-Asn-Thr-Trp(7Me)-Lys(Ac)-Pen-Tyr(2ea)-2Nal-Gly(THP)-Glu-Asn-3Pal-Sarc-NH2.

131. The method of any one of claims 1 to 130, wherein the method produces the single cyclic peptide in an amount greater than 1 Kg.

132. The method of any one of claims 1 to 131, wherein the method produces the single cyclic peptide in an amount greater than 10 Kg.

133. The method of any one of claims 1 to 132, wherein the method produces the single cyclic peptide in an amount of 10 Kg to 60 Kg.

134. A compound prepared according to the method of any one of claims 1 to 133.

135. A compound of formula (III): in R 1 H or C 1-20 Alkanoyl; R 3 OH or OP 2 ; P 2 is a carboxyl protecting group; X3a does not exist or is any amino acid residue; X4a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide); X5a is Cit, Glu, Gly, substituted Gly, Leu, Ile, β-Ala, Ala, Lys, Asn, Pro, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, Lys(Ac), α-MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), Gln, Asp or Cys; X6a is Thr, 2-aminoisobutyric acid, Asp, Dab, Gly, Pro, Ser, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, α-MeThr, α-MeSer, or Val; X7a is unsubstituted Trp, or Trp substituted with cyano, halo, alkyl, substituted or unsubstituted aryl, haloalkyl, hydroxyl or alkoxy; X8a is Gln, α-Me-Lys, α-MeLeu, α-MeLys(Ac), β-homoGln, Cit, Glu, Phe, Asn, Thr, Val, 2-aminoisobutyric acid, α-MeGln, α-MeAsn, Lys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), 1Nal, 2-Nal or Trp; X9a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide); X10a is unsubstituted Phe, or Phe substituted with halo, alkyl, haloalkyl, hydroxy, alkoxy, carboxyl, carboxamido, 2-aminoethoxy, or 2-acetylaminoethoxy; and The compound is cyclized via a Pen-Pen disulfide bond between X4a and X9a; or the compound is cyclized via an Abu-Cys or Abu-Pen thioether bond between X4a and X9a.

136. The compound according to claim 135, wherein R 1 It is C(O)CH3.

137. The compound of claim 135 or 136, wherein the compound of formula (III) is: R 1 -Pen-Asn-Thr-Trp(7-Me)-Lys(Ac)-Pen-Tyr(2ea)-R 3 ; wherein the thiol group on each Pen, the amino groups on Asn and Tyr(2ea), and the hydroxyl group on Thr are each optionally protected.

138. A compound of formula (IV): R 2 -X11a-X12a-X13a-X14a-X15a-X16a-R 4 (IV) in R 2 is H; R 4 For NHP 1 or NH2; P 1 is an amino protecting group; X11a is 2-Nal, unsubstituted Trp, or Trp substituted with cyano, halo, alkyl, haloalkyl, hydroxy, alkoxy, Phe(2-Me), Phe(3-Me), Phe(4-Me), Phe(3,4-dimethoxy), or 1Nal; X12a is 4-amino-4-carboxytetrahydropyran (Gly(THP)), α-MeLys, α-MeLeu, α-MeArg, α-MePhe, α-MeLeu, α-MeLys, α-MeAsn, α-MeTyr, Ala, cyclohexylAla, Lys, or 2-aminoisobutyric acid; X13a is 2-aminoisobutyric acid, Glu, Cit, Gln, Lys(Ac), α-MeArg, α-MeGlu, α-MeLeu, α-MeLys, α-Me-Asn, α-MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), or Lys; or X13a is Lys, pegylated Lys, b-homoGlu, or Lys(Y2-Ac), wherein Y2 is an amino acid residue; X14a is Asn, 2Nal, 2-aminoisobutyric acid, Arg, Cit, Asp, Phe, Gly, Lys, Leu, Ala, (D)Ala, β-Ala, His, Thr, n-Leu, Gln , Ser, (D)Ser, Tic, Trp, α-MeGln, α-MeAsn, α-MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac) or Lys(Ac); X15a is Ala, β-Ala, Arg, Asn, Asp, Cit, Cys, Glu, Gln, Gly, substituted or unsubstituted His, (D)His, Ile, Lue, (D)Lue, Lys, (D)Lys, Met, 2Pal, 3Pal or 4Pal, Phe, Pro, 5-Pyal, 2Quin, 3Quin, Ser, Thr, Trp, Tyr, Val, or Leu; X16a is absent or is Sarc, aMeLeu, (D)NMeTyr, His, (D)Thr, bAla, Pro, or (D)Pro.

139. The compound of claim 138, wherein the compound of formula (IV) is: R 2 -2Nal-Gly(THP)-Glu-Asn-3Pal-Sarc-R 4 ; wherein the hydroxyl group on Glu and the amino group on Asn are each optionally protected.

140. A compound of formula (III'): R 1 -X3a-X4a-X5a-X6a-X7a-X8a-X9a-X10a-R 5 (III') in R 1 H or C 1-20 Alkanoyl; R 5 OH or OP 2 ; P 2 is a carboxyl protecting group; X3a does not exist or is any amino acid residue; X4a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide); X5a is Cit, Glu, Gly, substituted Gly, Leu, Ile, β-Ala, Ala, Lys, Asn, Pro, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, Lys(Ac), α-MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), Gln, Asp or Cys; X6a is Thr, 2-aminoisobutyric acid, Asp, Dab, Gly, Pro, Ser, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, α-MeThr, α-MeSer, or Val; X7a is unsubstituted Trp, or Trp substituted with cyano, halo, alkyl, substituted or unsubstituted aryl, haloalkyl, hydroxyl or alkoxy; X8a is Gln, α-Me-Lys, α-MeLeu, α-MeLys(Ac), β-homoGln, Cit, Glu, Phe, Asn, Thr, Val, 2-aminoisobutyric acid, α-MeGln, α-MeAsn, Lys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), 1Nal, 2-Nal or Trp; X9a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide); X10a is unsubstituted Phe, or Phe substituted with halo, alkyl, haloalkyl, hydroxy, alkoxy, carboxyl, carboxamido, 2-aminoethoxy, or 2-acetylaminoethoxy.

141. The compound of claim 140, wherein R 1 is C(O)CH3, and R 5 For OH.

142. The compound of claim 140 or 141, wherein the compound of formula (III') is: R 1 -Pen-Asn-Thr-Trp(7-Me)-Lys(Ac)-Pen-Tyr(2ea)-R 5 ; wherein the thiol group on each Pen, the amino group on Asn, and the hydroxyl groups on Thr and Tyr(2ea) are each optionally protected.

143. A compound of formula (V): R 1 -X3a-X4a-X5a-X6a-R 3 (V) where R 1 H or C 1-20 Alkanoyl; R 3 OH or OP 2 ; P 2 is a carboxyl protecting group; X3a does not exist or is any amino acid residue; X4a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide); X5a is Cit, Glu, Gly, substituted Gly, Leu, Ile, β-Ala, Ala, Lys, Asn, Pro, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, Lys(Ac), α-MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), Gln, Asp or Cys; X6a is Thr, 2-aminoisobutyric acid, Asp, Dab, Gly, Pro, Ser, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, α-MeThr, α-MeSer or Val.

144. The compound according to claim 143, wherein R 1 It is C(O)CH3.

145. The compound of claim 143 or 144, wherein the compound of formula (V) is: R 1 -Pen-Asn-Thr-R 3 ; wherein the hydroxyl group on Thr and the amino group on Asn are each optionally protected.

146. A compound of formula (V'): R 7 -X3a-X4a-X5a-X6a-R 5 (V') where R 5 OH or OP 2 ; R 7 H or P 1 ; P 1 is an amino protecting group; P 2 is a carboxyl protecting group; X3a does not exist or is any amino acid residue; X4a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide); X5a is Cit, Glu, Gly, substituted Gly, Leu, Ile, β-Ala, Ala, Lys, Asn, Pro, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, Lys(Ac), α-MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), Gln, Asp or Cys; X6a is Thr, 2-aminoisobutyric acid, Asp, Dab, Gly, Pro, Ser, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, α-MeThr, α-MeSer or Val.

147. The compound of claim 146, wherein the compound of formula (V') is: R 7 -Pen-Asn-Thr-R 5 ; wherein the thiol group on Pen and the hydroxyl group on Thr are optionally protected.

148. A compound of formula (VI): R 2 -X7a-X8a-X9a-X10a-R 5 (VI) where R 2 is H; R 5 NH2 or NHP 1 ; P 1 is an amino protecting group; X7a is unsubstituted Trp, or Trp substituted with cyano, halo, alkyl, substituted or unsubstituted aryl, haloalkyl, hydroxyl or alkoxy; X8a is Gln, α-Me-Lys, α-MeLeu, α-MeLys(Ac), β-homoGln, Cit, Glu, Phe, Asn, Thr, Val, 2-aminoisobutyric acid, α-MeGln, α-MeAsn, Lys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), 1Nal, 2-Nal or Trp; X9a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide); X10a is unsubstituted Phe, or Phe substituted with halo, alkyl, haloalkyl, hydroxy, alkoxy, carboxyl, carboxamido, 2-aminoethoxy, or 2-acetylaminoethoxy.

149. The compound of claim 148, wherein the compound of formula (VI) is: R 2 -Trp(7-Me)-Lys(Ac)-Pen-Tyr(2ea)-R 5 ; wherein the thiol group on Pen and the amino group on Tyr(2ea) are each optionally protected.

150. A compound of formula (VII): R 6 -X11a-X12a-R 3 (VII) where R 3 OH or OP 2 ; R 6 H or P 1 ; P 1 is an amino protecting group; P 2 is a carboxyl protecting group; X11a is 2-Nal, unsubstituted Trp, or Trp substituted with cyano, halo, alkyl, haloalkyl, hydroxy, alkoxy, Phe(2-Me), Phe(3-Me), Phe(4-Me), Phe(3,4-dimethoxy), or 1Nal; X12a is 4-amino-4-carboxy-tetrahydropyran (Gly(THP)), α-MeLys, α-MeLeu, α-MeArg, α-MePhe, α-MeLeu, α-MeLys, α-MeAsn, α-MeTyr, Ala, cyclohexylAla, Lys or 2-aminoisobutyric acid.

151. The compound of claim 150, wherein the compound of formula (VII) is: R 6 -2Nal-Gly(THP)-R 3 。 152. A compound of formula (VIII): R 2 -X13a-X14a-X15a-X16a-R 5 (VIII) where R 2 is H; R 5 NH2 or NHP 1 ; P 1 is an amino protecting group; X13a is 2-aminoisobutyric acid, Glu, Cit, Gln, Lys(Ac), α-MeArg, α-MeGlu, α-MeLeu, α-MeLys, α-Me-Asn, α-MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), or Lys; or X13a is Lys, pegylated Lys, b-homoGlu, or Lys(Y2-Ac), wherein Y2 is an amino acid residue; X14a is Asn, 2Nal, 2-aminoisobutyric acid, Arg, Cit, Asp, Phe, Gly, Lys, Leu, Ala, (D)Ala, β-Ala, His, Thr, n-Leu, Gln , Ser, (D)Ser, Tic, Trp, α-MeGln, α-MeAsn, α-MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac) or Lys(Ac); X15a is Ala, β-Ala, Arg, Asn, Asp, Cit, Cys, Glu, Gln, Gly, substituted or unsubstituted His, (D)His, Ile, Lue, (D)Lue, Lys, (D)Lys, Met, 2Pal, 3Pal or 4Pal, Phe, Pro, 5-Pyal, 2Quin, 3Quin, Ser, Thr, Trp, Tyr, Val, or Leu; X16a is absent or is Sarc, aMeLeu, (D)NMeTyr, His, (D)Thr, bAla, Pro, or (D)Pro.

153. The compound of claim 152, wherein the compound of formula (VIII) is: R 2 -Glu-Asn-3Pal-Sarc-R 5 ; wherein the hydroxyl group on Glu and the amino group on Asn are each optionally protected.

154. A compound of formula (IX): R 6 -X3a-X4a-R 3 (IX) where R 3 OH or OP 2 ; R 6 H or P 1 ; P 1 is an amino protecting group; P 2 is a carboxyl protecting group; X3a does not exist or is any amino acid residue; X4a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen or Pen(sulfoxide).

155. The compound of claim 154, wherein the compound of formula (IX) is: R 6 -Pen-R 3 ; wherein the thiol group on Pen is optionally protected.

156. A compound of formula (X): R 2 -X5a-X6a-R 5 (X) where R 2 is H; R 5 NH2 or NHP 1 ; P 1 is an amino protecting group; X5a is Cit, Glu, Gly, substituted Gly, Leu, Ile, β-Ala, Ala, Lys, Asn, Pro, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, Lys(Ac), α-MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), Gln, Asp or Cys; X6a is Thr, 2-aminoisobutyric acid, Asp, Dab, Gly, Pro, Ser, α-MeGln, α-MeLys, α-MeLeu, α-MeAsn, α-MeThr, α-MeSer or Val.

157. The compound of claim 156, wherein the compound of formula (X) is: R 2 -Asn-Thr-R 5 ; wherein the hydroxyl group on Thr is optionally protected.

158. A compound of formula (XI): R 2 -X8a-X9a-X10a-R 5 (XI) where R 2 is H; R 5 NH2 or NHP 1 ; P 1 is an amino protecting group; X8a is Gln, α-Me-Lys, α-MeLeu, α-MeLys(Ac), β-homoGln, Cit, Glu, Phe, Asn, Thr, Val, 2-aminoisobutyric acid, α-MeGln, α-MeAsn, Lys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), 1Nal, 2-Nal or Trp; X9a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide); X10a is unsubstituted Phe, or Phe substituted with halo, alkyl, haloalkyl, hydroxy, alkoxy, carboxyl, carboxamido, 2-aminoethoxy, or 2-acetylaminoethoxy.

159. The compound of claim 158, wherein the compound of formula (XI) is: R 2 -Lys(Ac)-Pen-Phe(4-(2-aminoethoxy))-R 5 ; wherein the thiol group on Pen and the amino group on Phe(4-(2-aminoethoxy)) are each optionally protected.

160. A compound of formula (XII): R 2 -X9a-X10a-R 5 where R 2 is H; R 5 NH2 or NHP 1 ; P 1 is an amino protecting group; X9a is Abu, Cys, (D)Cys, α-MeCys, (D)Pen, Pen, or Pen(sulfoxide); X10a is unsubstituted Phe, or Phe substituted with halo, alkyl, haloalkyl, hydroxy, alkoxy, carboxyl, carboxamido, 2-aminoethoxy, or 2-acetylaminoethoxy.

161. The compound of claim 160, wherein the compound of formula (XII) is: R 2 -Pen-Tyr(2ea)-R 5 4 wherein the thiol group on Pen and the amino group on Try(2ea) are each optionally protected.

162. A compound of formula (XIII): R 2 -X15a-X16a-R 4 (XII) where R 2 is H; R 4 For NHP 1 or NH2; P 1 is an amino protecting group; X15a is Ala, β-Ala, Arg, Asn, Asp, Cit, Cys, Glu, Gln, Gly, substituted or unsubstituted His, (D)His, Ile, Lue, (D)Lue, Lys, (D)Lys, Met, 2Pal, 3Pal or 4Pal, Phe, Pro, 5-Pyal, 2Quin, 3Quin, Ser, Thr, Trp, Tyr, Val, or Leu; X16a is absent or is Sarc, aMeLeu, (D)NMeTyr, His, (D)Thr, bAla, Pro, or (D)Pro.

163. The compound of claim 162, wherein the compound of formula (XIII) is: R 2 -3Pal-Sarc-R 4 。 164. A compound of formula (XIV): R 6 -X13a-X14a-R 3 (XIV) where R 3 OH or OP 2 ; R 6 H or P 1 ; P 1 is an amino protecting group; P 2 is a carboxyl protecting group; X13a is 2-aminoisobutyric acid, Glu, Cit, Gln, Lys(Ac), α-MeArg, α-MeGlu, α-MeLeu, α-MeLys, α-Me-Asn, α-MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac), or Lys; or X13a is Lys, pegylated Lys, b-homoGlu, or Lys(Y2-Ac), wherein Y2 is an amino acid residue; X14a is Asn, 2Nal, 2-aminoisobutyric acid, Arg, Cit, Asp, Phe, Gly, Lys, Leu, Ala, (D)Ala, β-Ala, His, Thr, n-Leu, Gln, Ser, (D) Ser, Tic, Trp, α-MeGln, α-MeAsn, α-MeLys(Ac), Dab(Ac), Dap(Ac), homo-Lys(Ac) or Lys(Ac).

165. The compound of claim 164, wherein the compound of formula (XIV) is: R 6 -Glu-Asn-R 3 ; wherein the hydroxyl group on Glu is optionally protected.

166. A compound of formula (AV), (A-VI) or (A-VII) in: P 11 is H, Fmoc, Cbz or BOC; P 12 is H, Fmoc, Cbz or BOC; P 13 is H, Fmoc, Cbz or BOC; P 14 H or C (1-4) alkyl; or a pharmaceutically acceptable salt thereof.

167. A compound of formula (A-II), (A-III) or (A-IV) in: P 4 is H, Fmoc, Cbz or BOC; P 5 is H, trityl or Acm; P 6 H or C (1-4) alkyl; P 7 is H, Fmoc, Cbz or BOC; P 8 is H or Ac; P 9 is H, Fmoc, Cbz or BOC; P 10 is H, Fmoc, Cbz or BOC; or a pharmaceutically acceptable salt thereof.

168. A compound of formula (AI) in: P 0 H or C (1-4) alkyl; P 1 is H, tert-butyl, Bn or Bz; P 2 is H, trityl or Acm; P 3 is H, Fmoc, Cbz or BOC; or a pharmaceutically acceptable salt thereof.

169. The compound of claim 168, which is or a pharmaceutically acceptable salt thereof.

170. The compound of claim 167, which has the structure of formula (A-II) in: P 4 is H, Fmoc, Cbz or BOC; P 5 is H, trityl or Acm; P 6 H or C (1-4) alkyl; P 7 is H, Fmoc, Cbz or BOC; or a pharmaceutically acceptable salt thereof.

171. The compound of claim 170, wherein the compound of formula (A-II) is: or a pharmaceutically acceptable salt thereof.

172. The compound of claim 167, which has the structure of formula (A-III) in: P 5 is H, trityl or Acm; P 6 H or C (1-4) alkyl; P 7 is H, Fmoc, Cbz or BOC; P 8 is H or Ac; P 9 is H, Fmoc, Cbz or BOC; or a pharmaceutically acceptable salt thereof.

173. The compound of claim 172, wherein the compound of formula (A-III) is: or a pharmaceutically acceptable salt thereof.

174. The compound of claim 167, which has the structure of formula (A-IV) in: P 6 H or C (1-4) alkyl; P 7 is H, Fmoc, Cbz or BOC; P 8 is H or Ac; P 10 is H, Fmoc, Cbz or BOC; or a pharmaceutically acceptable salt thereof.

175. The compound of claim 174, which is or a pharmaceutically acceptable salt thereof.

176. The compound of claim 166, which has the structure of Formula (AV): in: P 11 is H, Fmoc, Cbz or BOC; or a pharmaceutically acceptable salt thereof.

177. The compound of claim 176, which is or a pharmaceutically acceptable salt thereof.

178. The compound of claim 166, having the structure of formula (A-VI) in: P 12 is H, Fmoc, Cbz or BOC; or a pharmaceutically acceptable salt thereof.

179. The compound of claim 178, which is or a pharmaceutically acceptable salt thereof.

180. The compound of claim 166, having the structure of formula (A-VII) in: P 13 is H, Fmoc, Cbz or BOC; P 14 H or C (1-4) alkyl; or a pharmaceutically acceptable salt thereof.

181. The compound of claim 180, which is or a pharmaceutically acceptable salt thereof.

182. A compound of formula (A-VIII) in: P 15 is H, Fmoc, Cbz or BOC; P 16 H or C (1-4) alkyl; or a pharmaceutically acceptable salt thereof.

183. The compound of claim 182, which is or a pharmaceutically acceptable salt thereof.

184. A compound of formula (A-IX) in: P 15 is H, Fmoc, Cbz or BOC; P 14 H or C (1-4) alkyl; or a pharmaceutically acceptable salt thereof.

185. The compound of claim 184, which is or a pharmaceutically acceptable salt thereof.

186. A compound of formula (AX) in: P 1 are H, tert-butyl, Bn, and Bz; P 2 is H, trityl or Acm; P 3 is H, Fmoc, Cbz or BOC; P 5 is H, trityl or Acm; P 6 H or C (1-4) alkyl; P 7 is H, Fmoc, Cbz or BOC; P 8 is H or Ac; or a pharmaceutically acceptable salt thereof.

187. The compound of claim 186, which is or a pharmaceutically acceptable salt thereof.

188. A compound of formula (A-XI) in: P 1 is H, tert-butyl, Bn or Bz; P 3 is H, Fmoc, Cbz or BOC; P 6 H or C (1-4) alkyl; P 7 is H, Fmoc, Cbz or BOC; P 8 is H or Ac; or a pharmaceutically acceptable salt thereof.

189. The compound of claim 188, which is or a pharmaceutically acceptable salt thereof.

190. A method for preparing compound 26, comprising reacting the Ac-[1-7]-OH- ring with H-[8-13]-NH2:

191. The method of claim 190, wherein H[8-13]NH2 is formed by reacting Fmoc-2-Nal-THPGly-OH with H-Glu(OtBu)-Asn-3-Pal-Sar-NH2:

192. The method of claim 191, wherein Fmoc-2-Nal-THPGly-OH is formed by reacting H-THPGly-OH with Fmoc-2-Nal-OH:

193. The method of claim 191, wherein Z-Glu(OtBu)-OH is reacted with N-hydroxysuccinimide and diisopropylcarbodiimide, followed by reaction with H-Asn-3-Pal-Sar-NH2 to form Cbz-Glu(OtBu)-Asn-3-Pal-Sar-NH2, which is then catalytically hydrogenated to form H-Glu(OtBu)-Asn-3-Pal-Sar-NH2:

194. The method of claim 193, wherein Z-Asn-OH is reacted with N-hydroxysuccinimide and diisopropylcarbodiimide, followed by reaction with H-3-Pal-Sar-NH2 to form Cbz-[11-13]-NH2, which is then catalytically hydrogenated to form H-Asn-3-Pal-Sar-NH2:

195. The method of claim 194, wherein the H-3-Pal-Sar-NH2 is formed by reacting Boc-3-Pal-OH with pivaloyl chloride in the presence of pyridine and N-methylmorpholine, followed by reaction with H-Sar-NH2 to form Boc-3-Pal-Sar-NH2, and then acid-mediated removal of the butoxycarbonyl group:

196. A method for preparing Ac-[1-7]-OMe, comprising reacting Ac-Pen(Trt)-Asn-Thr(tBu)-OH with H-7Me-Trp-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe in the presence of diisopropylcarbodiimide and Oxyma B, followed by reaction with iodine in the presence of potassium iodide:

197. The method of claim 196, wherein H-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe is reacted with Fmoc-Trp(7Me)-OH in the presence of N,N,N'N'-tetramethyl-O-(benzotriazol-1-yl)uronium tetrafluoroborate and diisopropylethylamine to form Fmoc-7Me-Trp-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe, which is then reacted with 1,8-diazabicyclo[5,4,0]undec-7-ene to form H-7Me-Trp-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-Ome:

198. The method of claim 197, wherein H-Pen(Acm)-Tyr(2-Boc-ea)-OMe is reacted with Fmoc-Lys(Ac)-OH in the presence of N,N,N'N'-tetramethyl-O-(benzotriazol-1-yl)uronium tetrafluoroborate and diisopropylethylamine to form Fmoc-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe, which is then reacted with 1,8-diazabicyclo[5,4,0]undec-7-ene to form H-Lys(Ac)-Pen(Acm)-Tyr(2-Boc-ea)-OMe:

199. The method of claim 198, wherein H-Tyr(2-Boc-ea)-OMe is reacted with Fmoc-Pen(Acm)-OH in the presence of Oxyma Pure and diisopropylcarbodiimide to form Fmoc-Pen(Acm)-Tyr(2-Boc-ea)-OMe, which is then reacted with 1,8-diazabicyclo[5,4,0]undec-7-ene to form H-Pen(Acm)-Tyr(2-Boc-ea)-OMe:

200. The method of claim 199, wherein H-Asn-Thr(tBu)-OMe is reacted with Fmoc-Pen(Trt)-OH in the presence of N,N,N'N'-tetramethyl-O-(benzotriazol-1-yl)uronium tetrafluoroborate and diisopropylethylamine to form Fmoc-Pen(Trt)-Asn-Thr(tBu)-OMe, followed by reaction with 1,8-diazabicyclo[5,4,0]undec-7-ene to form H-Pen(Trt)-Asn-Thr(tBu)-OMe, followed by reaction with acetic anhydride to form Ac-Pen(Trt)-Asn-Thr(tBu)-OMe, followed by reaction with lithium hydroxide to form Ac-Pen(Trt)-Asn-Thr(tBu)-OH:

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