Method for producing peptide compound containing n-substituted-amino acid residue

Abstract

The present invention addresses the problem of providing a method for producing a high-purity peptide compound with high efficiency and high yield. It is found that the problem can be solved by supporting a peptide on a resin for solid-phase synthesis use prior to a first extension reaction in a solid-phase method.

Description

Method for producing peptide compounds containing N-substituted amino acid residues

[0001] The present invention relates to a method for producing peptide compounds containing N-substituted amino acid residues.

[0002] Medium-sized molecules (molecular weight 500-2000) have attracted attention as a modality that can realize drug discovery against tough targets, such as inhibition of protein-protein interactions (Non-Patent Document 1).

[0003] Peptides generally have low drug-likeness (metabolic stability and membrane permeability), making their development as pharmaceuticals difficult. However, in recent years, it has been discovered that peptide cyclization and the use of unnatural amino acids, such as N-methylamino acids, in peptides can improve metabolic stability and membrane permeability (Non-Patent Documents 2 and 3).

[0004] Among cyclic peptides containing unnatural amino acids, cyclic peptides containing N-substituted amino acids in particular have become known to have drug-like properties (Patent Document 1).

[0005] It has also been suggested that library compounds of cyclic peptides containing unnatural amino acids are useful for creating inhibitors of protein-protein interactions (Non-Patent Document 4).

[0006] The conditions under which cyclic peptides containing unnatural amino acids are drug-like molecules with sufficient membrane permeability and metabolic stability to be used as pharmaceuticals have also been clarified, and cyclic peptides are attracting further attention as a pharmaceutical modality (Patent Documents 2 and 3).

[0007] On the other hand, the production of peptides containing N-methyl amino acids in the sequence has been problematic due to low reactivity in condensation reactions caused by steric hindrance of the N-methyl group, and reduced yields of the target product due to racemization of the α-position of the amino acid residue. Furthermore, many issues have been reported, such as the susceptibility of the amide bond at the N-methyl amino acid residue site to cleavage under acidic conditions and the susceptibility to loss due to elimination of the two amino acid residues at the N-terminus resulting from diketopiperazine formation. Therefore, it is widely recognized that the synthesis of peptides containing N-methyl amino acids is more difficult than that of natural peptides (Non-Patent Document 5).

[0008] Peptide synthesis is achieved by extending the peptide to the desired sequence through the formation of an amide bond. More specific methods include liquid-phase and solid-phase methods (Non-Patent Document 6).

[0009] Among these, the solid-phase method includes the steps of: preparing a solid-phase synthesis resin in which the C-terminus of an amino acid or peptide is supported on the solid-phase synthesis resin using an atomic group linked to the polymer resin (solid-phase synthesis resin) as a linker (supporting step); deprotecting the N-terminal amino group of the amino acid or peptide supported on the solid-phase synthesis resin; a condensation step in which an N-terminally protected amino acid is introduced by a condensation reaction as the next sequence; an elongation step in which amino acid residues are linked to a peptide chain having the desired sequence by repeating these deprotection and condensation steps until the desired sequence is obtained; and cleaving the peptide having the desired sequence from the solid-phase synthesis resin (resin removal step). The N-terminally protected amino acid used in the elongation step is generally an amino acid whose N-terminal amino group is protected with an Fmoc group or a Boc group (Non-Patent Documents 7 and 8).

[0010] Resins for solid-phase synthesis are broadly classified by the atomic group that serves as a linker bonded to the polymer used in the resin, and those for solid-phase synthesis to which a linker atomic group containing a trityl skeleton or a benzyl skeleton is bonded are commonly used. More specifically, CTC resin, Wang resin, SASRIN resin, Rink Amide resin, etc. are representative examples (Non-Patent Document 8).

[0011] The depolymerization step is typically performed under acidic conditions, but the ease of depolymerization depends on the stability of the linker moiety against acid. For example, depolymerization of peptides from CTC resins, which can support peptide residues using a trityl backbone as a linker, can be performed using weakly acidic reagents. On the other hand, depolymerization of peptides from Wang resins, which can support peptides using a benzyl backbone as a linker, requires strong acidic conditions (Non-Patent Document 8).

[0012] CTC resin allows peptide deprotection under milder acidic conditions. Therefore, peptides with protecting groups that are easily removed under acidic conditions can be selectively deprotected without deprotecting the protecting groups. Therefore, CTC resin is useful for producing peptides protected by such protecting groups (Non-Patent Document 9). On the other hand, in solid-phase peptide synthesis using CTC resin, because peptides can be deprotected from the CTC resin under mild conditions, the covalent bond between the amino acid or peptide supported on the CTC resin and the resin linker can be cleaved under condensation reaction conditions, resulting in a decrease in the yield of the desired peptide (also known as premature cleavage, premature peptide release, or premature acidolytic cleavage) (Non-Patent Documents 10 and 11).

[0013] International Publication No. WO 2013 / 100132 International Publication No. WO 2018 / 115864 International Publication No. WO 2020 / 122182

[0014] Future Med. Chem., 2009, 1, 1289-1310. Acc. Chem. Res., 2008, 41, 1331-1342. Angew. Chem. Int. Ed., 2013, 52, 254-269. Chem. Rev., 2019, 119, 10360-10391. J. Peptide Res., 2005, 65, 153-166. Amino Acids, Peptides and Proteins in Organic Chemistry: Building Blocks, Catalysis and Coupling Chemistry, Volume 3, 2011. Amino Acids, 2018, 50, 39-68. Solid phase peptide synthesis (published by Bachem) [Retrieved November 6, 2020], Internet <URL: https: / / www.bachem.com / fileadmin / user_upload / pdf / Catalogs_Brochures / Solid_Phase_Peptide_Synthesis.pdf> QSAR Comb. Sci., 2007, 26, 1027-1035.Biopolymers, 2012, 98, 89-97.ACS Comb. Sci., 2013, 15, 229-234.

[0015] An object of the present invention is to provide a method for efficiently producing a highly pure peptide compound in high yield.

[0016] Non-Patent Documents 10 and 11 describe that in a condensation reaction in which the carboxyl group of an Fmoc-protected natural amino acid is condensed with the amino group of a natural amino acid supported on a CTC resin to form an amide bond, the use of acidic additives such as oxyma, HOBt, or HOAt results in a decrease in yield due to premature cleavage, whereas the yield can be improved by a condensation reaction using HBTU and DIPEA under basic conditions. However, the effect of suppressing premature cleavage is limited, and basic conditions can also cause racemization of amino acids, making these reaction conditions undesirable. In particular, there are no known reports on the problem of premature cleavage during peptide synthesis containing highly sterically hindered unnatural amino acids such as N-methylamino acids.

[0017] The present inventors attempted to identify amino acids that may undergo premature cleavage in solid-phase synthesis using CTC resin. Furthermore, when solid-phase synthesis using CTC resin was investigated for peptide synthesis containing highly sterically hindered amino acid residues, such as N-substituted amino acids, they found that in the step of condensing the C-terminal amino acid (sometimes referred to as the "first amino acid residue") supported on the solid-phase synthesis resin with the amino acid two residues from the C-terminus (sometimes simply referred to as the "second amino acid residue"), (i) a decrease in yield due to the elimination reaction of the first amino acid residue from the CTC resin, i.e., premature cleavage, and (ii) a decrease in purity due to the by-production of an over-extended product, in which the eliminated amino acid is incorporated in excess into the target amino acid sequence.

[0018] As described above, detachment of an amino acid residue or peptide residue supported on a solid-phase synthesis resin from a resin linker for solid-phase synthesis, more specifically, detachment of the first amino acid residue directly bonded to a solid-phase synthesis resin from a resin linker for solid-phase synthesis, can occur with a variety of amino acid residues. However, to date, no efficient method for synthesizing peptides that suppresses the above-mentioned problems and inhibits the production of by-products has been known. An objective of the present invention is to provide a method for producing high-purity peptide compounds in high yields using a peptide supported on a solid-phase synthesis resin as a starting material, which method is also applicable to the production of peptides containing unnatural amino acid residues.

[0019]

[0003] As a result of investigations aimed at solving the above problems, the present inventors discovered a method for directly supporting an oligopeptide on a resin in the solid-phase synthesis of peptide compounds containing highly sterically hindered unnatural amino acids. This method avoids the condensation step of the first and second amino acids in solid-phase synthesis, which is prone to premature cleavage. It was also confirmed that oligopeptides are less likely to be detached from the resin, and that premature cleavage is suppressed when an additional amino acid is elongated on oligopeptide residues supported on a solid-phase synthesis resin.

[0020] In a non-limiting specific aspect, the present invention includes the following: [1] A method for producing a peptide compound containing at least one N-substituted amino acid residue, a salt thereof, or a solvate thereof by a solid-phase method, characterized in that the peptide is supported on a solid-phase synthesis resin before the first elongation reaction in the solid-phase method. [2] A method for producing a peptide compound containing at least one N-substituted amino acid residue, a salt thereof, or a solvate thereof by a solid-phase method, comprising a step of supporting the peptide on a solid-phase synthesis resin. [3] The method of [1] or [2], wherein the peptide is an oligopeptide containing two or more amino acid residues. [4] The method of any of [1] to [3], wherein the peptide is a dipeptide or tripeptide. [5] The method of any of [1] to [4], wherein the C-terminal amino acid residue of the peptide and / or the amino acid residue adjacent to the C-terminal amino acid residue is an unnatural amino acid residue. [6] The method of any of [1] to [5], wherein the C-terminal amino acid residue of the peptide is an unnatural amino acid residue. [7] The method of [5] or [6], wherein the unnatural amino acid residue is an N-substituted amino acid residue. [8] The method of any of [1] to [7], wherein the C-terminal amino acid residue of the peptide is supported on a solid-phase synthesis resin via a carboxyl group bonded to the β- or γ-carbon atom of the amino group. [9] The method of any of [1] to [8], wherein the C-terminal amino acid residue of the peptide and / or the amino acid residue adjacent to the C-terminal amino acid residue has a bulky side chain.

[10] The method of [9], wherein the bulky side chain is an optionally substituted branched-chain alkyl group.

[11] The method of

[10] , wherein the branched-chain alkyl group is bonded to the α-carbon atom of the carboxyl group.

[12] The method of

[11] , wherein the branched-chain alkyl group has a branch at the β- or γ-carbon atom of the carboxyl group.

[13] The method of any of [1] to

[12] , wherein at least one N-substituted amino acid residue contained in the peptide compound is an unnatural N-substituted amino acid residue.

[14] The method according to any one of [1] to

[13] , wherein the peptide compound contains at least two N-substituted amino acid residues.

[15] The method according to any one of [1] to

[14] , wherein 30% or more of the total amino acid residues constituting the peptide compound are N-substituted amino acid residues.

[16] The method according to any one of [1] to

[15] , wherein the C-terminal amino acid residue of the peptide is aspartic acid, 2-aminobutanoic acid, glycine, alanine, valine, proline, tyrosine, or 2-aminoisobutyric acid, or an N-substituted or derivative thereof, and wherein the aspartic acid or the N-substituted or derivative thereof is supported on a resin for solid phase synthesis via the carboxyl group at the β-position of the amino group.

[17] The method according to any one of [1] to

[16] , wherein the C-terminal amino acid residue of the peptide is represented by the following formula (A): In the formula, L １ is a single bond or -CHM １ -, -CH ２ CHM １ -, -CHM １ CH ２ -, -(CH ２ ) ｎ S (CH ２ ) ｍ -, -(CH ２ ) ｎ S(O)(CH ２ ) ｍ - or - (CH ２ ) ｎ S (O) ２ (CH ２ ) ｍ -, where n and m are each independently 1 or 2; R １ is hydrogen, C １ -C ６ Alkyl, C ２ -C ６ Alkenyl, C ２ -C ６ Alkynyl, C １ -C ６ Alkoxy C １ -C ６ Alkyl, C ７ -C １４ aralkyl, or aminocarbonyl (wherein the amino is —NH ２ , Mono C １ -C ６ Alkylamino, DiC １ -C６ alkylamino, or 4- to 8-membered cyclic amino), each of which is selected from halogen, oxo, hydroxy, C １ -C ６ alkyl, 4- to 7-membered heterocyclyl, aminocarbonyl (wherein the amino is -NH ２ , Mono C １ -C ６ Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino), C １ -C ６ Alkylsulfonyl, and C １ -C ６ Alkoxy C １ -C ６ alkyl, or R １ is a peptide chain containing 1 to 4 amino acid residues, or R １ and P １ is R １ and the carbon atom to which P is bonded. １ together with the nitrogen atom to which R is attached to form a 4- to 7-membered saturated heterocyclic ring, or １ and Q １ together with the carbon atoms to which they are attached form a 3- to 8-membered alicyclic ring or a 4- to 7-membered saturated heterocyclic ring, or R １ and M １ is R １ and the carbon atom to which M is bonded. １ together with the carbon atom to which R is attached form a 3- to 8-membered alicyclic ring, １ and P １ forms a 4- to 7-membered saturated heterocyclic ring, １ is hydrogen or C １ -C ６ alkyl, and １ -C ６ Alkyl is substituted with halogen, hydroxy, C １ -C ６ Alkoxy, amino (the amino is —NH ２ , Mono C １ -C ６ Alkylamino, DiC１ -C ６ alkylamino, or 4- to 8-membered cyclic amino, each of which may be substituted with halogen), and aminocarbonyl (the amino is —NH ２ , Mono C １ -C ６ Alkylamino, DiC １ -C ６ R is optionally substituted with one or more groups independently selected from the group consisting of alkylamino, 4- to 8-membered cyclic amino, １ and Q １ Q forms a 3- to 8-membered alicyclic ring or a 4- to 7-membered saturated heterocyclic ring, １ is hydrogen or C １ -C ６ alkyl, R １ and M １ forms a 3- to 8-membered alicyclic ring, M １ is hydrogen, * represents a binding site with a resin for solid phase synthesis, and a wavy line represents a binding site with an adjacent amino acid residue.

[18] L １ is -CHM １ - and R １ is hydrogen, C １ -C ６ Alkyl, haloC １ -C ６ Alkyl, C ２ -C ６ Alkenyl, C ２ -C ６ Alkynyl, C １ -C ６ Alkoxy C １ -C ６ Alkyl (the C １ -C ６ Alkoxy C １ -C ６ Alkyl is hydroxy, or aminocarbonyl (wherein the amino is -NH ２ , Mono C １ -C ６ Alkylamino, DiC １ -C ６alkylamino, or 4- to 8-membered cyclic amino), C optionally substituted by one or more halogens ７ -C １４ aralkyl, or aminocarbonyl (wherein the amino is —NH ２ , Mono C １ -C ６ Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino, wherein the cyclic amino is selected from the group consisting of one or more halogens, one or more oxo, one or more C １ -C ６ alkyl, or 4- to 7-membered heterocyclyl), or R １ and M １ is R １ and the carbon atom to which M is bonded. １ together with the carbon atom to which R is attached to form a 3- to 8-membered alicyclic ring, or １ and P １ Is, P １ and the nitrogen atom to which R １ together with the carbon atom to which R is attached form a 4- to 7-membered saturated heterocyclic ring, １ and M １ forms a 3- to 8-membered alicyclic ring, M １ is hydrogen, and R １ and P １ forms a 4- to 7-membered saturated heterocyclic ring, １ is hydrogen or C １ -C ６ is alkyl, and Q １

[19] The method according to

[17] , wherein the C-terminal amino acid residue of the peptide is bAla, bMeAla, 2-ACHxC, 2-ACPnC, 3-CF3-bAla, Asp-mor, Asp-mor(26-bicyc), Asp-mor(SO2), Asp-NMe2, Asp-oxz, Asp-pip, Asp-pip(345-F6), Asp-pip(4-Me), Asp-pip-tBu, Asp-piz(oxe), Asp-pyrro, or Asp-pyrro (34-F4), Asp-pyrro(3-Me2), D-(Propargyl)Gly-(C#CH2), D-3-Abu, D-3-MeAbu, D-Gly(Allyl)-(C#CH2), D-Hph-(C#C H2), D-Leu-(C#CH2), D-MeAsp-pyrro, D-MeLeu-(C#CH2), D-Pic(2)-(C#CH2), D-Pro-(C#CH2), D-Ser(iPen)-(C#CH2), D-Ser(NtBu-Aca)-(C#CH2), EtAsp-pip, MeAsp-aze, MeAsp-mor, MeAsp-mor(26-bicyc), MeAsp-mor(SO2), MeAsp-NMe2 , MeAsp-oxz, MeAsp-pip, MeAsp-pip(345-F6), MeAsp-pip(3-F2), MeAsp-pip(4-F2), MeAsp-pip(4-Me), MeAsp-piz(ox

[17] The method according to

[17] , wherein the amino acid residue adjacent to the C-terminal amino acid residue of the peptide is represented by the following formula (B): MeAsp-pyrro, MeAsp-pyrro(34-F4), MeAsp-pyrro(3-Me2), nPrAsp-pip, MeGly, MeVal, Pro, Aib, Ala, Gly, Tyr(tBu), Val, D-MeAsp-NMe2, Glu-mor, Glu-pip, MeGlu-pip, Glu-NMe2, MeGlu-NMe2, or MeCys(AcOH)-NMe2.

[20] The method according to any of [1] to

[19] , wherein the amino acid residue adjacent to the C-terminal amino acid residue of the peptide is represented by the following formula (B): In the formula, L ２ is a single bond or -CH ２ - and R ２ is hydrogen, C １ -C ６ Alkyl, C２ -C ６ Alkynyl, C １ -C ６ Alkoxy C １ -C ６ Alkyl, C ３ -C ８ Cycloalkyl, C ３ -C ８ Cycloalkyl C １ -C ６ Alkyl, C ３ -C ８ Cycloalkoxy C １ -C ６ Alkyl, or C ７ -C １４ and aralkyl, each of which is selected from halogen, hydroxy, amino (wherein the amino is -NH ２ , protected amino, mono C １ -C ６ Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino, each of which may be substituted with halogen), aminocarbonyl (the amino is —NH ２ , protected amino, mono C １ -C ６ Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino), and C １ -C ６ alkylsulfonyl; or R ２ and P ２ is R ２ and the carbon atom to which P is bonded. ２ together with the nitrogen atom to which R is attached to form a 4- to 7-membered saturated heterocyclic ring, or ２ and Q ２ together with the carbon atoms to which they are attached form a 3- to 8-membered alicyclic ring or a 4- to 7-membered saturated heterocyclic ring, or R ２ and P ２ forms a 4- to 7-membered saturated heterocyclic ring, ２ is hydrogen or C １ -C６ alkyl, and the C １ -C ６ Alkyl is substituted with halogen, hydroxy, C １ -C ６ Alkoxy, amino (the amino is —NH ２ , Mono C １ -C ６ Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino, each of which may be substituted with halogen), and aminocarbonyl (the amino is —NH ２ , Mono C １ -C ６ Alkylamino, DiC １ -C ６ R is optionally substituted with one or more groups independently selected from the group consisting of alkylamino, 4- to 8-membered cyclic amino, ２ and Q ２ Q forms a 3- to 8-membered alicyclic ring or a 4- to 7-membered saturated heterocyclic ring, ２ is hydrogen or C １ -C ６ alkyl, * indicates the bonding site with the C-terminal amino acid residue, and the wavy line indicates the bonding site with the adjacent amino acid residue or the protecting group of the amino group.

[21] R ２ is C １ -C ６ Alkyl, haloC １ -C ６ Alkyl, hydroxy C １ -C ６ Alkyl, C １ -C ６ Alkylsulfonyl C １ -C ６ Alkyl, C ２ -C ６ alkynyl, C optionally substituted by one or more halogens １ -C ６ Alkoxy C １ -C ６ Alkyl, C ３ -C ８ Cycloalkyl, C ３ -C ８Cycloalkyl C １ -C ６ Alkyl, C ３ -C ８ Cycloalkoxy C １ -C ６ Alkyl, or C ７ -C １４ aralkyl, or R ２ and P ２ Is, P ２ and the nitrogen atom to which R ２ together with the carbon atom to which R is attached form a 4- to 7-membered saturated heterocyclic ring, ２ and P ２ forms a 4- to 7-membered saturated heterocyclic ring, ２ is hydrogen or C １ -C ６

[22] The method according to

[20] , wherein the amino acid residue adjacent to the C-terminal amino acid residue of the peptide is MeAla, MeLeu, MeCha, MeVal, MeAla(cPent), MeAla(cBu), MeAla(cPr), MeChg, MeGly(cPent), MeGly(cBu), MeGly(cPr), MeAbu, MeNva, MeNle, Val, Leu, MeNva(5-F2), MeHle, MeIle, MeSer(nPr), MeSer(cPr), MeHnl,

[21] The method according to

[21] , wherein the peptide is MeHnl(7-F2), MePRA, MeSer(Me), MeThr, MeSer(cBu), MeSer(Tfe), MeThr(Me), MeHse(Me), MeMet(O2), Ile, Nle, Chg, Ala(cBu), Gly(cPent), Hle, Nva, Phe, Hph, Gly, Aib, Lys(Boc), Ala, D-MeVal, Asn(Trt), Ser(tBu), or bAla(2-Me2).

[23] The method according to any one of [1] to

[22] , wherein the peptide is a dipeptide represented by the following formula (1): In the formula, L １ is a single bond or -CHM １ -, -CH ２ CHM １ -, -CHM １ CH ２ -, -(CH２ ) ｎ S (CH ２ ) ｍ -, -(CH ２ ) ｎ S(O)(CH ２ ) ｍ - or - (CH ２ ) ｎ S (O) ２ (CH ２ ) ｍ -, where n and m are each independently 1 or 2; R １ is hydrogen, C １ -C ６ Alkyl, C ２ -C ６ Alkenyl, C ２ -C ６ Alkynyl, C １ -C ６ Alkoxy C １ -C ６ Alkyl, C ７ -C １４ aralkyl, or aminocarbonyl (wherein the amino is —NH ２ , Mono C １ -C ６ Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino), each of which is selected from halogen, oxo, hydroxy, C １ -C ６ alkyl, 4- to 7-membered heterocyclyl, aminocarbonyl (wherein the amino is -NH ２ , Mono C １ -C ６ Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino) and C １ -C ６ alkylsulfonyl, or R １ is a peptide chain containing 1 to 4 amino acid residues, or R １ and P １ is R １ and the carbon atom to which P is bonded. １together with the nitrogen atom to which R is attached to form a 4- to 7-membered saturated heterocyclic ring, or １ and Q １ together with the carbon atoms to which they are attached form a 3- to 8-membered alicyclic ring or a 4- to 7-membered saturated heterocyclic ring, or R １ and M １ is R １ and the carbon atom to which M is bonded. １ together with the carbon atom to which R is attached form a 3- to 8-membered alicyclic ring, １ and P １ forms a 4- to 7-membered saturated heterocyclic ring, １ is hydrogen or C １ -C ６ alkyl, and １ -C ６ Alkyl is substituted with halogen, hydroxy, C １ -C ６ Alkoxy, amino (the amino is —NH ２ , Mono C １ -C ６ Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino, each of which may be substituted with halogen), and aminocarbonyl (the amino is —NH ２ , Mono C １ -C ６ Alkylamino, DiC １ -C ６ R is optionally substituted with one or more groups independently selected from the group consisting of alkylamino, 4- to 8-membered cyclic amino, １ and Q １ Q forms a 3- to 8-membered alicyclic ring or a 4- to 7-membered saturated heterocyclic ring, １ is hydrogen or C １ -C ６ alkyl, R １ and M １ forms a 3- to 8-membered alicyclic ring, M １ is hydrogen, and L ２ is a single bond or -CH ２ - and R ２is hydrogen, C １ -C ６ Alkyl, C ２ -C ６ Alkynyl, C １ -C ６ Alkoxy C １ -C ６ Alkyl, C ３ -C ８ Cycloalkyl, C ３ -C ８ Cycloalkyl C １ -C ６ Alkyl, C ３ -C ８ Cycloalkoxy C １ -C ６ Alkyl, or C ７ -C １４ and aralkyl, each of which is selected from halogen, hydroxy, amino (wherein the amino is -NH ２ , protected amino, mono C １ -C ６ Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino, each of which may be substituted with halogen), aminocarbonyl (the amino is —NH ２ , protected amino, mono C １ -C ６ Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino), and C １ -C ６ alkylsulfonyl; or R ２ and P ２ is R ２ and the carbon atom to which P is bonded. ２ together with the nitrogen atom to which R is attached to form a 4- to 7-membered saturated heterocyclic ring, or ２ and Q ２ together with the carbon atoms to which they are attached form a 3- to 8-membered alicyclic ring or a 4- to 7-membered saturated heterocyclic ring, or R ２ and P ２ forms a 4- to 7-membered saturated heterocyclic ring,２ is hydrogen or C １ -C ６ alkyl, and １ -C ６ Alkyl is substituted with halogen, hydroxy, C １ -C ６ Alkoxy, amino (the amino is —NH ２ , Mono C １ -C ６ Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino, each of which may be substituted with halogen), and aminocarbonyl (the amino is —NH ２ , Mono C １ -C ６ Alkylamino, DiC １ -C ６ R is optionally substituted with one or more groups independently selected from the group consisting of alkylamino, 4- to 8-membered cyclic amino, ２ and Q ２ Q forms a 3- to 8-membered alicyclic ring or a 4- to 7-membered saturated heterocyclic ring, ２ is hydrogen or C １ -C ６ alkyl, * represents a binding site with a resin for solid phase synthesis, PG is a protecting group for an amino group, provided that P １ and P ２ and (24) the method according to (23), wherein the peptide is a dipeptide represented by the following formula (2): In the formula, R １ is hydrogen, C １ -C ６ Alkyl, haloC １ -C ６ Alkyl, C ２ -C ６ Alkenyl, C ２ -C ６ Alkynyl, C １ -C ６ Alkoxy C １ -C ６ Alkyl (the C １ -C ６ Alkoxy C １ -C６ Alkyl is hydroxy, or aminocarbonyl (wherein the amino is -NH ２ , Mono C １ -C ６ Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino), C optionally substituted by one or more halogens ７ -C １４ aralkyl, or aminocarbonyl (wherein the amino is —NH ２ , Mono C １ -C ６ Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino, wherein the cyclic amino is selected from the group consisting of one or more halogens, one or more oxo, one or more C １ -C ６ alkyl, or 4- to 7-membered heterocyclyl), or R １ and M １ is R １ and the carbon atom to which M is bonded. １ together with the carbon atom to which R is attached to form a 3- to 8-membered alicyclic ring, or １ and P １ Is, P １ and the nitrogen atom to which R １ together with the carbon atom to which R is attached form a 4- to 7-membered saturated heterocyclic ring, １ and M １ forms a 3- to 8-membered alicyclic ring, M １ is hydrogen, and R １ and P １ forms a 4- to 7-membered saturated heterocyclic ring, １ is hydrogen or C １ -C ６ alkyl, R ２ is C １ -C ６ Alkyl, haloC １ -C ６ Alkyl, hydroxy C １ -C ６Alkyl, C １ -C ６ Alkylsulfonyl C １ -C ６ Alkyl, C ２ -C ６ alkynyl, C optionally substituted by one or more halogens １ -C ６ Alkoxy C １ -C ６ Alkyl, C ３ -C ８ Cycloalkyl, C ３ -C ８ Cycloalkyl C １ -C ６ Alkyl, C ３ -C ８ Cycloalkoxy C １ -C ６ Alkyl, or C ７ -C １４ aralkyl, or R ２ and P ２ Is, P ２ and the nitrogen atom to which R ２ together with the carbon atom to which R is attached form a 4- to 7-membered saturated heterocyclic ring, ２ and P ２ forms a 4- to 7-membered saturated heterocyclic ring, ２ is hydrogen or C １ -C ６ is alkyl, and Q ２ is hydrogen, * represents a binding site with a resin for solid phase synthesis, PG is a protecting group for an amino group, and １ and P ２and do not both become hydrogen.

[25] The method according to any one of [1] to

[24] , wherein the resin for solid phase synthesis is a resin that can be removed under mild acidic conditions.

[26] The method according to

[25] , wherein the mild acidic conditions are conditions under which protecting groups of the side chains of one or more amino acids contained in the peptide compound supported on the resin for solid phase synthesis are not removed.

[27] The method according to any one of

[25] or

[26] , wherein the mild acidic conditions include temperature conditions around room temperature.

[28] The method according to any one of

[25] to

[27] , wherein the mild conditions include conditions using a dilute solution of acid, and the dilute solution of acid is obtained by diluting an acid with a non-acidic solvent.

[29] The method according to

[25] to

[28] , wherein the mild acidic conditions are acidic conditions of pH 2 or higher.

[30] The method according to

[28] or

[29] , wherein the acid has a pKa in water of -1 or more, 1 or more, 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, 10 or more, 11 or more, or 12 or more.

[31] The method according to

[30] , wherein the acid is TFA, 2,2,2-trifluoroethanol, 1,1,1,3,3,3-hexafluoroisopropyl alcohol, trichloroacetic acid, acetic acid, formic acid, oxalic acid, or a mixture thereof.

[32] The method according to any one of

[29] to

[31] , wherein the volume percentage of the acid in the dilute solution is 60% or less, 50% or less, 40% or less, 30% or less, 20% or less, 10% or less, 5% or less, 4% or less, 3% or less, 2% or less, or 1% or less.

[33] The method according to any one of

[29] to

[32] , wherein the non-acidic solvent is DCM, dichloroethane, water, 2-MeTHF, or a mixed solvent thereof.

[34] The method according to any one of

[26] to

[33] , wherein the protecting group is selected from the group consisting of Boc, Trt, THP, and tBu.

[35] The method according to any one of

[26] to

[34] , wherein the amino acid having a protecting group at the side chain is Tyr(tBu), Ser(tBu), Thr(tBu), Asp(tBu), Glu(tBu), Trp(Boc), Lys(Boc), His(Boc), Ser(Trt), Thr(Trt), Trp(Trt), Lys(Trt), His(Trt), Asn(Trt), Gln(Trt), Ser(THP), Thr(THP), or N-alkylated versions thereof.

[36] The method according to any one of [1] to

[35] , wherein the resin for solid phase synthesis is CTC resin, Wang resin, SASRIN resin, Trt resin, Mtt resin, Mmt resin, or Sieber resin.

[37] The method according to

[36] , wherein the resin for solid phase synthesis is CTC resin or Sieber resin.

[38] The method according to any one of [1] and [3] to

[37] , comprising a step of supporting a peptide on a resin for solid phase synthesis.

[39] The method according to any one of [1] to

[38] , further comprising a step of elongating the peptide by one or more amino acid residues.

[40] A method for producing a cyclic peptide, a salt thereof, or a solvate thereof, comprising the steps of: obtaining a peptide compound containing at least one N-substituted amino acid residue, a salt thereof, or a solvate thereof according to the method of any of [1] to

[39] , removing the solid-phase synthesis resin, and cyclizing the C-terminal group and the N-terminal group of the peptide compound, salt thereof, or solvate thereof to form a cyclic moiety.

[41] A method for producing a peptide compound containing at least one N-substituted amino acid residue, a salt thereof, or a solvate thereof by a solid-phase synthesis method, characterized in that the peptide is supported on a solid-phase synthesis resin before the first elongation reaction, thereby improving the recovery rate of the peptide compound compared to when amino acids are elongated one residue at a time.

[42] A method for producing a peptide compound containing at least one N-substituted amino acid residue, a salt thereof, or a solvate thereof by a solid-phase synthesis method, characterized in that the peptide is supported on a solid-phase synthesis resin before the first elongation reaction, thereby suppressing the generation of impurities compared to when amino acids are elongated one residue at a time.

[43] A method for producing a peptide compound containing at least one N-substituted amino acid residue, a salt thereof, or a solvate thereof by a solid-phase method, which method is characterized in that the peptide is supported on a resin for solid-phase synthesis before the first elongation reaction, thereby suppressing premature cleavage compared to when amino acids are elongated one residue at a time.

[0021] The present invention provides a useful method that can be applied to the production of peptide compounds of any sequence containing any type and number of amino acid residues, and that can produce peptide compounds in high yield and high purity. The present invention not only improves yield by suppressing premature cleavage, but also improves purity by avoiding the by-production of over-elongated peptides, thereby dramatically improving the purification efficiency of the target peptide compound and greatly improving the productivity of solid-phase peptide synthesis.

[0022] (Abbreviations) The abbreviations used in this specification are listed below. AA: Ammonium acetate, Al: Allyl, Alloc: Allyloxycarbonyl, Boc: t-butoxycarbonyl, Cbz: Benzyloxycarbonyl, COMU: (1-cyano-2-ethoxy-2-oxoethylideneaminooxy)dimethylaminomorpholinocarbenium hexafluorophosphate, DBU: 1,8-diazabicyclo[5.4.0]-7-undecene, DCM: Dichloromethane, DIC: N,N'-diisopropylcarbodiimide, DIPEA: N,N-diisopropylethylamine, DMF: N,N-dimethylformamide, DMSO: Dimethyl sulfoxide, EDCI: 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, FA: Formic acid, Fmoc: 9-fluorenylmethyloxycarbonyl, NMP: N-methyl-2-pyrrolidone HATU: O-(7-aza-1H-benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate HBTU: O-(1H-benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate HFIP: 1,1,1,3,3,3-hexafluoroisopropyl alcohol HOAt: 1-hydroxy-7-azabenzotriazole HOBt: 1-hydroxybenzotriazole oxyma: ethyl cyano(hydroxyimino)acetate TBME: t-butyl methyl ether Teoc: 2-(trimethylsilyl)ethoxycarbonyl TFA: trifluoroacetic acid TFE: 2,2,2-trifluoroethanol THF: tetrahydrofuran Trt: triphenylmethyl

[0023] The relationship between the amino acid abbreviations used herein and their structures is shown below. Note that in the table below, each amino acid is listed in a form in which the amino group is protected with an Fmoc group, but the relationship between the abbreviations of each amino acid and its residue with a free amino group after the Fmoc group has been removed and their structures can also be understood from the table below. Specifically, for example, it will be obvious to those skilled in the art that MeAsp-pip is an amino acid having the following structure obtained by removing the Fmoc group from Fmoc-MeAsp-pip in the table below, and the structure of this amino acid residue, MeAsp-pip, will also be obvious to those skilled in the art.

[0024] (Definition of Functional Groups, etc.) In this specification, examples of the "halogen atom" include F, Cl, Br and I.

[0025] As used herein, "alkyl" refers to a monovalent group derived from an aliphatic hydrocarbon by removing any one hydrogen atom, and does not contain heteroatoms (atoms other than carbon and hydrogen atoms) or unsaturated carbon-carbon bonds in the skeleton, but has a subset of hydrocarbyl or hydrocarbon group structures containing hydrogen and carbon atoms. Alkyl includes not only linear but also branched chain alkyls. Specific examples of alkyl include alkyls having 1 to 20 carbon atoms (C １ -C ２０ , hereinafter referred to as “C ｐ -C ｑ " means that the number of carbon atoms is p to q), and preferably C １ -C １０ Alkyl, more preferably C １ -C ６Specific examples of the alkyl include methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, t-butyl, isobutyl (2-methylpropyl), n-pentyl, s-pentyl (1-methylbutyl), t-pentyl (1,1-dimethylpropyl), neopentyl (2,2-dimethylpropyl), isopentyl (3-methylbutyl), 3-pentyl (1-ethylpropyl), 1,2-dimethylpropyl, 2-methylbutyl, n-hexyl, 1,1,2-trimethylpropyl, 1,2,2-trimethylpropyl, 1,1,2,2-tetramethylpropyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, 3,3-dimethylbutyl, 1-ethylbutyl, and 2-ethylbutyl.

[0026] As used herein, "alkenyl" refers to an alkyl group having at least one double bond (two adjacent SP ２ It is a monovalent group having 1 carbon atom. Depending on the configuration of the double bond and the substituents (if any), the geometry of the double bond can be in the Entgegen (E) or Zusammen (Z), cis or trans configuration. Alkenyl includes not only straight chains but also branched chains. C is preferred as alkenyl. ２ -C １０ alkenyl, more preferably C ２ -C ６ Examples include alkenyl, specifically, for example, vinyl, allyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl (including cis and trans), 3-butenyl, pentenyl, 3-methyl-2-butenyl, hexenyl, and the like.

[0027] As used herein, "alkynyl" refers to a monovalent group having at least one triple bond (two adjacent SP carbon atoms). Alkynyl includes not only straight chain but also branched chain. C ２ -C １０ Alkynyl, more preferably C ２ -C ６Specific examples include alkynyl, such as ethynyl, 1-propynyl, propargyl, 3-butynyl, pentynyl, hexynyl, 3-phenyl-2-propynyl, 3-(2'-fluorophenyl)-2-propynyl, 2-hydroxy-2-propynyl, 3-(3-fluorophenyl)-2-propynyl, and 3-methyl-(5-phenyl)-4-pentynyl.

[0028] As used herein, the term "cycloalkyl" refers to a saturated or partially saturated cyclic monovalent aliphatic hydrocarbon group, including monocyclic, bicyclic, and spirocyclic rings. ３ -C ８ Examples of cycloalkyl include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, bicyclo[2.2.1]heptyl, spiro[3.3]heptyl, and the like.

[0029] As used herein, "aryl" refers to a monovalent aromatic hydrocarbon ring, preferably C ６ -C １０ Specific examples of the aryl include phenyl and naphthyl (for example, 1-naphthyl and 2-naphthyl).

[0030] As used herein, the term "heterocyclyl" refers to a non-aromatic cyclic monovalent group containing 1 to 5 heteroatoms in addition to carbon atoms. The heterocyclyl may have a double and / or triple bond in the ring, and a carbon atom in the ring may be oxidized to form a carbonyl. The heterocyclyl may be a monocyclic or fused ring. The number of atoms constituting the ring is preferably 4 to 10 (4- to 10-membered heterocyclyl), more preferably 4 to 7 (4- to 7-membered heterocyclyl). Specific examples of heterocyclyl include azetidinyl, oxiranyl, oxetanyl, azetidinyl, dihydrofuryl, tetrahydrofuryl, dihydropyranyl, tetrahydropyranyl, tetrahydropyridyl, tetrahydropyrimidyl, morpholinyl, thiomorpholinyl, pyrrolidinyl, piperidinyl, piperazinyl, pyrazolidinyl, imidazolinyl, imidazolidinyl, oxazolidinyl, isoxazolidinyl, thiazolidinyl, and isothiazolidinyl. nyl, 1,2-thiazinane, thiadiazolidinyl, azetidinyl, oxazolidonyl, benzodioxanyl, benzoxazolyl, dioxolanyl, dioxanyl, tetrahydropyrrolo[1,2-c]imidazole, thietanyl, 3,6-diazabicyclo[3.1.1]heptanyl, 2,5-diazabicyclo[2.2.1]heptanyl, 3-oxa-8-azabicyclo[3.2.1]octanyl, sultam, 2-oxaspiro[3.3]heptyl, and the like.

[0031] As used herein, the term "protected heterocyclyl" refers to a group in which one or more functional groups included in the above-defined "heterocyclyl," such as an amino group, are protected with any protecting group, and preferably includes a protected 4- to 7-membered heterocyclyl. Specific examples of the protecting group include Boc, Fmoc, Cbz, Troc, and Alloc, and specific examples of the protected heterocyclyl include Boc-protected azetidine.

[0032] As used herein, "heterocycloalkylidene" refers to a divalent group resulting from the removal of two hydrogen atoms from one carbon atom of the above-defined "heterocyclyl," in which the free valence becomes part of a double bond. Preferred examples of heterocycloalkylidene include 4- to 7-membered heterocycloalkylidenes, and specific examples include tetrahydropyran-4-ylidene and azetidin-3-ylidene.

[0033] As used herein, the term "protected heterocycloalkylidene" refers to a group in which one or more functional groups included in the above-defined "heterocycloalkylidene," such as an amino group, are protected with any protecting group, and preferably includes a protected 4- to 7-membered heterocycloalkylidene. Specific examples of the protecting group include Boc, Fmoc, Cbz, Troc, and Alloc, and specific examples of the protected heterocyclyl include Boc-protected azetidin-3-ylidene.

[0034] As used herein, "heteroaryl" refers to an aromatic, cyclic, monovalent group containing 1 to 5 heteroatoms in addition to carbon atoms. The ring may be a monocyclic ring or a condensed ring with another ring, and may be partially saturated. The number of atoms constituting the ring is preferably 5 to 10 (5- to 10-membered heteroaryl), and more preferably 5 to 7 (5- to 7-membered heteroaryl). Specific examples of heteroaryl include furyl, thienyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, isothiazolyl, oxazolyl, isoxazolyl, oxadiazolyl, thiadiazolyl, triazolyl, tetrazolyl, pyridyl, pyrimidyl, pyridazinyl, pyrazinyl, triazinyl, benzofuranyl, benzothienyl, benzothiadiazolyl, benzothiazolyl, benzoxazolyl, benzoxadiazolyl, benzimidazolyl, indolyl, isoindolyl, indazolyl, quinolyl, isoquinolyl, cinnolinyl, quinazolinyl, quinoxalinyl, benzodioxolyl, indolizinyl, and imidazopyridyl.

[0035] As used herein, "alkoxy" refers to an oxy group to which the above-defined "alkyl" is bonded, and preferably C１ -C ６ Specific examples of the alkoxy include methoxy, ethoxy, 1-propoxy, 2-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy, pentyloxy, and 3-methylbutoxy.

[0036] As used herein, "alkenyloxy" refers to an oxy group having the above-defined "alkenyl" bonded thereto, and preferably C ２ -C ６ Specific examples of alkenyloxy include vinyloxy, allyloxy, 1-propenyloxy, 2-propenyloxy, 1-butenyloxy, 2-butenyloxy (including cis and trans), 3-butenyloxy, pentenyloxy, and hexenyloxy.

[0037] As used herein, "cycloalkoxy" refers to an oxy group to which the above-defined "cycloalkyl" is bonded, and preferably C ３ -C ８ Specific examples of cycloalkoxy include cyclopropoxy, cyclobutoxy, cyclopentyloxy, etc.

[0038] As used herein, "aryloxy" refers to an oxy group to which the above-defined "aryl" is bonded, and preferably C ６ -C １０ Specific examples of the aryloxy include phenoxy, 1-naphthyloxy, and 2-naphthyloxy.

[0039] In the present specification, "amino" means, in a narrow sense, -NH ２ and broadly, -NRR', where R and R' are independently selected from hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl, or heteroaryl, or R and R' together with the nitrogen atom to which they are attached form a ring. ２ , Mono C １ -C６ Alkylamino, DiC １ -C ６ Examples thereof include alkylamino and 4- to 8-membered cyclic amino.

[0040] As used herein, the term "monoalkylamino" refers to a group in which R is hydrogen and R' is an "alkyl" as defined above, among the "amino" groups defined above, and preferably monoC １ -C ６ Specific examples of monoalkylamino include methylamino, ethylamino, n-propylamino, i-propylamino, n-butylamino, s-butylamino, and t-butylamino.

[0041] As used herein, "dialkylamino" refers to a group in which R and R' are independently "alkyl" as defined above, among the "amino" groups defined above, and preferably diC １ -C ６ Specific examples of dialkylamino include dimethylamino and diethylamino.

[0042] As used herein, "cyclic amino" refers to the above-defined "amino" in which R and R' form a ring together with the nitrogen atom to which they are attached, and preferably includes 4- to 8-membered cyclic amino. Specific examples of cyclic amino include 1-azetidyl, 1-pyrrolidyl, 1-piperidyl, 1-piperazyl, 4-morpholinyl, 3-oxazolidyl, 1,1-dioxidethiomorpholinyl-4-yl, 3-oxa-8-azabicyclo[3.2.1]octan-8-yl, and the like.

[0043] As used herein, the term "protected amino" refers to an amino group protected with any protecting group. Specific examples of the protected amino include amino protected with a protecting group such as Boc, Fmoc, Cbz, Troc, Alloc, or Trt.

[0044] As used herein, "aminocarbonyl" refers to a carbonyl group having the above-defined "amino" bonded thereto, and preferably -CONH ２ , Mono C１ -C ６ Alkylaminocarbonyl, diC １ -C ６ Examples of the aminocarbonyl include alkylaminocarbonyl and 4- to 8-membered cyclic aminocarbonyl. ２ , dimethylaminocarbonyl, 1-azetidinylcarbonyl, 1-pyrrolidinylcarbonyl, 1-piperidinylcarbonyl, 1-piperazinylcarbonyl, 4-morpholinylcarbonyl, 3-oxazolidinylcarbonyl, 1,1-dioxidethiomorpholinyl-4-ylcarbonyl, 3-oxa-8-azabicyclo[3.2.1]octan-8-ylcarbonyl, and the like.

[0045] As used herein, "alkenyloxycarbonyl" refers to a carbonyl group to which the above-defined "alkenyloxy" is bonded, and preferably C ２ -C ６ Specific examples of the alkenyloxycarbonyl include vinyloxycarbonyl, allyloxycarbonyl, 1-propenyloxycarbonyl, 2-propenyloxycarbonyl, 1-butenyloxycarbonyl, 2-butenyloxycarbonyl (including cis and trans), 3-butenyloxycarbonyl, pentenyloxycarbonyl, and hexenyloxycarbonyl.

[0046] As used herein, "alkylsulfonyl" refers to a sulfonyl group having an "alkyl" as defined above bonded thereto, and preferably C １ -C ６ Specific examples of alkylsulfonyl include methylsulfonyl.

[0047] The term "hydroxyalkyl" as used herein means a group in which one or more hydrogen atoms of the "alkyl" defined above are replaced with hydroxyl groups, and includes hydroxy C １ -C ６Alkyl is preferred. Specific examples of hydroxyalkyl include hydroxymethyl, 1-hydroxyethyl, 2-hydroxyethyl, 2-hydroxy-2-methylpropyl, and 5-hydroxypentyl.

[0048] As used herein, "haloalkyl" refers to a group in which one or more hydrogen atoms of the "alkyl" defined above are substituted with halogen atoms, and includes haloC １ -C ６ Alkyl is preferred, C １ -C ６ Fluoroalkyl is more preferred. Specific examples of haloalkyl include difluoromethyl, trifluoromethyl, 2,2-difluoroethyl, 2,2,2-trifluoroethyl, 3,3-difluoropropyl, 4,4-difluorobutyl, and 5,5-difluoropentyl.

[0049] As used herein, "cyanoalkyl" refers to a group in which one or more hydrogen atoms of the "alkyl" defined above are substituted with cyano, and includes cyanoC １ -C ６ Alkyl is preferred. Specific examples of cyanoalkyl include cyanomethyl and 2-cyanoethyl.

[0050] The term "aminoalkyl" as used herein means a group in which one or more hydrogen atoms of an "alkyl" as defined above are substituted with an "amino" as defined above, and an amino group １ -C ６ Alkyl is preferred. Specific examples of aminoalkyl include 1-pyridylmethyl, 2-(1-piperidyl)ethyl, 3-(1-piperidyl)propyl, and 4-aminobutyl.

[0051] As used herein, "carboxyalkyl" refers to a group in which one or more hydrogen atoms of the "alkyl" defined above are substituted with carboxy, and includes carboxy C １ -C ６ Alkyl is preferred. Specific examples of carboxyalkyl include carboxymethyl.

[0052] As used herein, "alkenyloxycarbonylalkyl" refers to a group in which one or more hydrogen atoms of an "alkyl" defined above are substituted with an "alkenyloxycarbonyl" defined above, and ２ -C ６ Alkenyloxycarbonyl C １ -C ６ Alkyl is preferred, C ２ -C ６ Alkenyloxycarbonyl C １ -C ２ Alkyl is more preferred. Specific examples of alkenyloxycarbonylalkyl include allyloxycarbonylmethyl and 2-(allyloxycarbonyl)ethyl.

[0053] As used herein, "alkoxyalkyl" refers to a group in which one or more hydrogen atoms of an "alkyl" defined above are substituted with an "alkoxy" defined above, and １ -C ６ Alkoxy C １ -C ６ Alkyl is preferred, C １ -C ６ Alkoxy C １ -C ２ Alkyl is more preferred. Specific examples of alkoxyalkyl include methoxymethyl, ethoxymethyl, 1-propoxymethyl, 2-propoxymethyl, n-butoxymethyl, i-butoxymethyl, s-butoxymethyl, t-butoxymethyl, pentyloxymethyl, 3-methylbutoxymethyl, 1-methoxyethyl, 2-methoxyethyl, and 2-ethoxyethyl.

[0054] As used herein, "cycloalkylalkyl" refers to a group in which one or more hydrogen atoms of an "alkyl" defined above are substituted with a "cycloalkyl" defined above, and C ３ -C ８ Cycloalkyl C １ -C ６ Alkyl is preferred, C ３ -C ６ Cycloalkyl C １ -C ２Alkyl is more preferred. Specific examples of cycloalkylalkyl include cyclopropylmethyl, cyclobutylmethyl, cyclopentylmethyl, and cyclohexylmethyl.

[0055] As used herein, "cycloalkoxyalkyl" refers to a group in which one or more hydrogen atoms of an "alkyl" defined above are substituted with a "cycloalkoxy" defined above, and C ３ -C ８ Cycloalkoxy C １ -C ６ Alkyl is preferred, C ３ -C ６ Cycloalkoxy C １ -C ２ Alkyl is more preferred. Specific examples of cycloalkoxyalkyl include cyclopropoxymethyl and cyclobutoxymethyl.

[0056] As used herein, "heterocyclylalkyl" refers to a group in which one or more hydrogen atoms of an "alkyl" defined above are replaced by a "heterocyclyl" defined above, and includes 4- to 7-membered heterocyclyl C １ -C ６ Alkyl is preferred, and 4- to 7-membered heterocyclyl C １ -C ２ Specific examples of heterocyclylalkyl include 2-(tetrahydro-2H-pyran-4-yl)ethyl and 2-(azetidin-3-yl)ethyl.

[0057] As used herein, "alkylsulfonylalkyl" refers to a group in which one or more hydrogen atoms of an "alkyl" defined above are substituted with an "alkylsulfonyl" defined above, and １ -C ６ Alkylsulfonyl C １ -C ６ Alkyl is preferred, C １ -C ６ Alkylsulfonyl C １ -C ２Alkyl is more preferred. Specific examples of alkylsulfonylalkyl include methylsulfonylmethyl and 2-(methylsulfonyl)ethyl.

[0058] As used herein, "aminocarbonylalkyl" refers to a group in which one or more hydrogen atoms of an "alkyl" defined above are substituted with an "aminocarbonyl" defined above, and an aminocarbonyl C １ -C ６ Alkyl is preferred, and aminocarbonyl C １ -C ４ Specific examples of aminocarbonylalkyl include methylaminocarbonylmethyl, dimethylaminocarbonylmethyl, t-butylaminocarbonylmethyl, 1-azetidinylcarbonylmethyl, 1-pyrrolidinylcarbonylmethyl, 1-piperidinylcarbonylmethyl, 4-morpholinylcarbonylmethyl, 2-(methylaminocarbonyl)ethyl, 2-(dimethylaminocarbonyl)ethyl, 2-(1-azetidinylcarbonyl)ethyl, 2-(1-pyrrolidinylcarbonyl)ethyl, 2-(4-morpholinylcarbonyl)ethyl, 3-(dimethylaminocarbonyl)propyl, and 4-(dimethylaminocarbonyl)butyl.

[0059] As used herein, "aryloxyalkyl" refers to a group in which one or more hydrogen atoms of an "alkyl" defined above are substituted with an "aryloxy" defined above, and ６ -C １０ Aryloxy C １ -C ６ Alkyl is preferred, C ６ -C １０ Aryloxy C １ -C ２ Alkyl is more preferred. Specific examples of aryloxyalkyl include phenoxymethyl and 2-phenoxyethyl.

[0060] As used herein, "aralkyl (arylalkyl)" refers to a group in which at least one hydrogen atom of an "alkyl" as defined above is substituted with an "aryl" as defined above, and C ７ -C１４ Aralkyl is preferred, C ７ -C １０ Aralkyl is more preferred. Specific examples of aralkyl include benzyl, phenethyl, and 3-phenylpropyl.

[0061] The term "aralkoxy" as used herein means an oxy group to which the above-defined "aralkyl" is bonded, and C ７ -C １４ Aralkoxy is preferred, C ７ -C １０ Aralkoxy is more preferred. Specific examples of aralkoxy include benzyloxy, phenethyloxy, and 3-phenylpropoxy.

[0062] As used herein, "aralkoxyalkyl" refers to a group in which one or more hydrogen atoms of an "alkyl" defined above are substituted with an "aralkoxy" defined above, and C ７ -C １４ Aralkoxy C １ -C ６ Alkyl is preferred, C ７ -C １４ Aralkoxy C １ -C ２ Alkyl is more preferred. Specific examples of aralkoxyalkyl include benzyloxymethyl and 1-(benzyloxy)ethyl.

[0063] As used herein, the term "heteroarylalkyl" refers to a group in which at least one hydrogen atom of an "alkyl" as defined above is substituted with a "heteroaryl" as defined above, and includes 5- to 10-membered heteroaryl C １ -C ６ Alkyl is preferred, and 5- to 10-membered heteroaryl C １ -C ２Specific examples of heteroarylalkyl include 3-thienylmethyl, 4-thiazolylmethyl, 2-pyridylmethyl, 3-pyridylmethyl, 4-pyridylmethyl, 2-(2-pyridyl)ethyl, 2-(3-pyridyl)ethyl, 2-(4-pyridyl)ethyl, 2-(6-quinolyl)ethyl, 2-(7-quinolyl)ethyl, 2-(6-indolyl)ethyl, 2-(5-indolyl)ethyl, and 2-(5-benzofuranyl)ethyl.

[0064] As used herein, "heteroarylalkoxy" refers to an oxy group to which the above-defined "heteroarylalkyl" is bonded, and is a 5- to 10-membered heteroaryl C １ -C ６ Alkoxy is preferred, and 5- to 10-membered heteroaryl C １ -C ２ Alkoxy is more preferred. Specific examples of heteroarylalkoxy include 3-thienylmethoxy and 3-pyridylmethoxy.

[0065] As used herein, "heteroarylalkoxyalkyl" refers to a group in which one or more hydrogen atoms of an "alkyl" defined above are substituted with a "heteroarylalkoxy" defined above, and includes 5- to 10-membered heteroaryl C １ -C ６ Alkoxy C １ -C ６ Alkyl is preferred, and 5- to 10-membered heteroaryl C １ -C ２ Alkoxy C １ -C ２ Alkyl is more preferred. Specific examples of heteroarylalkoxyalkyl include 3-pyridylmethoxymethyl.

[0066] As used herein, "heterocycloalkylidenealkyl" refers to a group in which one or more hydrogen atoms of the "alkyl" defined above are replaced by the "heterocycloalkylidene" defined above, and includes 4- to 7-membered heterocycloalkylidene C １ -C ６ Alkyl is preferred, and 4- to 7-membered heterocycloalkylidene C １ -C２ Specific examples of heteroarylalkoxyalkyl include tetrahydro-4H-pyran-4-ylidenemethyl and azetidin-3-ylidenemethyl.

[0067] As used herein, "alkoxyalkenyl" refers to a group in which one or more hydrogen atoms of an "alkenyl" defined above are substituted with an "alkoxy" defined above, and １ -C ６ Alkoxy C ２ -C ６ Alkenyl is preferred. Specific examples of alkoxyalkenyl include (E)-4-methoxybut-2-en-1-yl.

[0068] As used herein, "aminocarbonylalkenyl" refers to a group in which one or more hydrogen atoms of the "alkenyl" defined above are substituted with the "aminocarbonyl" defined above, and ２ -C ６ Alkenyl is preferred. Specific examples of aminocarbonylalkenyl include (E)-3-(dimethylaminocarbonylcarbonyl)-prop-2-en-1-yl.

[0069] As used herein, "haloalkoxy" refers to a group in which one or more hydrogen atoms of the "alkoxy" defined above are substituted with halogen atoms, and haloC １ -C ６ Alkoxy is preferred. Specific examples of haloalkoxy include difluoromethoxy, trifluoromethoxy, 2,2-difluoroethoxy, and 2,2,2-trifluoroethoxy.

[0070] The term "alkylene" as used herein means a divalent group derived from the above-mentioned "alkyl" by further removing one optional hydrogen atom, and C ４ -C ８ Alkylene is preferred. Specific examples of alkylene include —CH ２ -, -(CH ２ ) ２ -, -(CH ２ ) ３ -, -CH(CH３ ) CH ２ -, -C(CH ３ ) ２ -, -(CH ２ ) ４ -, -CH(CH ３ ) CH ２ CH ２ -, -C(CH ３ ) ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ -, -CH ２ C(CH ３ ) ２ -, -CH ２ CH ２ CH (CH ３ ) -, -(CH ２ ) ５ -, -(CH ２ ) ６ -, -(CH ２ ) ７ -, -(CH ２ ) ８ - and others.

[0071] As used herein, "alicyclic ring" refers to a non-aromatic hydrocarbon ring. The alicyclic ring may have an unsaturated bond within the ring, or may be a polycyclic ring having two or more rings. Furthermore, the carbon atoms constituting the ring may be oxidized to form a carbonyl. Preferred examples of the alicyclic ring include 3- to 8-membered alicyclic rings, and specific examples include a cyclopropane ring, a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, a cycloheptane ring, a cyclooctane ring, and a bicyclo[2.2.1]heptane ring.

[0072] As used herein, the term "saturated heterocycle" refers to a non-aromatic heterocycle containing 1 to 5 heteroatoms in addition to carbon atoms and containing no double and / or triple bonds within the ring. The saturated heterocycle may be a monocycle or may form a condensed ring with another ring, for example, an aromatic ring such as a benzene ring. Preferred examples of the saturated heterocycle include 4- to 7-membered saturated heterocycles, such as an azetidine ring, an oxetane ring, a tetrahydrofuran ring, a tetrahydropyran ring, a morpholine ring, a thiomorpholine ring, a pyrrolidine ring, a 4-oxopyrrolidine ring, a piperidine ring, a 4-oxopiperidine ring, a piperazine ring, a pyrazolidine ring, an imidazolidine ring, an oxazolidine ring, an isoxazolidine ring, a thiazolidine ring, an isothiazolidine ring, a thiadiazolidine ring, an oxazolidone ring, a dioxolane ring, a dioxane ring, a thietane ring, an octahydroindole ring, and an indoline ring.

[0073] As used herein, the term "peptide chain" refers to a peptide chain in which 1, 2, 3, 4, or more natural amino acids and / or unnatural amino acids are linked by amide bonds and / or ester bonds. The peptide chain is preferably a peptide chain containing 1 to 4 amino acid residues, and more preferably a peptide chain consisting of 1 to 4 amino acid residues.

[0074] As used herein, the term "amino-protecting group" includes carbamate-type protecting groups, amide-type protecting groups, arylsulfonamide-type protecting groups, alkylamine-type protecting groups, imide-type protecting groups, and the like. Specific examples include an Fmoc group, a Boc group, an Alloc group, a Cbz group, a Teoc group, a trifluoroacetyl group, a pentafluoropropionyl group, a phthaloyl group, a benzenesulfonyl group, a tosyl group, a nosyl group, a dinitronosyl group, a t-Bu group, a trityl group, a cumyl group, a benzylidene group, a 4-methoxybenzylidene group, a diphenylmethylidene group, and the like.

[0075] As used herein, the term "carboxyl-protecting group" includes alkyl ester-type protecting groups, benzyl ester-type protecting groups, substituted alkyl ester-type protecting groups, etc. Specific examples of carboxyl-protecting groups include methyl, ethyl, t-Bu, benzyl, trityl, cumyl, methoxytrityl, 2-(trimethylsilyl)ethyl, 2,2,2-trichloroethyl, and allyl.

[0076] As used herein, "hydroxy-protecting groups" include alkyl ether-type protecting groups, aralkyl ether-type protecting groups, silyl ether-type protecting groups, carbonate-type protecting groups, etc. Specific examples of hydroxy-protecting groups include a methoxymethyl group, a benzyloxymethyl group, a tetrahydropyranyl group, a tert-butyl group, an allyl group, a 2,2,2-trichloroethyl group, a benzyl group, a 4-methoxybenzyl group, a trimethylsilyl group, a triethylsilyl group, a triisopropylsilyl group, a t-butyldimethylsilyl group, a t-butyldiphenylsilyl group, a methoxycarbonyl group, a 9-fluorenylmethoxycarbonyl group, and a 2,2,2-trichloroethoxycarbonyl group.

[0077] As used herein, the term "optionally substituted" means that a group may be substituted with any substituent.

[0078] As used herein, the term "optionally protected" means that a group may be protected by any protecting group.

[0079] As used herein, "one or more" means one or more than one. When "one or more" is used in the context of substituents on a group, the term means a number from one to the maximum number of substituents permitted by that group. Specific examples of "one or more" include 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, and / or more.

[0080] The compound of the present invention can be a salt thereof, preferably a chemically or pharmaceutically acceptable salt thereof. The compound of the present invention or a salt thereof can also be a solvate thereof, preferably a chemically or pharmaceutically acceptable solvate thereof. Salts of the compound of the present invention include, for example, hydrochloride; hydrobromide; hydroiodide; phosphate; phosphonate; sulfate; sulfonate such as methanesulfonate and p-toluenesulfonate; carboxylate such as acetate, citrate, malate, tartrate, succinate, and salicylate; alkali metal salts such as sodium salt and potassium salt; alkaline earth metal salts such as magnesium salt and calcium salt; and ammonium salts such as ammonium salt, alkylammonium salt, dialkylammonium salt, trialkylammonium salt, and tetraalkylammonium salt. These salts can be produced, for example, by contacting the compound with an acid or base that can be used in the production of pharmaceuticals. In the present invention, a solvate of a compound refers to a compound that forms a molecular group together with a solvent, and is not particularly limited as long as it is a solvate formed with a solvent that is acceptable for ingestion accompanying the administration of a pharmaceutical. When the solvent is water, it is called a hydrate. As a solvate of the compound of the present invention, a hydrate is preferred, and specific examples of such hydrates include mono- to decahydrates, preferably mono- to pentahydrates, and more preferably mono- to trihydrates. The solvates of the compound of the present invention include not only solvates with a single solvent such as water, alcohols (e.g., methanol, ethanol, 1-propanol, 2-propanol, etc.), and dimethylformamide, but also solvates with multiple solvents.

[0081] As used herein, "amino acid" includes natural amino acids and unnatural amino acids. As used herein, "natural amino acids" refers to Gly, Ala, Ser, Thr, Val, Leu, Ile, Phe, Tyr, Trp, His, Glu, Asp, Gln, Asn, Cys, Met, Lys, Arg, and Pro. Unnatural amino acids are not particularly limited, but examples include β-amino acids, γ-amino acids, D-amino acids, N-substituted amino acids, α,α-disubstituted amino acids, amino acids with side chains that are different from natural amino acids, and hydroxycarboxylic acids. As used herein, amino acids may have any configuration. The side chain of the amino acid is not particularly limited, and may be freely selected from, in addition to a hydrogen atom, for example, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an aralkyl group, and a cycloalkyl group. In these groups, one or two non-adjacent methylene groups may be replaced by an oxygen atom, a carbonyl group (-CO-), or a sulfonyl group (-SO ２ -). Each of these may be substituted with a substituent, and the substituents are not limited, and may be independently selected from any substituents containing a halogen atom, an O atom, a S atom, a N atom, a B atom, a Si atom, or a P atom. That is, examples include optionally substituted alkyl groups, alkenyl groups, alkynyl groups, aryl groups, heteroaryl groups, aralkyl groups, and cycloalkyl groups. In a non-limiting embodiment, the amino acid herein may be a compound having a carboxy group and an amino group in the same molecule (even in this case, imino acids such as proline and hydroxyproline are also included in the amino acid).

[0082] As used herein, the term "side chain of an amino acid" refers to, in the case of an α-amino acid, an atomic group attached to the carbon atom (α-carbon) to which the amino group and carboxyl group are attached. For example, the methyl group of Ala is the side chain of an amino acid. In the case of a β-amino acid, the atomic group attached to the α-carbon and / or the β-carbon can be the side chain of the amino acid, and in the case of a γ-amino acid, the atomic group attached to the α-carbon, the β-carbon, and / or the γ-carbon can be the side chain of the amino acid.

[0083] As used herein, the term "main chain of an amino acid" refers to the chain portion composed of an amino group, an α-carbon, and a carboxyl group in the case of an α-amino acid, the chain portion composed of an amino group, a β-carbon, an α-carbon, and a carboxyl group in the case of a β-amino acid, and the chain portion composed of an amino group, a γ-carbon, a β-carbon, an α-carbon, and a carboxyl group in the case of a γ-amino acid.

[0084] As used herein, the terms "main chain of a peptide," "main chain of a peptide compound," and "main chain of a cyclic peptide compound" refer to a structure formed by linking multiple "main chains of amino acids" via amide bonds.

[0085] The main chain amino group of the amino acid is unsubstituted (NH ２ group), and may be substituted (i.e., an —NHR group: R represents an alkyl, alkenyl, alkynyl, aryl, heteroaryl, aralkyl, or cycloalkyl group which may have a substituent, and one or two non-adjacent methylene groups in these groups are replaced by an oxygen atom, a carbonyl group (—CO—), or a sulfonyl group (—SO ２ -), or the carbon chain bonded to the N atom and the carbon atom at the α-position may form a ring, as in proline. The substituent of R is selected in the same manner as the substituent in the amino acid side chain described above. When the main chain amino group is substituted, R is included in the "amino acid side chain" in this specification. An amino acid in which such a main chain amino group is substituted is referred to as an "N-substituted amino acid" in this specification. As used herein, the "N-substituted amino acid" is preferably an N-alkyl amino acid, an N-C １ -C ６ Alkylamino acid, N-C １ -C ４ Examples of N-substituted amino acids include, but are not limited to, alkylamino acids and N-methylamino acids. Note that proline is a natural amino acid and is therefore excluded from non-natural N-substituted amino acid residues.

[0086] The "amino acids" constituting the peptide compounds herein include all corresponding isotopes. An isotope of an "amino acid" is one in which at least one atom has been replaced with an atom having the same atomic number (number of protons) but a different mass number (the sum of the number of protons and neutrons), in an abundance ratio different from the natural abundance ratio. Examples of isotopes contained in the "amino acids" constituting the peptide compounds of the present invention include hydrogen atoms, carbon atoms, nitrogen atoms, oxygen atoms, phosphorus atoms, sulfur atoms, fluorine atoms, and chlorine atoms, each of which is ２ H. ３ H. １３ C. １４ C. １５ N. １７ O. １８ O. ３１ P. ３２ P. ３５ S. １８ F. ３６ Cl and the like are included.

[0087] In this specification, examples of the substituent containing a halogen atom include an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an aralkyl group, and the like, each of which has a halogen atom as a substituent, and more specific examples thereof include a fluoroalkyl, a difluoroalkyl, a trifluoroalkyl, and the like.

[0088] Substituents containing an O atom include hydroxy (-OH), oxy (-OR), carbonyl (-C=O-R), carboxy (-CO ２ H), oxycarbonyl (-C=O-OR), carbonyloxy (-O-C=O-R), thiocarbonyl (-C=O-SR), carbonylthio (-S-C=O-R), aminocarbonyl (-C=O-NHR), carbonylamino (-NH-C=O-R), oxycarbonylamino (-NH-C=O-OR), sulfonylamino (-NH-SO ２ -R), aminosulfonyl (-SO ２ -NHR), sulfamoylamino (-NH-SO ２ -NHR), thiocarboxyl (-C(=O)-SH), carboxylcarbonyl (-C(=O)-CO ２ H).

[0089] Examples of oxy (—OR) include alkoxy, cycloalkoxy, alkenyloxy, alkynyloxy, aryloxy, heteroaryloxy, aralkyloxy, etc. Alkoxy includes C １ -C ４ Alkoxy, C １ -C ２ Alkoxy is preferred, and methoxy or ethoxy is particularly preferred.

[0090] Examples of carbonyl (-C=O-R) include formyl (-C=O-H), alkylcarbonyl, cycloalkylcarbonyl, alkenylcarbonyl, alkynylcarbonyl, arylcarbonyl, heteroarylcarbonyl, aralkylcarbonyl, and the like.

[0091] Examples of oxycarbonyl (-C=O-OR) include alkyloxycarbonyl, cycloalkyloxycarbonyl, alkenyloxycarbonyl, alkynyloxycarbonyl, aryloxycarbonyl, heteroaryloxycarbonyl, aralkyloxycarbonyl, and the like.

[0092] Examples of carbonyloxy (—O—C═O—R) include alkylcarbonyloxy, cycloalkylcarbonyloxy, alkenylcarbonyloxy, alkynylcarbonyloxy, arylcarbonyloxy, heteroarylcarbonyloxy, and aralkylcarbonyloxy.

[0093] Examples of thiocarbonyl (-C=O-SR) include alkylthiocarbonyl, cycloalkylthiocarbonyl, alkenylthiocarbonyl, alkynylthiocarbonyl, arylthiocarbonyl, heteroarylthiocarbonyl, aralkylthiocarbonyl, and the like.

[0094] Examples of carbonylthio (-S-C=O-R) include alkylcarbonylthio, cycloalkylcarbonylthio, alkenylcarbonylthio, alkynylcarbonylthio, arylcarbonylthio, heteroarylcarbonylthio, aralkylcarbonylthio, and the like.

[0095] Examples of aminocarbonyl (—C═O—NHR) include alkylaminocarbonyl (e.g., C １ -C ６ or C １ -C ４ Examples include alkylaminocarbonyl, especially ethylaminocarbonyl and methylaminocarbonyl, cycloalkylaminocarbonyl, alkenylaminocarbonyl, alkynylaminocarbonyl, arylaminocarbonyl, heteroarylaminocarbonyl, aralkylaminocarbonyl, etc. In addition to these, examples include groups in which the H atom bonded to the N atom in —C═O—NHR is further substituted with an alkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, or aralkyl.

[0096] Examples of carbonylamino (-NH-C=O-R) include alkylcarbonylamino, cycloalkylcarbonylamino, alkenylcarbonylamino, alkynylcarbonylamino, arylcarbonylamino, heteroarylcarbonylamino, aralkylcarbonylamino, etc. In addition to these, there are also groups in which the H atom bonded to the N atom in -NH-C=O-R is further substituted with an alkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, or aralkyl.

[0097] Examples of oxycarbonylamino (-NH-C=O-OR) include alkoxycarbonylamino, cycloalkoxycarbonylamino, alkenyloxycarbonylamino, alkynyloxycarbonylamino, aryloxycarbonylamino, heteroaryloxycarbonylamino, aralkyloxycarbonylamino, etc. In addition to these, examples include groups in which the H atom bonded to the N atom in -NH-C=O-OR is further substituted with an alkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, or aralkyl.

[0098] Sulfonylamino (-NH-SO ２Examples of —R) include alkylsulfonylamino, cycloalkylsulfonylamino, alkenylsulfonylamino, alkynylsulfonylamino, arylsulfonylamino, heteroarylsulfonylamino, aralkylsulfonylamino, etc. In addition to these, —NH—SO ２ Examples include groups in which the H atom bonded to the N atom in —R is further substituted with alkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, or aralkyl.

[0099] Aminosulfonyl (-SO ２ Examples of —NHR) include alkylaminosulfonyl, cycloalkylaminosulfonyl, alkenylaminosulfonyl, alkynylaminosulfonyl, arylaminosulfonyl, heteroarylaminosulfonyl, aralkylaminosulfonyl, and the like. ２ Examples include groups in which the H atom bonded to the N atom in —NHR is further substituted with alkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, or aralkyl.

[0100] Sulfamoylamino (-NH-SO ２ Examples of —NHR) include alkylsulfamoylamino, cycloalkylsulfamoylamino, alkenylsulfamoylamino, alkynylsulfamoylamino, arylsulfamoylamino, heteroarylsulfamoylamino, and aralkylsulfamoylamino. ２ The two H atoms bonded to the N atom in —NHR may be substituted with substituents independently selected from the group consisting of alkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, and aralkyl, and these two substituents may form a ring.

[0101] Substituents containing an S atom include thiol (-SH), thio (-S-R), sulfinyl (-S=O-R), and sulfonyl (-SO ２ -R), sulfo (-SO ３ H).

[0102] Examples of thio (-S-R) are selected from alkylthio, cycloalkylthio, alkenylthio, alkynylthio, arylthio, heteroarylthio, aralkylthio, and the like.

[0103] Sulfonyl (-SO ２ Examples of —R) include alkylsulfonyl, cycloalkylsulfonyl, alkenylsulfonyl, alkynylsulfonyl, arylsulfonyl, heteroarylsulfonyl, aralkylsulfonyl, and the like.

[0104] As a substituent containing a nitrogen atom, azide (-N ３ , also called "azido group"), cyano (-CN), primary amino (-NH ２ ), secondary amino (-NH-R; also called monosubstituted amino), tertiary amino (-NR(R'); also called disubstituted amino), amidino (-C(=NH)-NH ２ ), substituted amidino (—C(═NR)—NR′R″), guanidino (—NH—C(═NH)—NH ２ ), substituted guanidino (—NR—C(═NR′″)—NR′R″), aminocarbonylamino (—NR—CO—NR′R″), pyridyl, piperidino, morpholino, azetidinyl, and the like.

[0105] Examples of secondary amino (-NH-R; monosubstituted amino) include alkylamino, cycloalkylamino, alkenylamino, alkynylamino, arylamino, heteroarylamino, and aralkylamino.

[0106] Examples of tertiary amino (—NR(R′); disubstituted amino) include an amino group having any two substituents independently selected from alkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, aralkyl, etc., such as alkyl(aralkyl)amino, and these two substituents may form a ring. Specifically, dialkylamino, especially C １ -C ６ Dialkylamino, C １ -C ４Examples include dialkylamino, dimethylamino, and diethylamino. ｐ -C ｑ "Dialkylamino group" means an amino group having C ｐ -C ｑ It means a group substituted with two alkyl groups, and both C ｐ -C ｑ The alkyl groups may be the same or different.

[0107] Examples of substituted amidino (-C(=NR)-NR'R") include groups in which the three substituents R, R', and R" on the N atom are each independently selected from alkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, and aralkyl, such as alkyl(aralkyl)(aryl)amidino.

[0108] Examples of substituted guanidino (-NR-C(=NR'")-NR'R") include groups in which R, R', R", and R'" are each independently selected from alkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, and aralkyl, or groups in which these groups form a ring.

[0109] Examples of aminocarbonylamino (-NR-CO-NR'R") include groups in which R, R', and R" are each independently selected from a hydrogen atom, alkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, and aralkyl, or groups in which these groups form a ring.

[0110] In this specification, the "amino acid residues" that constitute a peptide compound may be simply referred to as "amino acids".

[0111] As used herein, the term "linear peptide compound" is not particularly limited as long as it is formed by linking natural amino acids and / or unnatural amino acids via amide bonds or ester bonds and does not have a cyclic moiety. The total number of natural and unnatural amino acids constituting the linear peptide compound can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, or 30, with preferred ranges being 6 to 20, 7 to 19, 7 to 18, 7 to 17, 7 to 16, 7 to 15, 8 to 14, and 9 to 13.

[0112] As used herein, the term "cyclic peptide compound" refers to a compound formed by linking natural amino acids and / or unnatural amino acids via amide bonds or ester bonds, and is not particularly limited as long as it has a cyclic moiety. The total number of natural and unnatural amino acids constituting the cyclic peptide compound can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, or 30, with preferred ranges being 6 to 20, 7 to 19, 7 to 18, 7 to 17, 7 to 16, 7 to 15, 8 to 14, and 9 to 13.

[0113] As used herein, the "cyclic portion" of a peptide compound refers to a cyclic portion formed by linking two or more amino acid residues. Furthermore, as used herein when referring to a partial structure of a cyclic peptide compound, the "linear portion" refers to a portion that is not included in the main chain structure of the cyclic portion and has at least one amide bond and / or ester bond in the chain of the linear portion.

[0114] The number of amino acids constituting the cyclic portion of the cyclic peptide compound herein is not limited, and examples include 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, 10 or more, 11 or more, 12 or more, 30 or less, 20 or less, 18 or less, 16 or less, 15 or less, 14 or less, 13 or less, 12 or less, 11 or less, 7, 8, 9, 10, 11, 12, 13, 14, 15, and 16. In consideration of both membrane permeability and metabolic stability, the number of amino acids constituting the cyclic portion is preferably 2 to 30, 2 to 15, or 5 to 15, more preferably 5 to 14, 7 to 14, or 8 to 14, even more preferably 8 to 13, 9 to 13, 8 to 12, 8 to 11, or 9 to 12, and particularly preferably 9 to 11.

[0115] In one embodiment, the number of amino acids (number of units) in the linear portion is preferably 0 to 8, more preferably 0 to 5, and even more preferably 0 to 3. In a non-limiting embodiment, the "linear portion" herein may include natural amino acids and unnatural amino acids (including chemically modified or backbone-converted amino acids).

[0116] In some embodiments, the molecular weight of the cyclic peptide compounds herein may be between 500 and 2000.

[0117] The "peptide compound" herein may include pharmaceutically acceptable salts thereof or solvates thereof.

[0118] As used herein, the term "side chain" is used in the context of the side chain of an amino acid or the side chain of the cyclic portion of a cyclic peptide compound, and refers to a portion that is not included in the respective main chain structures.

[0119] As used herein, the term "number of amino acids" refers to the number of amino acid residues (amino acid units) that constitute a peptide compound, and refers to the number of amino acid units that are generated when the amide bond, ester bond, and bond at the cyclization site that link the amino acids are cleaved.

[0120] As used herein, the term "elongation reaction" refers to a reaction in which an amino acid or a peptide is elongated. The elongation reaction can be carried out by solid-phase synthesis, which is carried out on an amino acid or a peptide supported on a solid-phase synthesis resin, or by liquid-phase synthesis, which does not use a solid-phase synthesis resin.

[0121] As used herein, the term "supported on a resin for solid phase synthesis" means that an amino acid or peptide is bound to a resin for solid phase synthesis to which no amino acid or peptide has been bound.

[0122] As used herein, the term "and / or" includes any combination of "and" and "or." Specifically, for example, "A, B, and / or C" includes the following seven variations: (i) A, (ii) B, (iii) C, (iv) A and B, (v) A and C, (vi) B and C, and (vii) A, B, and C.

[0123] (Production Method) In one aspect, the present invention relates to a method for producing a peptide compound comprising at least one N-substituted amino acid residue, a salt thereof, or a solvate thereof by a solid phase method, characterized in that the peptide is supported on a resin for solid phase synthesis before the first elongation reaction in the solid phase method. Also, in one aspect, the present invention relates to a method for producing a peptide compound comprising at least one N-substituted amino acid residue, a salt thereof, or a solvate thereof by a solid phase method, comprising a step of supporting the peptide on a resin for solid phase synthesis.

[0124] That is, the present invention involves supporting a peptide such as an oligopeptide, which has been prepared in advance by a liquid phase method or the like, on a resin for solid phase synthesis, and then carrying out peptide chain elongation of the peptide in a solid phase method, thereby synthesizing a peptide compound having a desired amino acid sequence. In this specification, the peptide supported on a resin for solid phase synthesis before the first elongation reaction in the solid phase method may be referred to as the "starting peptide."

[0125] In this specification, the first extension reaction preferably extends the starting peptide with an amino acid.

[0126] Conventionally, peptide compounds have been produced using solid-phase synthesis by loading amino acids onto a solid-phase synthesis resin and then sequentially elongating the amino acids. However, in this method, during the condensation step for elongating the next amino acid (the second amino acid residue) to the amino acid (the first amino acid residue) loaded on the solid-phase synthesis resin, the first amino acid residue may be detached from the solid-phase synthesis resin (premature cleavage). Such detachment is more pronounced when a solid-phase synthesis resin capable of cleaving peptide compounds under mild conditions is used. Furthermore, prior to the elongation of the second amino acid residue, the first amino acid residue detached by premature cleavage may be elongated to the first amino acid residue, and then the second amino acid residue may be elongated, resulting in the by-product of an over-elongated product. Furthermore, for some unnatural amino acid residues, the elongation reaction by the solid-phase method, for example, the elongation reaction from the first amino acid residue to the second amino acid residue, may not proceed sufficiently, and the next amino acid may be linked while the second amino acid residue remains missing. This is particularly true when the second amino acid residue is an N-substituted amino acid residue with a bulky side chain. By using the method of the present invention, these drawbacks can be avoided and desired peptide compounds can be produced in high yield and with high purity.

[0127] In the present invention, the starting peptide can contain any number and type of amino acid residues. Specific examples of such peptides include oligopeptides containing two or more amino acid residues, with dipeptides or tripeptides being preferred. Furthermore, it is preferable that the amino group of the N-terminal amino acid residue of the starting peptide be protected with a protecting group. Such starting peptides can be produced using methods known in the art, such as liquid-phase synthesis. There are no limitations on the method for preparing the N-terminally protected starting peptide. For example, specifically, a carboxyl-protected amino acid residue can be subjected to an elongation reaction of the amino acid residue using an amino acid residue with a protected amino group and a condensing agent, followed by deprotection of the N-terminal protecting group and elongation of the amino acid with the protected amino group. This process can be repeated until the desired number of residues is reached, and finally, deprotection of the C-terminal protecting group can be performed. The amino acid residues used as raw materials for producing the starting peptide can be obtained from commercial suppliers or can be produced by known methods, such as those described in WO 2018 / 225864.

[0128] In one embodiment, the starting peptide has a C-terminal amino acid residue (the first amino acid residue) that is an unnatural amino acid residue, and the unnatural amino acid residue is preferably an N-substituted amino acid residue such as an N-alkyl amino acid. １ -C ６ Alkylamino acids are preferred, and N-methylamino acids are more preferred. Without being bound by any particular theory, when the first amino acid residue is an N-substituted amino acid residue, premature cleavage tends to occur more easily than when it is an N-unsubstituted amino acid residue, and this tendency is more pronounced when the first amino acid residue has a bulky group in its side chain. Therefore, the present invention is particularly useful for producing peptide compounds containing such an amino acid residue as the C-terminal amino acid residue.

[0129] In one embodiment, the C-terminal amino acid residue (the first amino acid residue) of the starting peptide is supported on a solid-phase synthesis resin via a carboxyl group bonded to the α-, β-, or γ-carbon atom of the amino group. An example of an amino acid residue supported on a solid-phase synthesis resin via a carboxyl group bonded to the β-carbon atom of the amino group is aspartic acid or a derivative thereof. Specifically, the case where an aspartic acid is supported on a solid-phase synthesis resin via a carboxyl group present in its side chain corresponds to the case where an aspartic acid is supported on a solid-phase synthesis resin via a carboxyl group bonded to the β-carbon atom of the amino group. Furthermore, an example of an amino acid residue supported on a solid-phase synthesis resin via a carboxyl group bonded to the γ-carbon atom of the amino group is glutamic acid or a derivative thereof. Specifically, the case where an aspartic acid is supported on a solid-phase synthesis resin via a carboxyl group present in its side chain corresponds to the case where an aspartic acid is supported on a solid-phase synthesis resin via a carboxyl group bonded to the γ-carbon atom of the amino group. Other natural amino acid residues and their N-substituted amino acid residues are usually supported on a resin for solid phase synthesis via a carboxyl group bonded to the α-carbon atom.

[0130] In certain embodiments, the starting peptide's C-terminal amino acid residue (the first amino acid residue) can be aspartic acid, 2-aminobutanoic acid, glycine, alanine, valine, proline, tyrosine, or 2-aminoisobutyric acid, or N-substituted and / or derivatives thereof. When the first amino acid residue is one of these amino acid residues, premature cleavage is likely to occur. N-substituted amino acids of these amino acid residues are preferably N-alkylated, more preferably N-methylated. Derivatives of these amino acid residues include those in which any functional group (e.g., amino, carboxyl, hydroxyl, etc.) not involved in the bond between the solid-phase synthesis resin and the second amino acid residue is protected with an optional substituent (e.g., a protecting group). Particularly, specific examples of aspartic acid derivatives include those in which the free carboxyl group not involved in the bond between the solid-phase synthesis resin and the second amino acid residue is aminocarbonylated. Specific examples of aminocarbonylated aspartic acids include dialkylaminocarbonylated aspartic acids such as dimethylaminocarbonyl, and aspartic acids aminocarbonylated with the N atom of a saturated heterocycle containing an N atom (e.g., an azetidine ring, a morpholine ring, a pyrrolidine ring, a piperidine ring, an azepane ring, etc.). These aspartic acids can also be N-substituted, such as N-alkylated. When the first amino acid residue is aspartic acid or its N-substituted derivatives and / or derivatives, the amino acid residue is preferably supported on a solid-phase synthesis resin via the carboxyl group at the β-position of the amino group. Examples of amino acid residues in which any functional group (e.g., amino group, carboxyl group, hydroxyl group, etc.) is protected with any protecting group include those in which the amino group in the side chain of the amino acid residue is protected with a carbamate-type protecting group such as a Boc group or a Cbz group, and specifically, for example, those in which the amino group in the side chain of Lys is protected with a Boc group.Other examples include those in which the amide group in the side chain of an amino acid residue is protected with an alkylamine-type protecting group such as a t-Bu group or a Trt group, specifically, for example, those in which the amide group in the side chain of Asn or Gln is protected with a Trt group, and those in which the hydroxyl group in the side chain of an amino acid residue is protected with an alkyl ether-type protecting group such as a t-Bu group, specifically, for example, those in which the hydroxyl group in the side chain of Ser, the hydroxyl group in the side chain of Thr, or the hydroxyl group in the side chain of Tyr is protected with a t-Bu group.

[0131] In some embodiments, the starting peptide may have an unnatural amino acid residue as the amino acid residue adjacent to the C-terminal amino acid residue (the second amino acid residue). The unnatural amino acid residue is preferably an N-substituted amino acid residue such as an N-alkylamino acid and / or an amino acid derivative, and the N-substituted amino acid residue is preferably an N-methyl form. Examples of amino acid residue derivatives include those in which any functional group (e.g., amino group, carboxyl group, hydroxyl group, etc.) not involved in the bond with the adjacent amino acid residue is protected with any substituent (e.g., protecting group). Specific examples include those in which the amino group in the side chain of the amino acid residue is protected with a carbamate-type protecting group such as a Boc group or a Cbz group, and more specifically, for example, those in which the amino group in the side chain of Lys is protected with a Boc group. Other examples include those in which the amide group in the side chain of an amino acid residue is protected with an alkylamine-type protecting group such as a t-Bu group or a Trt group, specifically, for example, those in which the amide group in the side chain of Asn or Gln is protected with a Trt group, and those in which the hydroxyl group in the side chain of an amino acid residue is protected with an alkyl ether-type protecting group such as a t-Bu group, specifically, for example, those in which the hydroxyl group in the side chain of Ser, the hydroxyl group in the side chain of Thr, or the hydroxyl group in the side chain of Tyr is protected with a t-Bu group. Without being bound by any particular theory, when the second amino acid residue is an N-substituted amino acid residue, premature cleavage tends to occur more easily than when the second amino acid residue is an N-unsubstituted amino acid residue, and this tendency is particularly pronounced when the second amino acid residue has a bulky group in its side chain. Therefore, the present invention is particularly useful for producing peptide compounds containing such an amino acid residue as the second residue.

[0132] In one embodiment, the starting peptide may have a C-terminal amino acid residue (first amino acid residue) and an amino acid residue adjacent to the C-terminal amino acid residue (second amino acid residue) that are both naturally occurring amino acid residues, but it is preferred that one or both of them be unnatural amino acid residues.

[0133] In some embodiments, the C-terminal amino acid residue (the first amino acid residue) of the starting peptide and / or the amino acid residue adjacent to the C-terminal amino acid residue (the second amino acid residue) have a bulky side chain. Examples of natural amino acids having bulky side chains include amino acids having a side chain with two or more carbon atoms, such as Met, Phe, Tyr, Val, Leu, Ile, Trp, Arg, His, Glu, Lys, Gln, Asp, Asn, Cys, and Thr. Furthermore, an amino acid residue having a bulky side chain may also be considered to have a bulky side chain if it has a bulky protecting group on the side chain. For example, Ser itself does not have a bulky side chain, but Ser(tBu) in which the side chain of Ser is protected with tBu is an amino acid residue having a bulky side chain. Furthermore, whether natural or unnatural, an amino acid residue having a branched-chain alkyl group optionally substituted on its side chain may be an amino acid residue having a bulky side chain. Such a branched-chain alkyl group is preferably bonded to the α-carbon atom of the carboxyl group of the amino acid residue, and the branching position of the branched-chain alkyl group is preferably the β-carbon atom or the γ-carbon atom of the carboxyl group. For example, Val is an example of an amino acid residue having a branched-chain alkyl group on the α-carbon atom of the carboxyl group of the amino acid residue and a branched chain on the β-carbon atom, and a Val-like amino acid residue may be an amino acid residue having a bulky side chain. Furthermore, Leu is an example of an amino acid residue having a branched-chain alkyl group on the α-carbon atom of the carboxyl group of the amino acid residue and a branched chain on the γ-carbon atom, and a Leu-like amino acid may be an amino acid residue having a bulky side chain.The number and type of substituents that the branched-chain alkyl group may have are not particularly limited, but the branched-chain alkyl group may have 1 to 5 substituents independently selected from the group consisting of alkenyl, alkynyl, cycloalkyl, aryl, heterocyclyl, heteroaryl, alkoxy, alkenyloxy, cycloalkoxy, aryloxy, amino, aminocarbonyl, alkenyloxycarbonyl, alkylsulfonyl, hydroxy, halogen, cyano, carboxy, alkenyloxycarbonyl, aralkoxy, heteroarylalkoxy, alkoxyalkenyl, aminocarbonylalkenyl, and haloalkoxy. Without being bound by any particular theory, when the first amino acid residue and / or the second amino acid residue has a bulky side chain, premature cleavage is likely to occur, and therefore the present invention is particularly useful for producing peptide compounds containing such amino acids.

[0134] In one embodiment, the C-terminal amino acid residue (first amino acid residue) of the starting peptide can be represented by the following formula (A):

[0135] In formula (A), L １ is a single bond or -CHM １ -, -CH ２ CHM １ -, -CHM １ CH ２ -, -(CH ２ ) ｎ S (CH ２ ) ｍ -, -(CH ２ ) ｎ S(O)(CH ２ ) ｍ - or - (CH ２ ) ｎ S (O) ２ (CH ２ ) ｍ -, where n and m are each independently 1 or 2.

[0136] L １ But -(CH ２ ) ｎ S (CH ２ ) ｍ-, -(CH ２ ) ｎ S (CH ２ ) ｍ Specific examples of - include -CH ２ SCH ２ -, -CH ２ CH ２ SCH ２ -, -CH ２ SCH ２ CH ２ -, -CH ２ CH ２ SCH ２ CH ２ - and others.

[0137] L １ But -(CH ２ ) ｎ S(O)(CH ２ ) ｍ -, -(CH ２ ) ｎ S(O)(CH ２ ) ｍ Specific examples of - include -CH ２ S(O)CH ２ -, -CH ２ CH ２ S(O)CH ２ -, -CH ２ S(O)CH ２ CH ２ -, -CH ２ CH ２ S(O)CH ２ CH ２ - and others.

[0138] L １ But -(CH ２ ) ｎ S (O) ２ (CH ２ ) ｍ -, -(CH ２ ) ｎ S (O) ２ (CH ２ ) ｍ Specific examples of - include -CH ２ S (O) ２ CH ２ -, -CH ２ CH ２S (O) ２ CH ２ -, -CH ２ S (O) ２ CH ２ CH ２ -, -CH ２ CH ２ S (O) ２ CH ２ CH ２ - and others.

[0139] In formula (A), R １ is hydrogen, C １ -C ６ Alkyl, C ２ -C ６ Alkenyl, C ２ -C ６ Alkynyl, C １ -C ６ Alkoxy C １ -C ６ Alkyl, C ７ -C １４ aralkyl, or aminocarbonyl (wherein the amino is —NH ２ , Mono C １ -C ６ Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino), each of which is selected from halogen, oxo, hydroxy, C １ -C ６ Alkyl, 4- to 7-membered heterocyclyl, aminocarbonyl (wherein the amino is -NH ２ , Mono C １ -C ６ Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino), C １ -C ６ Alkylsulfonyl, and C １ -C ６ Alkoxy C １ -C ６ alkyl, or R １ is a peptide chain containing 1 to 4 amino acid residues. １is a peptide chain containing 1 to 4 amino acid residues, the 1 to 4 amino acid residues constituting the peptide chain may be natural amino acid residues or non-natural amino acid residues, and may be the same or different.

[0140] L １ is a single bond, R １ is hydrogen, C １ -C ６ C optionally substituted by alkyl or hydroxy １ -C ６ Alkoxy C １ -C ６ alkyl, or one or more halogens or C １ -C ６ Alkoxy C １ -C ６ C optionally substituted by alkyl ７ -C １４ Aralkyl is preferred.

[0141] L １ is a single bond, R １ More preferably, C optionally substituted by hydrogen, methyl, isopropyl, hydroxy １ -C ６ Alkoxy C １ -C ２ Benzyl optionally substituted by alkyl, fluorine or t-butoxy, and specific examples include hydrogen, (2-hydroxy-2-methyl-propyloxy)methyl, benzyl, 3-fluorobenzyl and 4-fluorobenzyl.

[0142] L １ Ga-CHM １ -, -CH ２ CHM １ - or -CHM １ CH ２ -, then R １ is hydrogen, C １ -C ６ Alkyl, haloC １ -C ６ Alkyl, C ２ -C ６ Alkenyl, C ２ -C ６Alkynyl, C １ -C ６ Alkoxy C １ -C ６ Alkyl (the C １ -C ６ Alkoxy C １ -C ６ Alkyl is hydroxy, or aminocarbonyl (wherein the amino is -NH ２ , Mono C １ -C ６ Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino), C optionally substituted by one or more halogens ７ -C １４ aralkyl, or aminocarbonyl (wherein the amino is —NH ２ , Mono C １ -C ６ Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino, wherein the cyclic amino is selected from the group consisting of one or more halogens, one or more oxo, one or more C １ -C ６ It is preferred that the aryl group is aryl, which may be further substituted by alkyl, or 4- to 7-membered heterocyclyl.

[0143] L １ Ga-CHM １ -, -CH ２ CHM １ - or -CHM １ CH ２ -, then R １ More preferably, hydrogen, C １ -C ６ Alkyl, C １ -C ６ Fluoroalkyl, C ２ -C ３ Alkenyl, C ２ -C ３ Alkynyl, Mono C １ -C ４ C optionally substituted by alkylaminocarbonyl １ -C ６ Alkoxy C１ -C ２ alkyl, dimethylaminocarbonyl; one or more fluorines, C １ -C ４ 4- to 8-membered cyclic aminocarbonyl optionally substituted by alkyl or 4- to 7-membered heterocyclyl; benzyl, phenethyl.

[0144] L １ Ga-CHM １ -, -CH ２ CHM １ - or -CHM １ CH ２ -, then R １ Specific examples of the alkyl group include hydrogen, methyl, isobutyl, trifluoromethyl, allyl, prop-2-yn-1-yl, (isopentyloxy)methyl, {2-(t-butylamino)-2-oxoethoxy}methyl, dimethylaminocarbonyl, azetidinylcarbonyl, pyrrolidinylcarbonyl, 3,3-dimethylpyrrolidinylcarbonyl, 3,3,4,4-tetrafluoropyrrolidinylcarbonyl, 4-methylpiperidinylcarbonyl, and 4-(t-butyl)-piperidinylcarbonyl. Examples include 3,3,4,4,5,5-hexafluoropiperidinylcarbonyl, 3,3-difluoropiperidinylcarbonyl, 4,4-difluoropiperidinylcarbonyl, piperidinylcarbonyl, morpholinocarbonyl, oxazolidin-3-ylcarbonyl, 3-oxa-8-azabicyclo[3.2.1]octan-8-ylcarbonyl, 1,1-dioxidethiomorpholinylcarbonyl, 1-(oxetan-3-yl)-piperazin-4-ylcarbonyl, and phenethyl.

[0145] L １ But -(CH ２ ) ｎ S (CH ２ ) ｍ -, -(CH ２ ) ｎ S(O)(CH ２ ) ｍ Or, -(CH ２ ) ｎ S (O) ２ (CH ２ ) ｍ -, then R１ is an aminocarbonyl (the amino is —NH ２ , Mono C １ -C ６ Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino).

[0146] In formula (A), R １ and P １ is R １ and the carbon atom to which P is bonded. １ together with the nitrogen atom to which it is attached can form a 4- to 7-membered saturated heterocyclic ring.

[0147] R １ and P １ When forms a 4- to 7-membered saturated heterocyclic ring, the 4- to 7-membered saturated heterocyclic ring is preferably an azetidine ring, a pyrrolidine ring, a piperidine ring, a piperazine ring or a morpholine ring.

[0148] In formula (A), R １ and Q １ can be taken together with the carbon atoms to which they are attached to form a 3- to 8-membered alicyclic ring or a 4- to 7-membered saturated heterocyclic ring.

[0149] R １ and Q １ forms a 3- to 8-membered alicyclic ring or a 4- to 7-membered saturated heterocyclic ring, the 3- to 8-membered alicyclic ring is preferably a cyclopropane ring, a cyclobutane ring, a cyclopentane ring or a cyclohexane ring, and the 4- to 7-membered saturated heterocyclic ring is preferably a tetrahydrofuran ring or a tetrahydropyran ring.

[0150] In formula (A), L １ Ga-CHM １ -, -CH ２ CHM １ - or -CHM １ CH ２ -, then R １ and M １ is R １ and the carbon atom to which M is bonded. １ together with the carbon atom to which it is attached can form a 3- to 8-membered alicyclic ring.

[0151] R １ and M １ When forms a 3- to 8-membered alicyclic ring, the 3- to 8-membered alicyclic ring is preferably a cyclopentane ring or a cyclohexane ring.

[0152] In formula (A), L １ Ga-CHM １ -, -CH ２ CHM １ - or -CHM １ CH ２ -, then R １ and M １ forms a 3- to 8-membered alicyclic ring, M １ is hydrogen.

[0153] In formula (A), R １ and P １ forms a 4- to 7-membered saturated heterocyclic ring, １ is hydrogen or C １ -C ６ alkyl, and the C １ -C ６ Alkyl is substituted with halogen, hydroxy, C １ -C ６ Alkoxy, amino (the amino is —NH ２ , Mono C １ -C ６ Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino, each of which may be substituted with halogen), and aminocarbonyl (the amino is —NH ２ , Mono C １ -C ６ Alkylamino, DiC １ -C ６ The amino group may be substituted with one or more groups independently selected from the group consisting of alkylamino, alkylamino, or 4- to 8-membered cyclic amino.

[0154] P １ is preferably hydrogen, C １ -C ６ Such P １ Specific examples of the alkyl group include hydrogen, methyl, ethyl, and n-propyl.

[0155] R １ and Q １ Q forms a 3- to 8-membered alicyclic ring or a 4- to 7-membered saturated heterocyclic ring, １ is hydrogen or C １ -C ６ It is alkyl, preferably hydrogen or methyl.

[0156] R １ Ga-CONR １Ａ R １Ｂ where R １Ａ and R １Ｂ are each independently hydrogen or C １ -C ６ alkyl (preferably methyl), or R １Ａ and R １Ｂ together with the nitrogen atom to which they are attached form a 4- to 8-membered saturated heterocyclic ring, which may be substituted with one or more halogens (preferably fluorine), one or more oxo, one or more C １ -C ６ Alkyl (preferably C １ -C ４ and 4- to 7-membered heterocyclyl (preferably oxetan-3-yl).

[0157] In formula (A), * represents a binding site to a resin for solid phase synthesis, and a wavy line represents a binding site to an adjacent amino acid residue.

[0158] L １ is a single bond, specific examples of the amino acid residue represented by formula (A) include MeSer(tBuOH), MeGly, MePhe, MePhe(3-F), MePhe(4-F), D-MePhe, MeVal, Pro, Aib, Ala, Gly, Tyr(tBu), and Val.

[0159] L １ Ga-CHM １-, specific examples of the amino acid residues represented by formula (A) include bAla, bMeAla, 2-ACHxC, 2-ACPnC, 3-CF3-bAla, Asp-mor, Asp-mor(26-bicyc), Asp-mor(SO2), Asp-NMe2, Asp-oxz, Asp-pip, Asp-pip(345-F6), Asp-pip(4-Me), Asp- pip-tBu, Asp-piz(oxe), Asp-pyrro, Asp-pyrro(34-F4), Asp-pyrro(3-Me2), D-(Propargyl)Gly-(C#C H2), D-3-Abu, D-3-MeAbu, D-Gly(Allyl)-(C#CH2), D-Hph-(C#CH2), D-Leu-(C#CH2), D-MeAsp-pyrro, D- MeLeu-(C#CH2), D-Pic(2)-(C#CH2), D-Pro-(C#CH2), D-Ser(iPen)-(C#CH2), D-Ser(NtBu-Aca)-(C#CH 2), EtAsp-pip, MeAsp-aze, MeAsp-mor, MeAsp-mor(26-bicyc), MeAsp-mor(SO2), MeAsp-NMe2, MeAsp-ox z, MeAsp-pip, MeAsp-pip(345-F6), MeAsp-pip(3-F2), MeAsp-pip(4-F2), MeAsp-pip(4-Me), MeAsp-pi Examples include z(oxe), MeAsp-pyrro, MeAsp-pyrro(34-F4), MeAsp-pyrro(3-Me2), nPrAsp-pip, and D-MeAsp-NMe2.

[0160] L １ Ga-CH ２ CHM １ - or -CHM １ CH ２ When -, specific examples of the amino acid residue represented by formula (A) include Glu-mor, Glu-pip, MeGlu-pip, Glu-NMe2, and MeGlu-NMe2.

[0161] L １ But -(CH ２ ) ｎ S (CH ２ ) ｍ-, -(CH ２ ) ｎ S(O)(CH ２ ) ｍ Or, -(CH ２ ) ｎ S (O) ２ (CH ２ ) ｍ When it is -, a specific example of the amino acid residue represented by formula (A) is MeCys(AcOH)-NMe2.

[0162] In one embodiment, the amino acid residue (the second amino acid residue) adjacent to the C-terminal amino acid residue of the starting peptide can be represented by the following formula (B).

[0163] In formula (B), L ２ is a single bond or -CH ２ - is.

[0164] In formula (B), R ２ is hydrogen, C １ -C ６ Alkyl, C ２ -C ６ Alkynyl, C １ -C ６ Alkoxy C １ -C ６ Alkyl, C ３ -C ８ Cycloalkyl, C ３ -C ８ Cycloalkyl C １ -C ６ Alkyl, C ３ -C ８ Cycloalkoxy C １ -C ６ Alkyl, or C ７ -C １４ and aralkyl, each of which is selected from halogen, hydroxy, amino (wherein the amino is -NH ２ , protected amino, mono C １ -C ６ Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino, each of which may be substituted with halogen), aminocarbonyl (the amino is —NH２ , protected amino, mono C １ -C ６ Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino), and C １ -C ６ It may be substituted with one or more groups independently selected from the group consisting of alkylsulfonyl.

[0165] L ２ is a single bond, R ２ is preferably hydrogen, C １ -C ６ Alkyl, haloC １ -C ６ Alkyl, hydroxy C １ -C ６ Alkyl, Amino C １ -C ６ Alkyl (the amino is -NH ２ , protected amino, mono C １ -C ６ Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino, each of which may be substituted with one or more halogens), aminocarbonyl C １ -C ６ Alkyl (the amino is -NH ２ , protected amino, mono C １ -C ６ Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino, each of which may be substituted with one or more halogens), C １ -C ６ Alkylsulfonyl C １ -C ６ Alkyl, C ２ -C ６ alkynyl, C optionally substituted by one or more halogens １ -C ６ Alkoxy C １ -C ６ Alkyl, C ３ -C ８Cycloalkyl, C ３ -C ８ Cycloalkyl C １ -C ６ Alkyl, C ３ -C ８ Cycloalkoxy C １ -C ６ Alkyl, or C ７ -C １４ It is aralkyl.

[0166] L ２ is a single bond, R ２ More preferably, C １ -C ６ Alkyl, Fluoro C １ -C ６ Alkyl, hydroxy C １ -C ４ Alkyl, protected amino C １ -C ４ Alkyl, protected aminocarbonyl C １ -C ４ Alkyl, methylsulfonyl C １ -C ２ Alkyl, C ２ -C ３ alkynyl, C optionally substituted by one or more fluorines １ -C ４ Alkoxy C １ -C ２ Alkyl, C ３ -C ６ Cycloalkyl, C ３ -C ６ Cycloalkyl C １ -C ２ Alkyl, C ３ -C ６ Cycloalkoxy C １ -C ２ alkyl, benzyl, and phenethyl.

[0167] L ２ is a single bond, R ２More specific examples of the alkyl group include methyl, ethyl, n-propyl, i-propyl, 2-methylpropyl, 1-methylpropyl, n-butyl, 2-methylbutyl, 3-methylbutyl, n-pentyl, propargyl, 3,3-difluorobutyl, 5,5-difluoropentyl, methoxymethyl, 1-methoxyethyl, 2-methoxyethyl, n-propoxymethyl, 1-hydroxyethyl, cyclopropoxymethyl, cyclobutoxymethyl, (2,2,2-trifluoroethoxy)methyl, 2-methylsulfonylethyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, cyclobutylmethyl, cyclopentylmethyl, cyclohexylmethyl, benzyl, phenethyl, 4-(t-butoxycarbonylamino)butyl, tritylaminocarbonylmethyl, and t-butoxymethyl.

[0168] L ２ Ga-CH ２ -, then R ２ Preferably, C １ -C ６ It is preferably alkyl, more preferably methyl.

[0169] In formula (B), R ２ and P ２ is R ２ and the carbon atom to which P is bonded. ２ together with the nitrogen atom to which it is attached can form a 4- to 7-membered saturated heterocyclic ring.

[0170] R ２ and P ２ When forms a 4- to 7-membered saturated heterocyclic ring, the 4- to 7-membered saturated heterocyclic ring is preferably an azetidine ring, a pyrrolidine ring, a piperidine ring, a piperazine ring or a morpholine ring.

[0171] In formula (B), R ２ and Q ２ can be taken together with the carbon atoms to which they are attached to form a 3- to 8-membered alicyclic ring or a 4- to 7-membered saturated heterocyclic ring.

[0172] R ２ and Q ２forms a 3- to 8-membered alicyclic ring or a 4- to 7-membered saturated heterocyclic ring, the 3- to 8-membered alicyclic ring is preferably a cyclopropane ring, a cyclobutane ring, a cyclopentane ring or a cyclohexane ring, and the 4- to 7-membered saturated heterocyclic ring is preferably a tetrahydrofuran ring or a tetrahydropyran ring.

[0173] In formula (B), R ２ and P ２ forms a 4- to 7-membered saturated heterocyclic ring, ２ is hydrogen or C １ -C ６ alkyl, and １ -C ６ Alkyl is substituted with halogen, hydroxy, C １ -C ６ Alkoxy, amino (the amino is —NH ２ , Mono C １ -C ６ Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino, each of which may be substituted with halogen), and aminocarbonyl (the amino is —NH ２ , Mono C １ -C ６ Alkylamino, DiC １ -C ６ and optionally substituted with one or more groups independently selected from the group consisting of alkylamino, 4- to 8-membered cyclic amino, or 4- to 8-membered cyclic amino. ２ is preferably hydrogen or C １ -C ２ It is alkyl, and specific examples thereof include hydrogen and methyl.

[0174] R ２ and Q ２ Q forms a 3- to 8-membered alicyclic ring or a 4- to 7-membered saturated heterocyclic ring, ２ is hydrogen or C １ -C ６ It is alkyl, preferably hydrogen or methyl.

[0175] * indicates the binding site with the C-terminal amino acid residue, and the wavy line indicates the binding site with the adjacent amino acid residue or the protecting group of the amino group.

[0176] Specific examples of the amino acid residues represented by formula (B) include MeAla, MeLeu, MeCha, MeVal, MeAla(cPent), MeAla(cBu), MeAla(cPr), MeChg, MeGly(cPent), MeGly(cBu), MeGly(cPr), MeAbu, MeNva, MeNle, Val, Leu, MeNva(5-F2), MeHle, MeIle, MeSer(nPr), MeSer(cPr), Me Hnl, MeHnl(7-F2), MePRA, MeSer(Me), MeThr, MeSer(cBu), MeSer(Tfe), MeThr(Me), MeHse(Me), MeMet(O2), Ile, Nle, Chg , Ala(cBu), Gly(cPent), Hle, Nva, Phe, Hph, Gly, Aib, Lys(Boc), Ala, D-MeVal, Asn(Trt), Ser(tBu), and bAla(2-Me2).

[0177] In one embodiment, the peptide supported on the resin for solid-phase synthesis before the first extension reaction in the solid-phase method can be a dipeptide represented by the following formula (1): (In the formula, L １ is a single bond or -CHM １ -, -CH ２ CHM １ -, -CHM １ CH ２ -, -(CH ２ ) ｎ S (CH ２ ) ｍ -, -(CH ２ ) ｎ S(O)(CH ２ ) ｍ - or - (CH ２ ) ｎ S (O) ２ (CH ２ ) ｍ -, where n and m are each independently 1 or 2; R １ is hydrogen, C １ -C ６ Alkyl, C ２ -C ６ Alkenyl, C２ -C ６ Alkynyl, C １ -C ６ Alkoxy C １ -C ６ Alkyl, C ７ -C １４ aralkyl, or aminocarbonyl (wherein the amino is —NH ２ , Mono C １ -C ６ Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino), each of which is selected from halogen, oxo, hydroxy, C １ -C ６ alkyl, 4- to 7-membered heterocyclyl, aminocarbonyl (wherein the amino is -NH ２ , Mono C １ -C ６ Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino) and C １ -C ６ alkylsulfonyl, or R １ is a peptide chain containing 1 to 4 amino acid residues, or R １ and P １ is R １ and the carbon atom to which P is bonded. １ together with the nitrogen atom to which R is attached to form a 4- to 7-membered saturated heterocyclic ring, or １ and Q １ together with the carbon atoms to which they are attached form a 3- to 8-membered alicyclic ring or a 4- to 7-membered saturated heterocyclic ring, or R １ and M １ is R １ and the carbon atom to which M is bonded. １ together with the carbon atom to which R is attached form a 3- to 8-membered alicyclic ring, １ and P １ forms a 4- to 7-membered saturated heterocyclic ring, １ is hydrogen or C １ -C ６alkyl, and １ -C ６ Alkyl is substituted with halogen, hydroxy, C １ -C ６ Alkoxy, amino (the amino is —NH ２ , Mono C １ -C ６ Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino, each of which may be substituted with halogen), and aminocarbonyl (the amino is —NH ２ , Mono C １ -C ６ Alkylamino, DiC １ -C ６ R is optionally substituted with one or more groups independently selected from the group consisting of alkylamino, 4- to 8-membered cyclic amino, １ and Q １ Q forms a 3- to 8-membered alicyclic ring or a 4- to 7-membered saturated heterocyclic ring, １ is hydrogen or C １ -C ６ alkyl, R １ and M １ forms a 3- to 8-membered alicyclic ring, M １ is hydrogen, and L ２ is a single bond or -CH ２ - and R ２ is hydrogen, C １ -C ６ Alkyl, C ２ -C ６ Alkynyl, C １ -C ６ Alkoxy C １ -C ６ Alkyl, C ３ -C ８ Cycloalkyl, C ３ -C ８ Cycloalkyl C １ -C ６ Alkyl, C ３ -C ８ Cycloalkoxy C １ -C ６ Alkyl, or C ７-C １４ and aralkyl, each of which is selected from halogen, hydroxy, amino (wherein the amino is -NH ２ , protected amino, mono C １ -C ６ Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino, each of which may be substituted with halogen), aminocarbonyl (the amino is —NH ２ , protected amino, mono C １ -C ６ Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino), and C １ -C ６ alkylsulfonyl; or R ２ and P ２ is R ２ and the carbon atom to which P is bonded. ２ together with the nitrogen atom to which R is attached to form a 4- to 7-membered saturated heterocyclic ring, or ２ and Q ２ together with the carbon atoms to which they are attached form a 3- to 8-membered alicyclic ring or a 4- to 7-membered saturated heterocyclic ring, or R ２ and P ２ forms a 4- to 7-membered saturated heterocyclic ring, ２ is hydrogen or C １ -C ６ alkyl, and １ -C ６ Alkyl is substituted with halogen, hydroxy, C １ -C ６ Alkoxy, amino (the amino is —NH ２ , Mono C １ -C ６ Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino, each of which may be substituted with halogen), and aminocarbonyl (the amino is —NH ２ , Mono C １ -C６ Alkylamino, DiC １ -C ６ R is optionally substituted with one or more groups independently selected from the group consisting of alkylamino, 4- to 8-membered cyclic amino, ２ and Q ２ Q forms a 3- to 8-membered alicyclic ring or a 4- to 7-membered saturated heterocyclic ring, ２ is hydrogen or C １ -C ６ alkyl, * represents a binding site with a resin for solid phase synthesis, PG is a protecting group for an amino group, provided that P １ and P ２ cannot both be hydrogen.)

[0178] The dipeptide represented by the following formula (1) is preferably a dipeptide represented by the following formula (2). (In the formula, R １ is hydrogen, C １ -C ６ Alkyl, haloC １ -C ６ Alkyl, C ２ -C ６ Alkenyl, C ２ -C ６ Alkynyl, C １ -C ６ Alkoxy C １ -C ６ Alkyl (the C １ -C ６ Alkoxy C １ -C ６ Alkyl is hydroxy, or aminocarbonyl (wherein the amino is -NH ２ , Mono C １ -C ６ Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino), C optionally substituted by one or more halogens ７ -C １４ aralkyl, or aminocarbonyl (wherein the amino is —NH ２ , Mono C １ -C ６Alkylamino, DiC １ -C ６ alkylamino, or 4- to 8-membered cyclic amino, wherein the cyclic amino is selected from the group consisting of one or more halogens, one or more oxo, one or more C １ -C ６ alkyl, or 4- to 7-membered heterocyclyl), or R １ and M １ is R １ and the carbon atom to which M is bonded. １ together with the carbon atom to which R is attached to form a 3- to 8-membered alicyclic ring, or １ and P １ Is, P １ and the nitrogen atom to which R １ together with the carbon atom to which R is attached form a 4- to 7-membered saturated heterocyclic ring, １ and M １ forms a 3- to 8-membered alicyclic ring, M １ is hydrogen, and R １ and P １ forms a 4- to 7-membered saturated heterocyclic ring, １ is hydrogen or C １ -C ６ alkyl, R ２ is C １ -C ６ Alkyl, haloC １ -C ６ Alkyl, hydroxy C １ -C ６ Alkyl, C １ -C ６ Alkylsulfonyl C １ -C ６ Alkyl, C ２ -C ６ alkynyl, C optionally substituted by one or more halogens １ -C ６ Alkoxy C １ -C ６ Alkyl, C ３ -C ８ Cycloalkyl, C ３ -C ８ Cycloalkyl C １ -C６ Alkyl, C ３ -C ８ Cycloalkoxy C １ -C ６ Alkyl, or C ７ -C １４ aralkyl, or R ２ and P ２ Is, P ２ and the nitrogen atom to which R ２ together with the carbon atom to which R is attached form a 4- to 7-membered saturated heterocyclic ring, ２ and P ２ forms a 4- to 7-membered saturated heterocyclic ring, ２ is hydrogen or C １ -C ６ is alkyl, and Q ２ is hydrogen, * represents a binding site with a resin for solid phase synthesis, PG is a protecting group for an amino group, and １ and P ２ cannot both be hydrogen.)

[0179] In one embodiment, L in formula (1) or formula (2) １ , P １ , Q １ , and R １ is L in the formula (A). １ , P １ , Q １ , and R １ and L ２ , P ２ , Q ２ , and R ２ is L in the formula (B). ２ , P ２ , Q ２ , and R ２ In the formula (1) or (2), P １ and P ２ It is preferred that neither of

[0180] PG in formula (1) or (2) is a protecting group for an amino group.

[0181] In certain embodiments, when the starting peptide is a dipeptide, non-limiting examples of the dipeptide include Fmoc-MeVal-MeAsp-pip, Fmoc-MeIle-MeAsp-pip, Fmoc-MeGly(cPent)-MeAsp-pip, Fmoc-MeChg-MeAsp-pip, Fmoc-MeLeu-MeAsp-pip, Fmoc-MeGly(cPent)-MeAsp-NMe2, Fmoc-MeLeu-MeAsp-NMe2, Fmoc-MeVal-D-3-MeAbu-OH, Fmoc-MeChg-D-3-MeAbu-OH, Fmoc-MeVal-MeGly-OH, Fmoc-MeVal-Asp-NMe2, Fmoc-Gly-MeAsp-NMe2, Fmoc-Aib-MeAsp-NMe2, and Fmoc-D-MeVal. -MeAsp-NMe2, Fmoc-MeVal-D-MeAsp-NMe2, Fmoc-bAla(2-Me2)-MeAsp-NMe2, Fmoc-bAla(2-Me2)-D-3-MeA bu-OH, Fmoc-MeLeu-MeVal-OH, Fmoc-MeVal-Pro-OH, Fmoc-Phe-Pro-OH, Fmoc-Lys(Boc)-Pro-OH, Fmoc-Me Examples include Leu-Aib-OH, Fmoc-MeVal-Gly-OH, Fmoc-Ala-Ala-OH, Fmoc-Gly-Tyr(tBu)-OH, Fmoc-Phe-Gly-OH, Fmoc-Asn(Trt)-Gly-OH, Fmoc-MeGly(cPent)-MeAsp-mor, Fmoc-Gly-Val-OH, and Fmoc-Ser(tBu)-Gly-OH.

[0182] In certain embodiments, when the starting peptide is a tripeptide, non-limiting examples of the tripeptide include Ala-Ala-Pro, Gly-Gly-Gly, Ala-Gly-Asp, or N-substituted or derivatives thereof. Each amino acid residue constituting the tripeptide may be N-substituted or derivatized. In this manner, premature cleavage can be suppressed by using a solid-phase synthesis resin supported with a tripeptide. When extending a sequence of consecutive amino acids of the same species, the reaction process can be shortened by performing a single extension using a peptide instead of multiple amino acid extension reactions.

[0183] The "peptide compound" produced by the solid-phase method of the present invention is a linear peptide compound that, in addition to the above-mentioned total number of natural and unnatural amino acid residues, contains at least one, preferably at least two N-substituted amino acid residues (specifically, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, or 30, preferably 5, 6, or 7, with preferred ranges being 2 to 30, 3 to 30, 6 to 20, 7 to 19, 7 to 18, 7 to 17, 7 to 16, 7 to 15, 8 to 14, or 9 to 13), and at least one non-N-substituted amino acid residue. The proportion of N-substituted amino acid residues contained in such a peptide compound is, for example, 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, or 80% or more of the total number of amino acid residues constituting the peptide compound. The N-substituted amino acid residue of the present invention may be a non-naturally occurring N-substituted amino acid residue other than proline. The peptide compound of the present invention may contain a repeat sequence, for example, a repeat sequence of 2, 3, 4, or 5 amino acid residues, but the number of repeats is preferably 2 or less or 3 or less. It is more preferable that the peptide compound of the present invention does not contain such a repeat sequence.

[0184] In one embodiment, the "solid-phase synthesis resin" used in the present invention is not particularly limited as long as it can be used in the synthesis of peptide compounds by solid-phase synthesis. Specific examples of such solid-phase synthesis resins include CTC resin, Sieber resin, Wang resin, SASRIN resin, trityl chloride resin (Trt resin), 4-methyltrityl chloride resin (Mtt resin), and 4-methoxytrityl chloride resin (Mmt), which are removable under acidic conditions. The resin can be appropriately selected depending on the functional group of the amino acid used. For example, when a carboxylic acid (main-chain carboxylic acid or side-chain carboxylic acid, such as Asp or Glu) or a hydroxy group on an aromatic ring (phenol group, such as Tyr) is used as the functional group of the amino acid, it is preferable to use trityl chloride resin (Trt resin) or 2-chlorotrityl chloride resin (CTC resin). When an aliphatic hydroxy group (an aliphatic alcohol group typified by Ser or Thr) is used as the functional group on the amino acid side, it is preferable to use trityl chloride resin (Trt resin), 2-chlorotrityl chloride resin (CTC resin), or 4-methyltrityl chloride resin (Mtt resin). Note that, in this specification, resin may also be referred to as "resin." The solid-phase synthesis resin can be linked to an amino acid at any position in the peptide, not limited to the C-terminal amino acid. It is preferable that the carboxyl group of the C-terminal amino acid is linked to the solid-phase synthesis resin, and this carboxyl group may be a carboxyl group in the main chain or a carboxyl group in the side chain. When a resin having a trityl skeleton in the linker moiety, specifically a CTC resin, Trt resin, Mtt resin, or Mmt resin, is used as the solid-phase synthesis resin, premature cleavage is likely to occur, making the method of the present invention particularly advantageous.

[0185] There are no particular limitations on the type of polymer that constitutes the resin. In the case of a resin made of polystyrene, either 100-200 mesh or 200-400 mesh may be used. There are also no particular limitations on the cross-linking rate, but 1% DVB (divinylbenzene) cross-linking is preferred. Examples of the type of polymer that constitutes the resin include Tentagel and Chemmatrix.

[0186] In one embodiment, the present invention may include a step of supporting a peptide on a resin for solid-phase synthesis. The reaction conditions for this step may be any reaction conditions known in the art and are not particularly limited. For example, it is preferable to apply the reaction conditions described in WO2013 / 100132 or WO2018 / 225864 or the reaction conditions described in the Solid Phase Synthesis Handbook published by Merck Ltd. on May 1, 2002.

[0187] Specific examples of the process for supporting a peptide on a resin for solid-phase synthesis include, but are not limited to, the following: The resin is swollen with an appropriate solvent, and a solution of a peptide whose amino group has been protected with a protecting group (protected peptide) is allowed to act on the resin for solid-phase synthesis in the presence of a base, thereby supporting the protected peptide on the resin. Examples of solvents used for swelling and for preparing the peptide solution include halogenated solvents such as DCM (dichloromethane), chloroform, and DCE (1,2-dichloroethane), ether solvents such as THF (tetrahydrofuran), 2-methyltetrahydrofuran, 4-methyltetrahydropyran, dioxane, DME (1,2-dimethoxyethane), TBME (t-butyl methyl ether), CPME (cyclopentyl methyl ether), and isosorbide dimethyl ether, ketone solvents such as acetone, MEK (methyl ethyl ketone), 4-methyl-2-pentanone, and cyclopentanone, urea solvents such as TMU (N,N,N',N'-tetramethylurea), DMI (1,3-dimethyl-2-imidazolidinone), and DMPU (N,N'-dimethylpropyleneurea), and DMF (N,N-dimethylpropyleneurea). Examples of suitable solvents include amide solvents such as dimethylformamide (DMSO), N,N-dimethylacetamide (DMA), N-formylmorpholine (NFM), N-methyl-2-pyrrolidone (NMP), and N-butyl-2-pyrrolidone (NBP), sulfoxide solvents such as dimethyl sulfoxide (DMSO), sulfone solvents such as sulfolane, ester solvents such as ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, and γ-valerolactone (GVL), aromatic solvents such as anisole, toluene, α,α,α-trifluorotoluene, 1,2-dichlorobenzene, and benzene, and carbonate solvents such as dimethyl carbonate, diethyl carbonate, ethylene carbonate, and propylene carbonate. In addition to these, solvents such as acetonitrile, methanol, ethylene glycol, water, silane, and limonene can also be used. Furthermore, a mixture of multiple solvents in any ratio can also be used.Examples of the amino-protecting group that can be used include carbamate-type protecting groups such as Fmoc, Boc, Alloc, Cbz, and Teoc, amide-type protecting groups such as trifluoroacetyl, arylsulfonamide-type protecting groups such as benzenesulfonyl, tosyl, nosyl, and dinitronosyl, alkylamine-type protecting groups such as t-Bu, trityl, and cumyl, and imide-type protecting groups such as benzylidene, 4-methoxybenzylidene, and diphenylmethylidene. Examples of the base that can be used include tertiary amine bases such as triethylamine, DIPEA (N,N-diisopropylethylamine), NMM (N-methylmorpholine), and DABCO (1,4-diazabicyclo[2.2.2]-octane), and pyridine-based bases such as pyridine, lutidine, collidine, and DMAP (4-dimethylaminopyridine).

[0188] In one embodiment, the present invention further comprises a step of extending the peptide supported on the solid-phase synthesis resin by one or more amino acids. This step allows for the production of a peptide compound having a desired amino acid sequence. This step can be performed using methods known in the art, such as those described in WO2013 / 100132, WO2018 / 225851, and WO2018 / 225864, or the Solid Phase Synthesis Handbook published by Merck Ltd. on May 1, 2002.

[0189] Specific examples of the step of extending one or more amino acid residues on a peptide supported on a solid-phase synthesis resin include, but are not limited to, the following: a step of deprotecting the protecting group at the N-terminus of the peptide supported on a solid-phase synthesis resin, and a step of allowing an amino acid residue whose amino group is protected with a protecting group (protected amino acid residue) and a condensation reagent to act on the peptide in a solvent in the presence or absence of a base; by repeating these two steps, multiple amino acid residues can be extended. Examples of N-terminal protecting groups that can be used include carbamate-type protecting groups such as Fmoc, Boc, Alloc, Cbz, and Teoc groups, amide-type protecting groups such as trifluoroacetyl, arylsulfonamide-type protecting groups such as benzenesulfonyl, tosyl, nosyl, and dinitronosyl groups, alkylamine-type protecting groups such as t-Bu, trityl, and cumyl groups, and imide-type protecting groups such as benzylidene, 4-methoxybenzylidene, and diphenylmethylidene groups, with the Fmoc group being preferred. When the Fmoc group is used as the protecting group, piperidine, DBU (1,8-diazabicyclo[5.4.0]-7-undecene), DBN (1,5-diazabicyclo[4.3.0]-5-nonene), or the like can be used for deprotection.Condensation reagents include carbodiimide condensation agents such as DCC (N,N'-dicyclohexylcarbodiimide), DIC (N,N'-diisopropylcarbodiimide), and EDCI (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride), and activators such as HOAt (1-hydroxy-7-azabenzotriazole), HOBt (1-hydroxybenzotriazole), HOOBt (3,4-dihydro-3-hydroxy-4-oxo-1,2,3-benzotriazine), and oxyma (ethyl cyano(hydroxyimino)acetate). , HATU (O-(7-aza-1H-benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate), HBTU (O-(1H-benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate), HCTU (O-(6-chloro-1H-benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate), COMU ((1-cyano-2-ethoxy-2-oxoethylideneaminooxy)dimethylaminomorpholinocarbenium uronium salt condensing agents such as PyAOP ((7-azabenzotriazol-1-yloxy)trispyrrolizinophosphonium hexafluorophosphate), PyBOP (1H-benzotriazol-1-yloxy-tri(pyrrolizino)phosphonium hexafluorophosphate), PyOxim ([ethylcyano(hydroxyimino)acetato-O. ２]tri-1-pyrrolidinylphosphonium hexafluorophosphate), and formamidinium salt-based condensing agents such as 1-chloro-N,N-2-trimethyl-1-propenylamine (Ghosez reagent), TCFH (chloro-N,N,N',N'-tetramethylformamidinium hexafluorophosphate), PyCIU (N,N,N',N'-bis(tetramethylene)chloroformamidinium hexafluorophosphate), BTFFH (fluoro-N,N,N',N'-bis(tetramethylene)formamidinium hexafluorophosphate), and TFFH (fluoro-N,N,N',N'-tetramethylamidinium hexafluorophosphate), and the like can be used. Examples of the base that can be used include tertiary amine bases such as triethylamine, DIPEA (N,N-diisopropylethylamine), NMM (N-methylmorpholine), and DABCO (1,4-diazabicyclo[2.2.2]-octane), and pyridine-based bases such as pyridine, lutidine, collidine, and DMAP (4-dimethylaminopyridine).Examples of the solvent include halogen-based solvents such as DCM (dichloromethane), chloroform, and DCE (1,2-dichloroethane); ether-based solvents such as THF (tetrahydrofuran), 4-methyltetrahydrofuran, 4-methyltetrahydropyran, dioxane, DME (1,2-dimethoxyethane), TBME (t-butyl methyl ether), CPME (cyclopentyl methyl ether), and isosorbide dimethyl ether; ketone-based solvents such as acetone, MEK (methyl ethyl ketone), 4-methyl-2-pentanone, and cyclopentanone; urea-based solvents such as TMU (N,N,N',N'-tetramethylurea), DMI (1,3-dimethyl-2-imidazolidinone), and DMPU (N,N'-dimethylpropylene urea); and dimethylformamide (DMF) and DMA (N Examples of suitable solvents include amide solvents such as dimethyl acetamide (DMSO), NFM (N-formylmorpholine), NMP (N-methyl-2-pyrrolidone), and NBP (N-butyl-2-pyrrolidone), sulfoxide solvents such as DMSO (dimethyl sulfoxide), sulfone solvents such as sulfolane, ester solvents such as ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, and GVL (γ-valerolactone), aromatic solvents such as anisole, toluene, α,α,α-trifluorotoluene, 1,2-dichlorobenzene, and benzene, and carbonate solvents such as dimethyl carbonate, diethyl carbonate, ethylene carbonate, and propylene carbonate. In addition to these, solvents such as acetonitrile, methanol, ethylene glycol, water, silane, and limonene can also be used. Furthermore, a mixture of a plurality of these solvents in any ratio can also be used.

[0190] In one aspect, the present invention also relates to a method for producing a cyclic peptide compound, further comprising the steps of obtaining a linear peptide compound, a salt thereof, or a solvate thereof produced by the above-described method of the present invention, removing the solid-phase synthesis resin, and cyclizing the C-terminal group and the N-terminal group to form a cyclic moiety.

[0191] Methods known in the art can be used for both the step of removing the peptide compound from the solid-phase synthesis resin and the step of cyclizing the C-terminal group and the N-terminal group of the peptide compound to form a cyclic moiety. For example, the methods described in WO2013 / 100132, WO2018 / 225851, and WO2018 / 225864, and the method described in the Solid Phase Synthesis Handbook published by Merck Ltd. on May 1, 2002, can be applied.

[0192] Specific examples of steps for removing a peptide compound from a solid-phase synthesis resin include, but are not limited to, the following: After the peptide chain has been elongated until the desired amino acid sequence is obtained, the solid-phase synthesis resin is swelled with an appropriate solvent, and then treated with an acidic solution, thereby removing the peptide compound from the resin. Examples of the solvent used for swelling include halogen-based solvents such as DCM (dichloromethane), chloroform, and DCE (1,2-dichloroethane); ether-based solvents such as THF (tetrahydrofuran), 4-methyltetrahydrofuran, 4-methyltetrahydropyran, dioxane, DME (1,2-dimethoxyethane), TBME (t-butyl methyl ether), CPME (cyclopentyl methyl ether), and isosorbide dimethyl ether; ketone-based solvents such as acetone, MEK (methyl ethyl ketone), 4-methyl-2-pentanone, and cyclopentanone; urea-based solvents such as TMU (N,N,N',N'-tetramethylurea), DMI (1,3-dimethyl-2-imidazolidinone), and DMPU (N,N'-dimethylpropylene urea); DMF (N,N-dimethylformamide), DM Examples of suitable solvents include amide solvents such as N,N-dimethylacetamide (NMP), N-formylmorpholine (NFM), N-methyl-2-pyrrolidone (NMP), and N-butyl-2-pyrrolidone (NBP), sulfoxide solvents such as dimethyl sulfoxide (DMSO), sulfone solvents such as sulfolane, ester solvents such as ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, and γ-valerolactone (GVL), aromatic solvents such as anisole, toluene, α,α,α-trifluorotoluene, 1,2-dichlorobenzene, and benzene, and carbonate solvents such as dimethyl carbonate, diethyl carbonate, ethylene carbonate, and propylene carbonate. Other solvents that can be used include acetonitrile, methanol, ethylene glycol, water, silane, and limonene. Furthermore, a mixture of a plurality of these solvents in any ratio can also be used. The acidic solution may be a fluoroalcohol such as TFE (2,2,2-trifluoroethanol) or HFIP (1,1,1,3,3,3-hexafluoroisopropyl alcohol), a carboxylic acid such as TFA (trifluoroacetic acid), or hydrochloric acid.

[0193] In one embodiment, the "solid-phase synthesis resin" used in the present invention is preferably one that can cleave a peptide compound having a target amino acid sequence synthesized by a solid-phase method, for example, under mild acidic conditions that do not remove the protecting groups on the side chains of the amino acids that make up the peptide compound. Specific examples of protecting groups on the amino acid side chains include Boc, Trt, THP, and tBu. Examples of amino acids having protecting groups on their side chains include Tyr(tBu), Ser(tBu), Thr(tBu), Asp(tBu), Glu(tBu), Trp(Boc), Lys(Boc), His(Boc), Ser(Trt), Thr(Trt), Trp(Trt), Lys(Trt), His(Trt), Asn(Trt), Gln(Trt), Ser(THP), or Thr(THP), as well as N-alkylated versions thereof, such as N-methylated versions.

[0194] In one embodiment, the "solid-phase synthesis resin" used in the present invention is preferably one that allows the supported peptide compound to be cleaved under mild acidic conditions. For example, a resin having a trityl skeleton at the linker moiety, specifically, a CTC resin, a Trt resin, an Mtt resin, or an Mmt resin, or a resin having a diphenylmethyl skeleton at the linker moiety, specifically, a Sieber resin, is preferred. More preferred examples of such solid-phase synthesis resins include a CTC resin or a Sieber resin, and most preferred examples include a CTC resin.

[0195] In some embodiments, the mild acidic conditions may include temperature conditions. The "resin for solid phase synthesis" used in the present invention is preferably one that can be removed under mild acidic conditions at a temperature around room temperature, for example, at a temperature of room temperature ± 10°C.

[0196] In certain embodiments, the mildly acidic conditions are acidic conditions with a pH of 2 or higher. Furthermore, in certain embodiments, the mildly acidic conditions can include conditions using a dilute acid solution. As used herein, a dilute acid solution refers to an acid diluted with a non-acidic solvent, and can be prepared by mixing an acid with a non-acidic solvent. Examples of acids used in the dilute solution include acids with a pKa in water of −1 or higher, 1 or higher, 2 or higher, 3 or higher, 4 or higher, 5 or higher, 6 or higher, 7 or higher, 8 or higher, 9 or higher, 10 or higher, 11 or higher, or 12 or higher. Specific examples include TFA, 2,2,2-trifluoroethanol, 1,1,1,3,3,3-hexafluoroisopropyl alcohol, trichloroacetic acid, acetic acid, formic acid, oxalic acid, or a mixture thereof. Such acids are preferably TFA, 2,2,2-trifluoroethanol, 1,1,1,3,3,3-hexafluoroisopropyl alcohol, acetic acid, or a mixture thereof, and more preferably TFA. The volume % of the acid in the dilute solution may be 60% or less, 50% or less, 40% or less, 30% or less, 20% or less, 10% or less, 5% or less, 4% or less, 3% or less, 2% or less, or 1% or less, preferably 20% or less, 10% or less, 5% or less, 4% or less, 3% or less, 2% or less, or 1% or less, more preferably 10% or less, 5% or less, 4% or less, 3% or less, 2% or less, or 1% or less. The non-acidic solvent used in the dilute acid solution is preferably DCM, dichloroethane, water, or 2-MeTHF, or a mixed solvent thereof, more preferably DCM. Specific examples of such dilute acid solutions include a DCM solution containing 20% ​​or less by volume of TFA, a DCM solution containing 10% or less by volume of TFA, a DCM solution containing 5% or less by volume of TFA, a DCM solution containing 1% or less by volume of TFA, a DCM solution containing 20% ​​or less of acetic acid and 20% or less of 2,2,2-trifluoroethanol, and a DCM solution containing 20% ​​or less of 1,1,1,3,3,3-hexafluoroisopropyl alcohol.

[0197] Specific examples of the process for forming a cyclic moiety by cyclizing the C-terminal group and the N-terminal group of a peptide compound include, but are not limited to, the following: A condensation reagent is allowed to act on a linear peptide compound dissolved in an appropriate solvent in the presence or absence of a base, thereby cyclizing the C-terminal group and the N-terminal group of the peptide compound to form a cyclic moiety. Examples of the solvent include halogen-based solvents such as DCM (dichloromethane), chloroform, and DCE (1,2-dichloroethane); ether-based solvents such as THF (tetrahydrofuran), 4-methyltetrahydrofuran, 4-methyltetrahydropyran, dioxane, DME (1,2-dimethoxyethane), TBME (t-butyl methyl ether), CPME (cyclopentyl methyl ether), and isosorbide dimethyl ether; ketone-based solvents such as acetone, MEK (methyl ethyl ketone), 4-methyl-2-pentanone, and cyclopentanone; urea-based solvents such as TMU (N,N,N',N'-tetramethylurea), DMI (1,3-dimethyl-2-imidazolidinone), and DMPU (N,N'-dimethylpropylene urea); and N,N-dimethylformamide (DMF). Examples of suitable solvents include amide solvents such as N,N-dimethylacetamide (DMA), NFM (N-formylmorpholine), NMP (N-methyl-2-pyrrolidone), and NBP (N-butyl-2-pyrrolidone); sulfoxide solvents such as DMSO (dimethyl sulfoxide); sulfone solvents such as sulfolane; ester solvents such as ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, and GVL (γ-valerolactone); aromatic solvents such as anisole, toluene, α,α,α-trifluorotoluene, 1,2-dichlorobenzene, and benzene; and carbonate solvents such as dimethyl carbonate, diethyl carbonate, ethylene carbonate, and propylene carbonate. In addition to these, solvents such as acetonitrile, silane, and limonene can also be used. Furthermore, a mixture of a plurality of these solvents in any ratio can also be used.Condensation reagents include carbodiimide condensing agents such as DCC (N,N'-dicyclohexylcarbodiimide), DIC (N,N'-diisopropylcarbodiimide), and EDCI (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride), HOAt (1-hydroxy-7-azabenzotriazole), Combination with activators such as HOBt (1-hydroxybenzotriazole), HOOBt (3,4-dihydro-3-hydroxy-4-oxo-1,2,3-benzotriazine), oxyma (ethyl cyano(hydroxyimino)acetate), HATU (O-(7-aza-1H-benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate), HBTU (O-(1H-benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate), HCTU (O-(6-chloro-1H-benzotriazole- uronium salt-based condensing agents such as (1-cyano-2-ethoxy-2-oxoethylideneaminooxy)dimethylaminomorpholinocarbenium hexafluorophosphate), COMU ((1-cyano-2-ethoxy-2-oxoethylideneaminooxy)dimethylaminomorpholinocarbenium hexafluorophosphate), PyAOP ((7-azabenzotriazol-1-yloxy)trispyrrolidinophosphonium hexafluorophosphate), PyBOP (1H-benzotriazol-1-yloxy-tri(pyrrolidino)phosphonium hexafluorophosphate), PyOxim ([ethylcyano(hydroxyimino)acetato-O,N,N',N'-tetramethyluronium hexafluorophosphate]), ２]tri-1-pyrrolidinylphosphonium hexafluorophosphate), and formamidinium salt-based condensing agents such as 1-chloro-N,N-2-trimethyl-1-propenylamine (Ghosez reagent), TCFH (chloro-N,N,N',N'-tetramethylformamidinium hexafluorophosphate), PyCIU (N,N,N',N'-bis(tetramethylene)chloroformamidinium hexafluorophosphate), BTFFH (fluoro-N,N,N',N'-bis(tetramethylene)formamidinium hexafluorophosphate), and TFFH (fluoro-N,N,N',N'-tetramethylamidinium hexafluorophosphate), and the like can be used. Examples of the base that can be used include tertiary amine bases such as triethylamine, DIPEA (N,N-diisopropylethylamine), NMM (N-methylmorpholine), and DABCO (1,4-diazabicyclo[2.2.2]-octane), and pyridine-based bases such as pyridine, lutidine, collidine, and DMAP (4-dimethylaminopyridine).

[0198] In one embodiment, the number of N-substituted amino acids contained in the peptide portion of the cyclic peptide compound is preferably 2 or more or 3 or more, more preferably 4 or more, 5 or more, or 6 or more, even more preferably 7 or more, and particularly preferably 8 or more, and preferred examples are 20 or less, 15 or less, 14 or less, 13 or less, 12 or less, 10 or less, and 9 or less. Examples of the number of N-substituted amino acids contained in the cyclic peptide compound herein are 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, and 80% or more of the number of amino acids constituting the cyclic portion.

[0199] In one aspect, the present invention relates to a method for producing a peptide compound containing at least one N-substituted amino acid residue, a salt thereof, or a solvate thereof by a solid-phase synthesis method, which method improves the recovery rate of the peptide compound compared to elongating amino acids one residue at a time, characterized in that the peptide is supported on a solid-phase synthesis resin before the first elongation reaction. That is, the present invention relates to a method for obtaining a peptide compound having a target amino acid sequence by elongating a peptide chain by a solid-phase synthesis method using a peptide (preferably a dipeptide or tripeptide) as a starting material, and the recovery rate of the target peptide compound can be improved by, for example, 5% or more, 10% or more, 20% or more, 30% or more, 40% or more, or 50% or more compared to producing a peptide compound having the same amino acid sequence by a solid-phase synthesis method using amino acids as a starting material.

[0200] In one aspect, the present invention relates to a method for suppressing the production of a peptide compound containing at least one N-substituted amino acid residue, a salt thereof, or a solvate thereof by solid-phase synthesis, characterized in that the peptide is supported on a solid-phase synthesis resin before the first elongation reaction, thereby suppressing the production of impurities compared to when amino acids are elongated one residue at a time. That is, the present invention relates to a method for obtaining a peptide compound having a desired amino acid sequence by elongating a peptide chain by solid-phase synthesis using a peptide (preferably a dipeptide or tripeptide) as a starting material, and the production of impurities (e.g., epimers, over-elongated products, and amino acid deletion products) can be suppressed by, for example, 0.5% or more, 1% or more, 5% or more, 10% or more, 20% or more, 30% or more, or 40% or more compared to when a peptide compound having the same amino acid sequence is produced by solid-phase synthesis using amino acids as starting materials.

[0201] In one aspect, the present invention relates to a method for suppressing premature cleavage compared to elongating amino acids one by one in the production of a peptide compound containing at least one N-substituted amino acid residue, a salt thereof, or a solvate thereof by a solid-phase synthesis method, characterized in that the peptide is supported on a solid-phase synthesis resin before the first elongation reaction. That is, the present invention relates to a method for obtaining a peptide compound having a desired amino acid sequence by elongating a peptide chain by a solid-phase synthesis method using a peptide (preferably a dipeptide or tripeptide) as a starting material, and the premature cleavage can be significantly suppressed, for example, by 5% or more, 10% or more, 20% or more, 30% or more, 40% or more, or 50% or more, compared to the production of a peptide compound having the same amino acid sequence by a solid-phase synthesis method using amino acids as a starting material.

[0202] The compounds of the present invention, salts thereof, or solvates thereof include all stereoisomers (e.g., enantiomers, diastereomers (including cis and trans geometric isomers)), racemates of such isomers, and other mixtures thereof. For example, the compounds of the present invention may have one or more asymmetric centers, and the present invention includes racemic mixtures, diastereomeric mixtures, and enantiomers of such compounds.

[0203] When the compound according to the present invention is obtained as a free form, the compound can be converted into a salt which the compound may form, or a hydrate or solvate thereof, in a conventional manner.

[0204] Furthermore, when the compound according to the present invention is obtained as a salt, hydrate, or solvate of the compound, the compound can be converted into its free form by a conventional method.

[0205] All prior art documents cited in this specification are hereby incorporated by reference.

[0206] The present invention is further illustrated, but not limited, in the following examples. All starting materials and reagents were obtained from commercial suppliers or synthesized using known methods.

[0207] The LCMS analysis conditions are listed in the table below.

[0208] Example 1 Synthesis of Amino Acids and Other Compounds Used in Peptide Synthesis Using a Peptide Synthesizer For the peptide synthesis described herein, the amino acids or peptides listed in Tables 2, 3, 4, and 5, and the resins carrying them, were used.

[0209] Example 1-1. Fmoc-amino acids and peptides used as purchased Fmoc-amino acids and peptides listed in Table 2 were purchased from commercial suppliers.

[0210]

[0211] Example 1-2. Synthesis of Fmoc-dipeptides The Fmoc-dipeptides shown in Table 3 were synthesized according to the scheme shown below.

[0212]

[0213] Synthesis of compound aa2-001, Fmoc-MeVal-MeAsp-pip

[0214] Synthesis of compound aa2-001-a, (3S)-3-[[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-3-methylbutanoyl]-methylamino]-4-oxo-4-piperidin-1-ylbutanoate prop-2-enyl (Fmoc-MeVal-MeAsp(OAl)-pip) The starting material, Fmoc-MeAsp(OAl)-pip, was synthesized according to the method described in WO2018 / 225864. Under a nitrogen atmosphere, Fmoc-MeVal-OH (4.25 g, 12.0 mmol), EDCI (3.23 g, 16.8 mmol), oxyma (2.05 g, 14.4 mmol), and DMF (40 mL) were added to a reaction vessel. The reaction mixture was stirred for 30 min to obtain an activated ester solution of Fmoc-MeVal-OH. Under a nitrogen atmosphere, Fmoc-MeAsp(OAl)-pip (5.00 g, 10.5 mmol) and DMF (40 mL) were added to the reaction vessel, followed by the addition of DBU (1.60 g, 10.5 mmol) at room temperature. After stirring the reaction mixture for 5 min, pyridine hydrochloride (1.33 g, 11.5 mmol) was added at room temperature under a nitrogen atmosphere. After stirring the reaction mixture for 10 minutes, the activated ester solution of Fmoc-MeVal-OH prepared above and DIPEA (1.49 g, 11.5 mmol) were added under a nitrogen stream at room temperature, and the reaction mixture was stirred for 5 hours. The reaction mixture was concentrated under reduced pressure, and the resulting residue was purified by reverse-phase silica gel column chromatography (water / acetonitrile = 95 / 5 → 20 / 80) to obtain compound aa2-001-a as a pink solid (3.03 g, 48% yield). LCMS(ESI) m / z = 590.6 (M+H) + Retention time: 1.06 minutes (Analysis conditions SQDFA05)

[0215] Synthesis of compound aa2-001, (3S)-3-[[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-3-methylbutanoyl]-methylamino]-4-oxo-4-piperidin-1-ylbutanoic acid (Fmoc-MeVal-MeAsp-pip) Compound aa2-001-a (1.18 g, 2.00 mmol) and tetrakistriphenylphosphine palladium (23.1 mg, 0.020 mmol) were added to a reaction vessel under a nitrogen stream, followed by DCM (4.0 mL). Phenylsilane (0.152 g, 1.40 mmol) was added dropwise to the reaction mixture, and the mixture was stirred at room temperature for 30 min. The reaction mixture was diluted with TBME (11.8 mL) and extracted with saturated aqueous sodium bicarbonate / water (1 / 1, 11.8 mL) followed by water (5.9 mL). The combined aqueous layer was acidified to approximately pH 2 with 85% aqueous phosphoric acid (0.700 mL, 10.2 mmol), and the aqueous layer was extracted twice with DCM (11.8 mL). The combined organic layer was washed with saturated aqueous sodium chloride / water (1 / 1, 11.8 mL) and then dried over sodium sulfate. After filtering off the drying agent, the filtrate was concentrated under reduced pressure to obtain 1.06 g (97% yield) of compound aa2-001 as pale brown amorphous crystals. LCMS (ESI) m / z = 550.5 (M+H) + Retention time: 0.93 minutes (Analysis conditions SQDFA05)

[0216] Synthesis of compound aa2-002, Fmoc-MeIle-MeAsp-pip

[0217] Synthesis of compound aa2-002-a, (3S)-3-[[(2S,3S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-3-methylpentanoyl]-methylamino]-4-oxo-4-piperidin-1-ylbutanoate prop-2-enyl (Fmoc-MeIle-MeAsp(OAl)-pip) Using Fmoc-MeAsp(OAl)-pip (10.0 g, 21.0 mmol) and Fmoc-MeIle-OH (6.80 g, 18.5 mmol) as starting materials, compound aa2-002-a was obtained as an orange solid (3.64 g, 29% yield) in the same manner as in the synthesis of compound aa2-001-a. LCMS (ESI) m / z = 604.6 (M+H) + Retention time: 1.10 minutes (Analysis conditions SQDFA05)

[0218] Synthesis of compound aa2-002, (3S)-3-[[(2S,3S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-3-methylpentanoyl]-methylamino]-4-oxo-4-piperidin-1-ylbutanoic acid (Fmoc-MeIle-MeAsp-pip) Using compound aa2-002-a (1.21 g, 2.00 mmol) as the starting material, compound aa2-002 was obtained as pale brown amorphous crystals (1.05 g, 93% yield) in the same manner as compound aa2-001. LCMS (ESI) m / z = 564.7 (M+H) + Retention time: 0.99 minutes (Analysis conditions SQDFA05)

[0219] Synthesis of compound aa2-003, Fmoc-MeGly(cPent)-MeAsp-pip

[0220] Synthesis of compound aa2-003-a, (3S)-3-[[(2S)-2-cyclopentyl-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]acetyl]-methylamino]-4-oxo-4-piperidin-1-ylbutanoate prop-2-enyl (Fmoc-MeGly(cPent)-MeAsp(OAl)-pip) Using the compounds Fmoc-MeAsp(OAl)-pip (10.0 g, 21.0 mmol) and Fmoc-MeGly(cPent)-OH (8.75 g, 23.1 mmol) as starting materials, compound aa2-003-a was obtained as an orange solid (3.49 g, 27% yield) in the same manner as in the synthesis of compound aa2-001-a. LCMS (ESI) m / z = 616.6 (M+H) + Retention time: 1.11 minutes (Analysis conditions SQDFA05)

[0221] Synthesis of compound aa2-003, (3S)-3-[[(2S)-2-cyclopentyl-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]acetyl]-methylamino]-4-oxo-4-piperidin-1-ylbutanoic acid (Fmoc-MeGly(cPent)-MeAsp-pip) Using compound aa2-003-a (1.23 g, 2.00 mmol) as the starting material, compound aa2-003 was obtained as pale brown amorphous crystals (1.12 g, 97% yield) in the same manner as compound aa2-001. LCMS (ESI) m / z = 576.8 (M+H) + Retention time: 0.95 minutes (Analysis conditions SQDFA05)

[0222] Synthesis of compound aa2-004, Fmoc-MeChg-MeAsp-pip

[0223] Synthesis of compound aa2-004-a, (3S)-3-[[(2S)-2-cyclohexyl-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]acetyl]-methylamino]-4-oxo-4-piperidin-1-ylbutanoate prop-2-enyl (Fmoc-MeChg-MeAsp(OAl)-pip) Using Fmoc-MeAsp(OAl)-pip (10.0 g, 21.0 mmol) and Fmoc-MeChg-OH (9.10 g, 23.1 mmol) as starting materials, compound aa2-004-a was obtained as a yellow solid (5.52 g, 42% yield) in the same manner as in the synthesis of compound aa2-001-a. LCMS (ESI) m / z = 630.6 (M+H) + Retention time: 1.13 minutes (Analysis conditions SQDFA05)

[0224] Synthesis of compound aa2-004, (3S)-3-[[(2S)-2-cyclohexyl-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]acetyl]-methylamino]-4-oxo-4-piperidin-1-ylbutanoic acid (Fmoc-MeChg-MeAsp-pip) Using compound aa2-004-a (1.26 g, 2.00 mmol) as the starting material, compound aa2-004 was obtained as pale brown amorphous crystals (0.953 g, 81% yield) in the same manner as compound aa2-001. LCMS (ESI) m / z = 590.6 (M+H) + Retention time: 0.97 minutes (Analysis conditions SQDFA05)

[0225] Synthesis of compound aa2-005, Fmoc-MeLeu-MeAsp-pip

[0226] Synthesis of compound aa2-005-a, (3S)-3-[[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-4-methylpentanoyl]-methylamino]-4-oxo-4-piperidin-1-ylbutanoate prop-2-enyl (Fmoc-MeLeu-MeAsp(OAl)-pip) Using Fmoc-MeAsp(OAl)-pip (8.00 g, 16.79 mmol) and Fmoc-MeLeu-OH (6.48 g, 17.63 mmol) as starting materials, compound aa2-005-a was obtained as yellow amorphous crystals (5.00 g, 49% yield) in the same manner as in the synthesis of compound aa2-001-a. LCMS (ESI) m / z = 604.6 (M+H) + Retention time: 1.10 minutes (Analysis conditions SQDFA05)

[0227] Synthesis of compound aa2-005, (3S)-3-[[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-4-methylpentanoyl]-methylamino]-4-oxo-4-piperidin-1-ylbutanoic acid (Fmoc-MeLeu-MeAsp-pip) Using compound aa2-005-a (1.21 g, 2.00 mmol) as the starting material, compound aa2-005 was obtained as pale brown amorphous crystals (1.09 g, 96% yield) in the same manner as compound aa2-001. LCMS (ESI) m / z = 564.5 (M+H) + Retention time: 0.94 minutes (Analysis conditions SQDFA05)

[0228] Synthesis of compound aa2-006, Fmoc-MeGly(cPent)-MeAsp-NMe2

[0229] Synthesis of compound aa2-006-a, (3S)-4-(dimethylamino)-3-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-4-oxobutanoate prop-2-enyl (Fmoc-MeAsp(OAl)-NMe2) The starting material, Fmoc-MeAsp(OAl)-OH, was synthesized according to the method described in WO2018 / 225864. Under a nitrogen stream, EDCI (16.9 g, 88.0 mmol) and DMF (144 mL) were added to a reaction vessel and cooled to 0 °C. HOBt (10.9 g, 80.6 mmol) and a solution of Fmoc-MeAsp(OAl)-OH (30.0 g, 73.3 mmol) in DCM / DMF (60 mL / 60 mL) were added sequentially at 0 °C and stirred at 0 °C for 30 min. Dimethylamine (2 mol / L THF solution, 40.5 mL, 80.6 mmol) was added dropwise at 0 °C, followed by stirring at 0 °C for 30 min. Ethyl acetate (300 mL) was added to the reaction mixture, and the organic layer was washed twice with 1 mol / L aqueous hydrochloric acid (240 mL), twice with water (300 mL), twice with saturated aqueous sodium bicarbonate / water (1 / 1, 300 mL), and once with saturated aqueous sodium chloride / water (1 / 1, 300 mL). The organic layer was then dried over sodium sulfate. After filtering off the drying agent, the filtrate was concentrated under reduced pressure to give compound aa2-006-a (32.7 g, 102% yield) as pale brown amorphous crystals. LCMS (ESI) m / z = 437.2 (M+H) + Retention time: 0.86 minutes (Analysis conditions SQDFA05)

[0230] Synthesis of compound aa2-006-b, (3S)-3-[[(2S)-2-cyclopentyl-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]acetyl]-methylamino]-4-(dimethylamino)-4-oxobutanoate prop-2-enyl (Fmoc-MeGly(cPent)-MeAsp(OAl)-NMe2) Compound aa2-006-a (8.50 g, 19.5 mmol) and Fmoc-MeGly(cPent)-OH (7.76 g, 20.5 mmol) were used as starting materials, and compound aa2-006-b was obtained as yellow amorphous crystals (5.02 g, 43% yield) in the same manner as in the synthesis of compound aa2-001-a. LCMS (ESI) m / z = 576.5 (M+H). + Retention time: 1.02 minutes (Analysis conditions SQDFA05)

[0231] Synthesis of compound aa2-006, (3S)-3-[[(2S)-2-cyclopentyl-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]acetyl]-methylamino]-4-(dimethylamino)-4-oxobutanoic acid (Fmoc-MeGly(cPent)-MeAsp-NMe2) Using compound aa2-006-b (0.921 g, 1.60 mmol) as the starting material, compound aa2-006 was obtained as pale brown amorphous crystals (0.786 g, 92% yield) in the same manner as compound aa2-001. LCMS (ESI) m / z = 536.5 (M+H) + Retention time: 0.85 minutes (Analysis conditions SQDFA05)

[0232] Synthesis of compound aa2-007, Fmoc-MeLeu-MeAsp-NMe2

[0233] Synthesis of compound aa2-007-b, (3S)-4-(dimethylamino)-3-[[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-4-methylpentanoyl]-methylamino]-4-oxobutanoate prop-2-enyl (Fmoc-MeLeu-MeAsp(OAl)-NMe2) Compound aa2-006-a (8.50 g, 19.5 mmol) and Fmoc-MeLeu-OH (7.76 g, 20.5 mmol) were used as starting materials, and compound aa2-007-b was obtained as yellow amorphous crystals (5.00 g, 48% yield) in the same manner as in the synthesis of compound aa2-001-a. LCMS (ESI) m / z = 564.5 (M+H). + Retention time: 1.02 minutes (Analysis conditions SQDFA05)

[0234] Synthesis of compound aa2-007, (3S)-4-(dimethylamino)-3-[[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-4-methylpentanoyl]-methylamino]-4-oxobutanoic acid (Fmoc-MeLeu-MeAsp-NMe2) Using compound aa2-007-b (1.13 g, 2.00 mmol) as the starting material, compound aa2-007 was obtained as pale brown amorphous crystals (0.995 g, 95% yield) in the same manner as compound aa2-001. LCMS (ESI) m / z = 524.5 (M+H) + Retention time: 0.86 minutes (Analysis conditions SQDFA05)

[0235] Synthesis of compound aa2-008, Fmoc-MeVal-D-3-MeAbu-OH

[0236] Synthesis of compound aa2-008-a, (3R)-3-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]butanoate prop-2-enyl (Fmoc-D-3-MeAbu-OAl) Fmoc-D-3-MeAbu-OH (20.0 g, 59.0 mmol), EDCI (17.0 g, 88.5 mmol), HOBt (13.6 g, 88.5 mmol), allyl alcohol (8.1 mL, 118 mmol), DMF (140 mL), and DCM (40 mL) were added to a reaction vessel under a nitrogen stream at 0 °C and stirred for 30 min. DIPEA (15.4 mL, 88.5 mmol) was then added, and the mixture was stirred for 30 min at 0 °C and then at room temperature for 15 min. Ethyl acetate (200 mL) was added to the reaction mixture, and the organic layer was washed with saturated aqueous sodium bicarbonate (200 mL) and dried over sodium sulfate. The drying agent was removed by filtration, and the filtrate was concentrated under reduced pressure to obtain 22.1 g (99% yield) of crude compound aa2-008-a as a yellow oil. LCMS(ESI) m / z = 380.1 (M+H) + Retention time: 2.12 minutes (Analysis conditions SMDmethod_1)

[0237] Synthesis of compound aa2-008-b, (3R)-3-[[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-3-methylbutanoyl]-methylamino]butanoate prop-2-enyl (Fmoc-MeVal-D-3-MeAbu-OAl) Using compound aa2-008-a (6.00 g, 15.8 mmol) and Fmoc-MeVal-OH (5.82 g, 16.62 mmol) as starting materials, compound aa2-008-b was obtained as brown amorphous crystals (3.79 g, 49% yield) in the same manner as in the synthesis of compound aa2-001-a. LCMS (ESI) m / z = 493.5 (M+H) + Retention time: 1.03 minutes (Analysis conditions SQDFA05)

[0238] Synthesis of compound aa2-008, (3R)-3-[[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-3-methylbutanoyl]-methylamino]butanoic acid (Fmoc-MeVal-D-3-MeAbu-OH) Using compound aa2-008-b (0.788 g, 1.60 mmol) as the starting material, compound aa2-008 was obtained as pale brown amorphous crystals (0.607 g, 84% yield) in the same manner as compound aa2-001. LCMS (ESI) m / z = 453.4 (M+H) + Retention time: 0.85 minutes (Analysis conditions SQDFA05)

[0239] Synthesis of compound aa2-009, Fmoc-MeChg-D-3-MeAbu-OH

[0240] Synthesis of compound aa2-009-b, (3R)-3-[[(2S)-2-cyclohexyl-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]acetyl]-methylamino]butanoate prop-2-enyl (Fmoc-MeChg-D-3-MeAbu-OAl) Using compound aa2-008-a (4.70 g, 12.4 mmol) and Fmoc-MeChg-OH (5.10 g, 13.0 mmol) as starting materials, compound aa2-009-b was obtained as a yellow oily substance (3.70 g, 56% yield) in the same manner as in the synthesis of compound aa2-001-a. LCMS (ESI) m / z = 533.6 (M+H) + Retention time: 1.11 minutes (Analysis conditions SQDFA05)

[0241] Synthesis of compound aa2-009, (3R)-3-[[(2S)-2-cyclohexyl-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]acetyl]-methylamino]butanoic acid (Fmoc-MeChg-D-3-MeAbu-OH) Using compound aa2-009-b (0.799 g, 1.50 mmol) as the starting material, compound aa2-009 was obtained as pale brown amorphous crystals (0.501 g, 68% yield) in the same manner as compound aa2-001. LCMS (ESI) m / z = 493.5 (M+H) + Retention time: 0.95 minutes (Analysis conditions SQDFA05)

[0242] Synthesis of compound aa2-010, Fmoc-MeVal-MeGly-OH

[0243] Synthesis of compound aa2-010-a, 2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]prop-2-enyl acetate (Fmoc-MeGly-OAl) Fmoc-MeGly-OH (6.00 g, 19.3 mmol), EDCI (4.43 g, 23.1 mmol), HOBt (3.12 g, 23.1 mmol), allyl alcohol (1.23 g, 21.2 mmol), DMF (40 mL), and DCM (12 mL) were added to a reaction vessel under a nitrogen stream and stirred at room temperature for 30 minutes. Ethyl acetate (60 mL) was added to the reaction mixture, and the organic layer was washed with 1 mol / L aqueous hydrochloric acid (60 mL), saturated aqueous sodium bicarbonate (60 mL), and saturated aqueous sodium chloride (60 mL), respectively. The organic layer was then concentrated under reduced pressure to afford compound aa2-010-a (6.00 g, 89% yield) as a yellow oil. LCMS (ESI) m / z = 352.1 (M+H). + Retention time: 1.75 minutes (Analysis conditions SMDmethod_2)

[0244] Synthesis of compound aa2-010-b, 2-[[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-3-methylbutanoyl]-methylamino]prop-2-enyl acetate (Fmoc-MeVal-MeGly-OAl) Compound aa2-010-a (6.00 g, 17.07 mmol) and Fmoc-MeVal-OH (6.63 g, 18.76 mmol) were used as starting materials, and compound aa2-010-b was obtained as pink amorphous crystals (3.37 g, 43% yield) in the same manner as in the synthesis of compound aa2-001-a. LCMS (ESI) m / z = 465.5 (M+H). + Retention time: 1.00 minutes (Analysis conditions SQDFA05)

[0245] Synthesis of compound aa2-010, 2-[[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-3-methylbutanoyl]-methylamino]acetic acid (Fmoc-MeVal-MeGly-OH) Using compound aa2-010-b (0.929 g, 2.00 mmol) as the starting material, compound aa2-010 was obtained as pale brown amorphous crystals (0.841 g, 99% yield) in the same manner as compound aa2-001. LCMS (ESI) m / z = 425.4 (M+H) + Retention time: 0.83 minutes (Analysis conditions SQDFA05)

[0246] Synthesis of compound aa2-011, Fmoc-MeGly(cPent)-MeAsp-mor

[0247] Synthesis of compound aa2-011-a, (3S)-3-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-4-morpholino-4-oxo-butanoic acid allyl ester (Fmoc-MeAsp(OAl)-mor) The starting material, Fmoc-MeAsp(OAl)-OH, was synthesized according to the method described in WO2018 / 225864. The condensation reaction of the carboxyl group with morpholine was carried out by using morpholine instead of dimethylamine, which was used in the synthesis of compound aa2-006-a.

[0248] Synthesis of compound aa2-011-b, (3S)-3-[[(2S)-2-cyclopentyl-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]acetyl]-methyl-amino]-4-morpholino-4-oxo-butanoate allyl ester (Fmoc-MeGly(cPent)-MeAsp(OAl)-mor) Under a nitrogen atmosphere, DBU (3.15 mL, 20.90 mmol) was added dropwise to a solution of compound aa2-011-a (10 g, 20.90 mmol) in anhydrous DMF (50 mL) at room temperature and stirred for 10 minutes. Pyridine hydrochloride (2.66 g, 22.99 mmol) was added to the reaction mixture at room temperature and stirred for 10 minutes. A separately prepared activated ester solution (described below) was added to the reaction mixture at room temperature, followed by the dropwise addition of DIPEA (4.01 mL, 22.99 mmol). The resulting reaction mixture was stirred at room temperature for 4 hours and 15 minutes, after which ethyl acetate (100 mL), hexane (20 mL), and 1 mol / L aqueous hydrochloric acid (100 mL) were added. The resulting mixture was extracted with ethyl acetate-hexane (5:1) (total organic phase volume: approximately 300 mL). The organic phase was washed with 1 mol / L aqueous hydrochloric acid (100 mL), water (100 mL), aqueous sodium bicarbonate (100 mL x 2), and saturated aqueous sodium chloride (100 mL). After drying over sodium sulfate, the solvent was evaporated under reduced pressure. The resulting crude product was purified by normal-phase silica gel chromatography (hexane-ethyl acetate) to yield compound aa2-011-b (9.98 g, 81% yield). The activated ester solution was prepared as follows. Under a nitrogen atmosphere, anhydrous DMF (55 mL) was added to a mixture of (2S)-2-cyclopentyl-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]acetic acid (7.53 g, 19.85 mmol), WSCI·HCl (5.21 g, 27.2 mmol), and Oxyma (3.56 g, 25.08 mmol) at room temperature. The resulting reaction mixture was stirred for 40 minutes and used as an activated ester solution. LCMS(ESI) m / z = 618 (M+H). + Retention time: 0.96 minutes (Analysis conditions SQDFA05)

[0249] Synthesis of compound aa2-011, (3S)-3-[[(2S)-2-cyclopentyl-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]acetyl]-methyl-amino]-4-morpholino-4-oxo-butanoic acid (Fmoc-MeGly(cPent)-MeAsp-mor) Under a nitrogen atmosphere, anhydrous DCM (15 mL) was added to a mixture of compound aa2-011-b (9.90 g, 16.03 mmol) and tetrakis(triphenylphosphine)palladium(0) (0.185 g, 0.16 mmol) and stirred at room temperature. Phenylsilane (1.38 mL, 11.22 mmol) was added dropwise to the resulting solution. After stirring for 30 min, MTBE (100 mL) was added, followed by the slow dropwise addition of aqueous sodium bicarbonate (2-fold diluted from saturated aqueous solution) (100 mL) to quench the reaction. The resulting mixture was extracted twice with water (total aqueous phase volume approximately 150 mL), and DCM (100 mL) and phosphoric acid (5.6 mL) were added to the aqueous phase. The resulting mixture was extracted twice with DCM (total organic phase volume: approximately 200 mL). The organic phase was washed with saturated aqueous sodium chloride (80 mL x 2) and dried over sodium sulfate. The solvent was then distilled off under reduced pressure to give compound aa2-011 (9.57 g, yield: 100%), which was used in the next reaction. LCMS (ESI) m / z = 578 (M+H) + Retention time: 0.79 minutes (Analysis conditions SQDFA05)

[0250] Synthesis of compound aa2-012, Fmoc-MeVal-Asp-NMe2

[0251] Synthesis of compound aa2-012-a, (3S)-4-(dimethylamino)-3-(9H-fluoren-9-ylmethoxycarbonylamino)-4-oxobutanoate prop-2-enyl (Fmoc-Asp(OAl)-NMe2) Starting from Fmoc-Asp(OAl)-OH (100.0 g, 252.9 mmol) purchased from a commercial supplier, compound aa2-012-a was synthesized in a similar manner to compound aa2-006-a to afford compound aa2-012-a as a yellow oil (89 g, 82% yield). LCMS (ESI) m / z = 423.2 (M+H). + Retention time: 2.24 minutes (Analysis conditions SMDmethod_3)

[0252] Synthesis of compound aa2-012-b, (3S)-4-(dimethylamino)-3-[[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-3-methylbutanoyl]amino]-4-oxobutanoate prop-2-enyl (Fmoc-MeVal-Asp(OAl)-NMe2) Using compound aa2-012-a (5.0 g, 11.8 mmol) and Fmoc-MeVal-OH (4.39 g, 12.4 mmol) as starting materials, compound aa2-012-b was obtained as a gray-white solid (3.4 g, 53% yield) in a manner similar to that used for the synthesis of compound aa2-001-a. LCMS (ESI) m / z = 536.5 (M+H) + Retention time: 0.94 minutes (Analysis conditions SQDFA05)

[0253] Synthesis of compound aa2-012, (3S)-4-(dimethylamino)-3-[[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-3-methylbutanoyl]amino]-4-oxobutanoic acid (Fmoc-MeVal-Asp-NMe2) Using compound aa2-012-b (1.16 g, 2.17 mmol) as the starting material, compound aa2-012 was obtained as white amorphous crystals (1.02 g, 95% yield) in the same manner as compound aa2-001. LCMS (ESI) m / z = 496.5 (M+H) + Retention time: 0.78 minutes (Analysis conditions SQDFA05)

[0254] Synthesis of compound aa2-013, Fmoc-Gly-MeAsp-NMe2

[0255] Synthesis of compound aa2-013-b, (3S)-4-(dimethylamino)-3-[[2-(9H-fluoren-9-ylmethoxycarbonylamino)acetyl]-methylamino]-4-oxobutanoate prop-2-enyl (Fmoc-Gly-MeAsp(OAl)-NMe2) Using compound aa2-006-a (5.0 g, 11.5 mmol) and Fmoc-Gly-OH (7.15 g, 24.1 mmol) as starting materials, compound aa2-013-b was obtained as yellow amorphous crystals (3.9 g, 68% yield) in the same manner as in the synthesis of compound aa2-001-a. LCMS (ESI) m / z = 494.5 (M+H) + Retention time: 0.81 min (Analysis conditions SQDFA05)

[0256] Synthesis of compound aa2-013, (3S)-4-(dimethylamino)-3-[[2-(9H-fluoren-9-ylmethoxycarbonylamino)acetyl]-methylamino]-4-oxobutanoic acid (Fmoc-Gly-MeAsp-NMe2) Using compound aa2-013-b (1.07 g, 2.17 mmol) as the starting material, compound aa2-013 was obtained as pale brown amorphous crystals (1.01 g, 103% yield) in the same manner as compound aa2-001. LCMS (ESI) m / z = 454.4 (M+H) + Retention time: 0.67 minutes (Analysis conditions SQDFA05)

[0257] Synthesis of compound aa2-014, Fmoc-Aib-MeAsp-NMe2

[0258] Synthesis of compound aa2-014-a, (3S)-4-(dimethylamino)-3-(methylamino)-4-oxobutanoate prop-2-enyl (H-MeAsp(OAl)-NMe2) Compound aa2-006-a (18.0 g, 41.2 mmol) and DCM (180 mL) were added to a reaction vessel, followed by DBU (6.28 g, 41.2 mmol) at room temperature. The reaction mixture was stirred for 5 minutes, then concentrated under reduced pressure. The resulting residue was purified by normal-phase silica gel column chromatography (petroleum ether / ethyl acetate = 100 / 0 → 0 / 100, then DCM / methanol = 100 / 0 → 85 / 15) to afford compound aa2-014-a as a yellow oil (8.1 g, 87% yield). LCMS(ESI) m / z = 215.2 (M+H) + Retention time: 0.41 minutes (Analysis conditions SMDmethod_4)

[0259] Synthesis of compound aa2-014-b, (3S)-4-(dimethylamino)-3-[[2-(9H-fluoren-9-ylmethoxycarbonylamino)-2-methylpropanoyl]-methylamino]-4-oxobutanoate prop-2-enyl (Fmoc-Aib-MeAsp(OAl)-NMe2) Compound aa2-014-a (4.35 g, 20.3 mmol), Fmoc-Aib-OH (6.0 g, 18.4 mmol), COMU (11.8 g, 27.7 mmol), and DMF (60 mL) were added to a reaction vessel under a nitrogen stream, followed by dropwise addition of DIPEA (2.38 g, 18.4 mmol) at 0 °C. The reaction mixture was stirred at 40 °C for 16 hours, after which ethyl acetate (120 mL) was added to the reaction mixture. The organic layer was washed twice with 1 mol / L aqueous hydrochloric acid (60 mL), once with water (60 mL), twice with saturated aqueous sodium bicarbonate (60 mL), and then with saturated aqueous sodium chloride (60 mL). The organic layer was then dried over sodium sulfate. After filtering off the drying agent, the filtrate was concentrated under reduced pressure. The resulting residue was purified by normal-phase silica gel column chromatography (petroleum ether / ethyl acetate = 100 / 0 → 50 / 50) and then reverse-phase silica gel column chromatography (water / acetonitrile = 95 / 5 → 50 / 50) to obtain compound aa2-014-b as a yellow solid (3.31 g, 37% yield). LCMS(ESI) m / z = 522.5 (M+H) +Retention time: 0.85 minutes (Analysis conditions SQDFA05)

[0260] Synthesis of compound aa2-014, (3S)-4-(dimethylamino)-3-[[2-(9H-fluoren-9-ylmethoxycarbonylamino)-2-methylpropanoyl]-methylamino]-4-oxobutanoic acid (Fmoc-Aib-MeAsp-NMe2) Using compound aa2-014-b (1.14 g, 2.19 mmol) as the starting material, compound aa2-014 was obtained as pale brown amorphous crystals (1.04 g, 99% yield) in the same manner as compound aa2-001. LCMS (ESI) m / z = 482.4 (M+H) + Retention time: 0.70 minutes (Analysis conditions SQDFA05)

[0261] Synthesis of compound aa2-015, Fmoc-bAla(2-Me2)-D-3-MeAbu-OH

[0262] Synthesis of compound aa2-015-b, (3R)-3-[[3-(9H-fluoren-9-ylmethoxycarbonylamino)-2,2-dimethylpropanoyl]-methylamino]butanoate prop-2-enyl (Fmoc-bAla(2-Me2)-D-3-MeAbu-OAl) Using compound aa2-008-a (8.0 g, 21.1 mmol) and Fmoc-bAla(2-Me2)-OH (7.5 g, 22.2 mmol) as starting materials, compound aa2-015-b was obtained as a pale yellow oily substance (1.28 g, 13% yield) in the same manner as in the synthesis of compound aa2-001-a. LCMS (ESI) m / z = 479.5 (M+H) + Retention time: 1.00 minutes (Analysis conditions SQDFA05)

[0263] Synthesis of compound aa2-015, (3R)-3-[[3-(9H-fluoren-9-ylmethoxycarbonylamino)-2,2-dimethylpropanoyl]-methylamino]butanoic acid (Fmoc-bAla(2-Me2)-D-3-MeAbu-OH) Compound aa2-015-b (602 mg, 1.26 mmol) and tetrakis(triphenylphosphine)palladium (14.5 mg, 0.013 mmol) were added to a reaction vessel under a nitrogen atmosphere, followed by DCM (2.5 mL). Phenylsilane (95 mg, 0.88 mmol) was added dropwise to the reaction mixture, and the mixture was stirred at room temperature for 30 min. Tetrakis(triphenylphosphine)palladium (14.5 mg, 0.013 mmol) and phenylsilane (95 mg, 0.88 mmol) were then added to the reaction mixture, and the mixture was stirred at room temperature for 30 min. The reaction mixture was diluted with TBME (6.0 mL) and extracted with saturated aqueous sodium bicarbonate / water (1 / 1, 6.0 mL) followed by water (3.0 mL). The combined aqueous layers were acidified to approximately pH 2 with 85% aqueous phosphoric acid (0.516 mL, 7.55 mmol), and the aqueous layer was extracted twice with DCM (6.0 mL). The combined organic layers were washed with saturated aqueous sodium chloride / water (1 / 1, 6.0 mL) and then dried over sodium sulfate. After filtering off the drying agent, the filtrate was concentrated under reduced pressure. The resulting residue was purified by reverse-phase silica gel column chromatography (water / acetonitrile = 90 / 10 → 30 / 70) to obtain compound aa2-015 as a white solid (285 mg, 52% yield). LCMS (ESI) m / z = 439.5 (M+H) + Retention time: 0.80 minutes (Analysis conditions SQDFA05)

[0264] Synthesis of compound aa2-016, Fmoc-MeLeu-MeVal-OH

[0265] Synthesis of compound aa2-016-a, (2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-3-methylbutanoate prop-2-enyl (Fmoc-MeVal-OAl) Fmoc-MeVal-OH (2.00 g, 5.66 mmol), allyl bromide (0.75 g, 6.20 mmol), potassium carbonate (1.17 g, 8.47 mmol), and DMF (20 mL) were added to a reaction vessel under a nitrogen stream, and the reaction mixture was stirred at room temperature for 4 hours. After filtration, the filtrate was neutralized with 1 mol / L aqueous hydrochloric acid at 0 °C and extracted three times with ethyl acetate. The combined organic layers were washed once with water and twice with saturated aqueous sodium chloride, and then dried over sodium sulfate. After filtering off the drying agent, the filtrate was concentrated under reduced pressure. The residue was purified by normal-phase silica gel column chromatography (petroleum ether / ethyl acetate = 100 / 0 → 90 / 10) to give compound aa2-016-a as a colorless oil (1.9 g, 85% yield). LCMS (ESI) m / z = 394.2 (M+H). + Retention time: 1.21 minutes (Analysis conditions SMDmethod_5)

[0266] Synthesis of compound aa2-016-b, (2S)-2-[[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-4-methylpentanoyl]-methylamino]-3-methylbutanoate prop-2-enyl (Fmoc-MeLeu-MeVal-OAl) Using compound aa2-016-a (1.0 g, 2.64 mmol) and Fmoc-MeLeu-OH (1.02 g, 2.77 mmol) as starting materials, compound aa2-016-b was obtained as a colorless oil (0.90 g, 64% yield) in the same manner as in the synthesis of compound aa2-001-a. LCMS (ESI) m / z = 521.6 (M+H) + Retention time: 1.16 minutes (Analysis conditions SQDFA05)

[0267] Synthesis of compound aa2-016, (2S)-2-[[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-4-methylpentanoyl]-methylamino]-3-methylbutanoic acid (Fmoc-MeLeu-MeVal-OH) Using compound aa2-016-b (417 mg, 0.80 mmol) as the starting material, 185 mg (48% yield) of compound aa2-016 was obtained as pale brown amorphous crystals in the same manner as in the synthesis of compound aa2-001. LCMS (ESI) m / z = 481.5 (M+H) + Retention time: 0.97 minutes (Analysis conditions SQDFA05)

[0268] Synthesis of compound aa2-017, Fmoc-MeVal-Pro-OH

[0269] Synthesis of compound aa2-017-a, (2S)-pyrrolidine-1,2-dicarboxylic acid 2-O-prop-2-enyl 1-O-(9H-fluoren-9-ylmethyl) (Fmoc-Pro-OAl) Using Fmoc-Pro-OH (5.00 g, 14.8 mmol) as the starting material, compound aa2-017-a was obtained as a colorless oily substance (5.3 g, 94% yield) in the same manner as in the synthesis of compound aa2-016-a. LCMS (ESI) m / z = 378.2 (M+H) + Retention time: 1.10 minutes (Analysis conditions SMDmethod_5)

[0270] Synthesis of compound aa2-017-b, (2S)-1-[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-3-methylbutanoyl]pyrrolidine-2-carboxylate prop-2-enyl (Fmoc-MeVal-Pro-OAl) Using compound aa2-017-a (5.3 g, 14.0 mmol) and Fmoc-MeVal-OH (5.21 g, 14.7 mmol) as starting materials, compound aa2-017-b was obtained as a colorless oily substance (5.2 g, 74% yield) in the same manner as in the synthesis of compound aa2-001-a. LCMS (ESI) m / z = 491.5 (M+H) + Retention time: 1.00 minutes (Analysis conditions SQDFA05)

[0271] Synthesis of compound aa2-017, (2S)-1-[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-3-methylbutanoyl]pyrrolidine-2-carboxylic acid (Fmoc-MeVal-Pro-OH) Using compound aa2-017-b (1.57 g, 3.20 mmol) as the starting material, compound aa2-017 was obtained as pale brown amorphous crystals (1.35 g, 94% yield) in the same manner as in the synthesis of compound aa2-001. LCMS (ESI) m / z = 451.5 (M+H) + Retention time: 0.81 min (Analysis conditions SQDFA05)

[0272] Synthesis of compound aa2-018, Fmoc-MeLeu-Aib-OH

[0273] Synthesis of compound aa2-018-a, 2-(9H-fluoren-9-ylmethoxycarbonylamino)-2-methylpropanoate prop-2-enyl (Fmoc-Aib-OAl) Using Fmoc-Aib-OH (7.00 g, 21.5 mmol) as the starting material, compound aa2-018-a was obtained as a colorless oil (7.5 g, 94% yield) in the same manner as in the synthesis of compound aa2-016-a. LCMS (ESI) m / z = 366.1 (M+H) + Retention time: 1.08 minutes (Analysis conditions SMDmethod_5)

[0274] Synthesis of compound aa2-018-b, 2-[[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-4-methylpentanoyl]amino]-2-methylpropanoate prop-2-enyl (Fmoc-MeLeu-Aib-OAl) Using compound aa2-018-a (7.00 g, 19.2 mmol) and Fmoc-MeLeu-OH (7.39 g, 20.1 mmol) as starting materials, compound aa2-018-b was obtained as a yellow oily substance (6.2 g, 65% yield) in the same manner as in the synthesis of compound aa2-001-a. LCMS (ESI) m / z = 493.5 (M+H) +Retention time: 1.07 minutes (Analysis conditions SQDFA05)

[0275] Synthesis of compound aa2-018, 2-[[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-4-methylpentanoyl]amino]-2-methylpropanoic acid (Fmoc-MeLeu-Aib-OH) Using compound aa2-018-b (985 mg, 2.00 mmol) as the starting material, 608 mg (67% yield) of compound aa2-018 was obtained as pale brown amorphous crystals in the same manner as in the synthesis of compound aa2-001. LCMS (ESI) m / z = 453.5 (M+H) + Retention time: 0.91 minutes (Analysis conditions SQDFA05)

[0276] Synthesis of compound aa2-019, Fmoc-MeVal-Gly-OH

[0277] Synthesis of compound aa2-019-a, 2-(9H-fluoren-9-ylmethoxycarbonylamino)prop-2-enyl acetate (Fmoc-Gly-OAl) Using Fmoc-Gly-OH (7.00 g, 23.5 mmol) as the starting material, compound aa2-019-a was obtained as a colorless oil (7.5 g, 91% yield) in the same manner as in the synthesis of compound aa2-016-a. LCMS (ESI) m / z = 338.2 (M+H) + Retention time: 1.16 minutes (Analysis conditions SMDmethod_6)

[0278] Synthesis of compound aa2-019-b, 2-[[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-3-methylbutanoyl]amino]prop-2-enyl acetate (Fmoc-MeVal-Gly-OAl) Using compound aa2-019-a (5.0 g, 14.8 mmol) and Fmoc-MeVal-OH (5.5 g, 15.6 mmol) as starting materials, compound aa2-019-b was obtained as a colorless oil (4.3 g, 64% yield) in the same manner as in the synthesis of compound aa2-001-a. LCMS (ESI) m / z = 451.5 (M+H)+ Retention time: 0.96 minutes (Analysis conditions SQDFA05)

[0279] Synthesis of compound aa2-019, 2-[[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-3-methylbutanoyl]amino]acetic acid (Fmoc-MeVal-Gly-OH) Using compound aa2-019-b (1.47 g, 3.27 mmol) as the starting material, compound aa2-019 was obtained as pale brown amorphous crystals (1.31 g, 98% yield) in the same manner as compound aa2-001. LCMS (ESI) m / z = 411.4 (M+H) + Retention time: 0.79 minutes (Analysis conditions SQDFA05)

[0280] Synthesis of compound aa2-020, Fmoc-D-MeVal-MeAsp-NMe2

[0281] Synthesis of compound aa2-020-b, (3S)-4-(dimethylamino)-3-[[(2R)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-3-methylbutanoyl]-methylamino]-4-oxobutanoate prop-2-enyl (Fmoc-D-MeVal-MeAsp(OAl)-NMe2) Using compound aa2-006-a (5.00 g, 11.5 mmol) and Fmoc-D-MeVal-OH (4.08 g, 11.5 mmol) as starting materials, compound aa2-020-b was obtained as a white solid (3.1 g, 49% yield) in the same manner as in the synthesis of compound aa2-001-a. LCMS (ESI) m / z = 550.5 (M+H) + Retention time: 0.98 minutes (Analysis conditions SQDFA05)

[0282] Synthesis of compound aa2-020, (3S)-4-(dimethylamino)-3-[[(2R)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-3-methylbutanoyl]-methylamino]-4-oxobutanoic acid (Fmoc-D-MeVal-MeAsp-NMe2) Using compound aa2-020-b (1.37 g, 2.50 mmol) as the starting material, compound aa2-020 was obtained as white amorphous crystals (1.20 g, 94% yield) in the same manner as in the synthesis of compound aa2-001. LCMS (ESI) m / z = 510.5 (M+H) + Retention time: 0.79 minutes (Analysis conditions SQDFA05)

[0283] Synthesis of compound aa2-021, Fmoc-bAla(2-Me2)-MeAsp-NMe2

[0284] Synthesis of compound aa2-021-b, (3S)-4-(dimethylamino)-3-[[3-(9H-fluoren-9-ylmethoxycarbonylamino)-2,2-dimethylpropanoyl]-methylamino]-4-oxobutanoate prop-2-enyl (Fmoc-bAla(2-Me2)-MeAsp(OAl)-NMe2) Using compound aa2-014-a (5.92 g, 27.6 mmol) and Fmoc-bAla(2-Me2)-OH (8.6 g, 25.3 mmol) as starting materials, compound aa2-021-b was obtained as a yellow solid (3.63 g, 26% yield) in a manner similar to that used for the synthesis of compound aa2-014-b. LCMS (ESI) m / z = 536.6 (M+H) + Retention time: 0.90 minutes (Analysis conditions SQDFA05)

[0285] Synthesis of compound aa2-021, (3S)-4-(dimethylamino)-3-[[3-(9H-fluoren-9-ylmethoxycarbonylamino)-2,2-dimethylpropanoyl]-methylamino]-4-oxobutanoic acid (Fmoc-bAla(2-Me2)-MeAsp-NMe2) Using compound aa2-021-b (1.07 g, 2.00 mmol) as the starting material, compound aa2-021 was obtained as pale brown amorphous crystals (874 mg, 88% yield) in the same manner as in the synthesis of compound aa2-001. LCMS (ESI) m / z = 496.5 (M+H) + Retention time: 0.74 minutes (Analysis conditions SQDFA05)

[0286] Synthesis of compound aa2-022, Fmoc-MeVal-D-MeAsp-NMe2

[0287] Synthesis of compound aa2-022-a, (4R)-5-oxo-4-(2-oxo-2-prop-2-enoxyethyl)-1,3-oxazolidine-3-carboxylate 9H-fluoren-9-ylmethyl Under a nitrogen stream, Fmoc-D-Asp(OAl)-OH (20.0 g, 50.6 mmol), paraformaldehyde (4.56 g, 152 mmol), p-toluenesulfonic acid (0.09 g, 0.506 mmol), and toluene (500 mL) were added to a reaction vessel, and the reaction mixture was stirred at 90 °C for 16 hours. After cooling the reaction mixture to room temperature, the solvent was evaporated under reduced pressure. The resulting residue was dissolved in TBME and washed with aqueous sodium carbonate. The organic phase was then dried over sodium sulfate. After removing the drying agent by filtration, the filtrate was concentrated under reduced pressure to obtain compound aa2-022-a as a yellow oil (20 g, 90% yield). LCMS (ESI) m / z = 408.2 (M+H) + Retention time: 1.05 minutes (Analysis conditions SMDmethod_5)

[0288] Synthesis of compound aa2-022-b, (2R)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-4-oxo-4-prop-2-enoxybutanoic acid (Fmoc-D-MeAsp(OAl)-OH) Compound aa2-022-a (20 g, 49.1 mmol), triethylsilane (11.4 g, 98.2 mmol), DCM (200 mL), and zinc bromide (11.1 g, 49.1 mmol) were added to a reaction vessel under a nitrogen stream. The reaction mixture was stirred at room temperature for 48 hours, after which the solvent was removed under reduced pressure. The resulting residue was dissolved in aqueous potassium carbonate and washed twice with hexane. The aqueous phase was adjusted to pH 2 with hydrochloric acid, extracted three times with ethyl acetate, and the organic phase was dried over sodium sulfate. After removing the drying agent by filtration, the filtrate was concentrated under reduced pressure to obtain compound aa2-022-b (15 g, 93% yield) as a white solid. LCMS (ESI) m / z = 410.2 (M+H) +Retention time: 0.98 minutes (Analysis conditions SMDmethod_5)

[0289] Synthesis of compound aa2-022-c, (3R)-4-(dimethylamino)-3-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-4-oxobutanoate prop-2-enyl (Fmoc-D-MeAsp(OAl)-NMe2) Using compound aa2-022-b (15.7 g, 38.3 mmol) as the starting material, compound aa2-022-c was obtained as a yellow oily substance (13 g, 78% yield) in the same manner as in the synthesis of compound aa2-006-a. LCMS (ESI) m / z = 437.2 (M+H) + Retention time: 1.86 minutes (Analysis conditions SMDmethod_7)

[0290] Synthesis of compound aa2-022-d, (3R)-4-(dimethylamino)-3-[[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-3-methylbutanoyl]-methylamino]-4-oxobutanoate prop-2-enyl (Fmoc-MeVal-D-MeAsp(OAl)-NMe2) Using compound aa2-022-c (7.00 g, 16.0 mmol) and Fmoc-MeVal-OH (6.23 g, 17.6 mmol) as starting materials, compound aa2-022-d was obtained as a white solid (3.34 g, 35% yield) in the same manner as in the synthesis of compound aa2-001-a. LCMS (ESI) m / z = 550.6 (M+H) + Retention time: 0.97 minutes (Analysis conditions SQDFA05)

[0291] Synthesis of compound aa2-022, (3R)-4-(dimethylamino)-3-[[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-3-methylbutanoyl]-methylamino]-4-oxobutanoic acid (Fmoc-MeVal-D-MeAsp-NMe2) Using compound aa2-022-d (1.37 g, 2.50 mmol) as the starting material, compound aa2-022 was obtained as white amorphous crystals (1.26 g, 99% yield) in the same manner as in the synthesis of compound aa2-001. LCMS (ESI) m / z = 510.5 (M+H) + Retention time: 0.79 minutes (Analysis conditions SQDFA05)

[0292] Synthesis of compound aa2-023, Fmoc-Ala-MeGly(cPent)-MeAsp-NMe2

[0293] Synthesis of compound aa2-023-b, (3S)-3-[[(2S)-2-cyclopentyl-2-[[(2S)-2-(9H-fluoren-9-ylmethoxycarbonylamino)propanoyl]-methylamino]acetyl]-methylamino]-4-(dimethylamino)-4-oxobutanoate prop-2-enyl (Fmoc-Ala-MeGly(cPent)-MeAsp(OAl)-NMe2). Compound aa2-006-b (1.17 g, 2.03 mmol) and Fmoc-Ala-OH (601 mg, 1.93 mmol) were used as starting materials, and compound aa2-023-b was obtained as yellow amorphous crystals (575 mg, 44% yield) in the same manner as in the synthesis of compound aa2-001-a. LCMS (ESI) m / z = 647.7 (M+H). + Retention time: 0.98 minutes (Analysis conditions SQDFA05)

[0294] Synthesis of compound aa2-023, (3S)-3-[[(2S)-2-cyclopentyl-2-[[(2S)-2-(9H-fluoren-9-ylmethoxycarbonylamino)propanoyl]-methylamino]acetyl]-methylamino]-4-(dimethylamino)-4-oxobutanoic acid (Fmoc-Ala-MeGly(cPent)-MeAsp-NMe2) Compound aa2-023-b (575 mg, 0.889 mmol) was used as the starting material, and the crude product aa2-023 was obtained using the same method as for the synthesis of compound aa2-001. The crude product was dissolved in DMSO and purified by reverse-phase silica gel column chromatography (water / acetonitrile = 85 / 15 → 20 / 80) to obtain compound aa2-023 as a white solid (476 mg, 88% yield). LCMS (ESI) m / z = 607.6 (M+H) + Retention time: 0.83 minutes (Analysis conditions SQDFA05)

[0295] Example 1-3. Synthesis of Fmoc-amino acids The Fmoc-amino acids shown in Table 4 were synthesized according to the scheme shown below.

[0296]

[0297] Synthesis of compound aa3-001, (3S)-3-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-4-oxo-4-piperidin-1-ylbutanoic acid (Fmoc-MeAsp-pip) Compound aa3-001 was synthesized according to the method described in WO2018 / 225864.

[0298] Synthesis of compound aa3-002, (3S)-4-(dimethylamino)-3-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-4-oxobutanoic acid (Fmoc-MeAsp-NMe2) Using compound aa2-006-a (32.0 g, 73.3 mmol) as the starting material, compound aa3-002 was obtained as pale brown amorphous crystals (25.1 g, 86% yield) in the same manner as compound aa2-001. LCMS (ESI) m / z = 397.2 (M+H) + Retention time: 0.68 minutes (Analysis conditions SQDFA05)

[0299] Synthesis of compound aa3-003, Fmoc-Asp-NMe2

[0300] Synthesis of compound aa3-003-a, (3S)-4-(dimethylamino)-3-(9H-fluoren-9-ylmethoxycarbonylamino)-4-oxobutanoate-2-methylpropan-2-yl (Fmoc-Asp(OtBu)-NMe2) Starting from Fmoc-Asp(OtBu)-OH (25.0 g, 60.8 mmol) purchased from a commercial supplier, the synthesis of compound aa3-003-a was carried out in a similar manner to that of compound aa2-006-a to afford 29.8 g of crude compound aa3-003-a. LCMS (ESI) m / z = 461.3 (M+Na). + Retention time: 0.88 minutes (Analysis conditions SQDFA05)

[0301] Synthesis of compound aa3-003, (3S)-4-(dimethylamino)-3-(9H-fluoren-9-ylmethoxycarbonylamino)-4-oxobutanoic acid (Fmoc-Asp-NMe2) The crude product of compound aa3-003-a (29.8 g) and TFE (270 mL) were added to a reaction vessel, followed by the dropwise addition of 4 mol / L hydrochloric acid in dioxane (15.2 mL, 60.8 mmol). The reaction mixture was stirred at room temperature for 1 hour. The reaction mixture was diluted with TBME (500 mL) and extracted with 5% aqueous sodium carbonate (600 mL). The resulting aqueous layer was acidified to approximately pH 2-3 with 85% aqueous phosphoric acid (40-50 mL), and the aqueous layer was extracted with TBME (400 mL). The resulting organic layer was washed with 10% aqueous sodium chloride (400 mL) and water (400 mL), and then dried over sodium sulfate. The drying agent was removed by filtration, and the filtrate was concentrated under reduced pressure to give compound aa3-003 (21.4 g, 92% yield). LCMS (ESI) m / z = 383.2 (M+H). + Retention time: 0.66 minutes (Analysis conditions SQDFA05)

[0302] Examples 1-4. Synthesis of amino acid and peptide-supported resins In this specification, when a compound is bonded to a polymer or resin, the polymer or resin site may be represented by a circle. Furthermore, to clarify the reactive site of the resin site, the chemical structure of the reactive site may be represented by connecting it to a circle. For example, in the above structure, Fmoc-MeAsp(O-Trt(2-Cl)resin)-pip, the 2-chlorotrityl group of the resin is bonded to the side chain carboxylic acid of MeAsp via an ester bond. In Fmoc-MeAsp(NH-Sieber resin)-pip, the 9H-xanthene-9-amino group of the resin is bonded to the side chain carboxylic acid of MeAsp via an amide bond. Note that pip refers to piperidine, and in the above structure, the C-terminal carboxylic acid group forms an amide bond with the piperidine. 2-Chlorotrityl chloride resin (1.25-1.69 mmol / g, 100-200 mesh, 1% DVB) was purchased from Watanabe Chemical Industry Co., Ltd. and SUNRESIN, and Fmoc-NH-Sieber resin (0.69 mmol / g, 100-200 mesh, 1% DVB) was purchased from Novabiochem.

[0303] The Fmoc-amino acid or peptide-supported resins shown in Table 5 were synthesized according to the scheme shown below.

[0304]

[0305] Synthesis of compound aa2-001-resin, (3S)-3-[[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-3-methylbutanoyl]-methylamino]-4-oxo-4-piperidin-1-ylbutanoate-2-chlorotrityl resin (Fmoc-MeVal-MeAsp(O-Trt(2-Cl)resin)-pip) 2-Chlorotrityl chloride resin (1.25 mmol / g, 3.10 g, 3.87 mmol) and DCM (21.7 mL) were placed in a filter-equipped reaction vessel and shaken at room temperature for 45 minutes. After removing the DCM under nitrogen pressure, a mixture of compound aa2-001 (1.06 g, 1.94 mmol), methanol (0.627 mL, 15.5 mmol), and DIPEA (1.62 mL, 9.29 mmol) with DCM (to a total volume of 21.7 mL) was added to the reaction vessel and shaken at room temperature for 60 minutes. After removing the reaction solution under nitrogen pressure, a mixture of methanol (4.39 mL, 108 mmol), DIPEA (1.62 mL, 9.29 mmol), and DCM (to a total volume of 21.7 mL) was added to the reaction vessel and shaken at room temperature for 90 minutes. After removing the reaction solution under nitrogen pressure, DCM (21.7 mL) was added and the mixture was shaken for 5 minutes, after which the reaction solution was removed under nitrogen pressure. This DCM washing procedure was repeated five times, and the resulting resin was dried overnight under reduced pressure to obtain 3.58 g of aa2-001-resin.

[0306] Fmoc quantification: To confirm the loading amount, the resulting aa2-001-resin (11.94 mg) was placed in a reaction vessel, DMF (4.0 mL) was added, and the mixture was shaken at room temperature for 30 minutes. Then, DBU (40 μL) was added and the mixture was shaken at 30°C for 15 minutes. DMF was then added to the reaction mixture to make a 10.0 mL solution, and 80 μL of the resulting solution was diluted with DMF (920 μL). The diluted solution was analyzed by LC / MS (injection volume: 5 μL). Based on the UV area values ​​of dibenzofulvene (294 nm: 4211.62, 304 nm: 3791.08), the loading amount of aa2-001-resin was calculated to be 0.363 mmol / g. (A calibration curve was prepared on each measurement day based on the UV area values ​​of dibenzofulvene at wavelengths of 294 nm and 304 nm, using a mixed solution of Fmoc-Gly-OH (purchased from a commercial supplier) and DBU of known concentrations as the standard substance, and the average of the loading amounts calculated at each wavelength was taken as the loading amount on the resin.)

[0307] Synthesis of compound aa2-002-resin, (3S)-3-[[(2S,3S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-3-methylpentanoyl]-methylamino]-4-oxo-4-piperidin-1-ylbutanoate-2-chlorotrityl resin (Fmoc-MeIle-MeAsp(O-Trt(2-Cl)resin)-pip) Using 2-chlorotrityl chloride resin (1.25 mmol / g, 2.98 g, 3.72 mmol) and compound aa2-002 (1.05 g, 1.86 mmol) as starting materials, 3.54 g of compound aa2-002-resin was obtained using a method similar to that used for the synthesis of compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (10.47 mg) to be 0.326 mmol / g (UVarea value at 294 nm: 3648.96, UVarea value at 304 nm: 3280.91).

[0308] Synthesis of compound aa2-003-resin, (3S)-3-[[(2S)-2-cyclopentyl-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]acetyl]-methylamino]-4-oxo-4-piperidin-1-ylbutanoate-2-chlorotrityl resin (Fmoc-MeGly(cPent)-MeAsp(O-Trt(2-Cl)resin)-pip) Using 2-chlorotrityl chloride resin (1.25 mmol / g, 3.11 g, 3.88 mmol) and compound aa2-003 (1.12 g, 1.94 mmol) as starting materials, 3.73 g of compound aa2-003-resin was obtained using a method similar to that used for the synthesis of compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (11.34 mg) to be 0.362 mmol / g (UVarea value at 294 nm: 3979.93, UVarea value at 304 nm: 3588.46).

[0309] Synthesis of compound aa2-004-resin, (3S)-3-[[(2S)-2-cyclohexyl-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]acetyl]-methylamino]-4-oxo-4-piperidin-1-ylbutanoate-2-chlorotrityl resin (Fmoc-MeChg-MeAsp(O-Trt(2-Cl)resin)-pip) Using 2-chlorotrityl chloride resin (1.25 mmol / g, 2.57 g, 3.22 mmol) and compound aa2-004 (0.949 g, 1.61 mmol) as starting materials, 3.07 g of compound aa2-004-resin was obtained using a method similar to that for compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (10.09 mg) to be 0.347 mmol / g (UVarea value at 294 nm: 3412.72, UVarea value at 304 nm: 3069.21).

[0310] Synthesis of compound aa2-005-resin, (3S)-3-[[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-4-methylpentanoyl]-methylamino]-4-oxo-4-piperidin-1-ylbutanoate-2-chlorotrityl resin (Fmoc-MeLeu-MeAsp(O-Trt(2-Cl)resin)-pip) Using 2-chlorotrityl chloride resin (1.25 mmol / g, 3.09 g, 3.86 mmol) and compound aa2-005 (1.09 g, 1.93 mmol) as starting materials, 3.57 g of compound aa2-005-resin was obtained using a method similar to that used for the synthesis of compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (10.42 mg) to be 0.355 mmol / g (UVarea value at 294 nm: 3592.54, UVarea value at 304 nm: 3232.59).

[0311] Synthesis of compound aa2-006-resin, (3S)-3-[[(2S)-2-cyclopentyl-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]acetyl]-methylamino]-4-(dimethylamino)-4-oxobutanoate-2-chlorotrityl resin (Fmoc-MeGly(cPent)-MeAsp(O-Trt(2-Cl)resin)-NMe2). Starting from 2-chlorotrityl chloride resin (1.25 mmol / g, 2.35 g, 2.94 mmol) and compound aa2-006 (0.786 g, 1.47 mmol), compound aa2-006-resin (2.72 g) was obtained using a similar method to the synthesis of compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (11.77 mg) to be 0.345 mmol / g (UVarea value at 294 nm: 3965.86, UVarea value at 304 nm: 3566.11).

[0312] Synthesis of compound aa2-007-resin, (3S)-4-(dimethylamino)-3-[[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-4-methylpentanoyl]-methylamino]-4-oxobutanoate-2-chlorotrityl resin (Fmoc-MeLeu-MeAsp(O-Trt(2-Cl)resin)-NMe2) Using 2-chlorotrityl chloride resin (1.25 mmol / g, 3.04 g, 3.80 mmol) and compound aa2-007 (0.995 g, 1.90 mmol) as starting materials, 3.51 g of compound aa2-007-resin was obtained using a method similar to that used for the synthesis of compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (10.88 mg) to be 0.384 mmol / g (UVarea value at 294 nm: 4057.77, UVarea value at 304 nm: 3645.68).

[0313] Synthesis of compound aa2-008-resin, (3R)-3-[[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-3-methylbutanoyl]-methylamino]butanoate-2-chlorotrityl resin (Fmoc-MeVal-D-3-MeAbu-O-Trt(2-Cl)resin) Using 2-chlorotrityl chloride resin (1.25 mmol / g, 2.15 g, 2.68 mmol) and compound aa2-008 (0.607 g, 1.34 mmol) as starting materials, 2.47 g of compound aa2-008-resin was obtained using a method similar to that used for the synthesis of compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (11.13 mg) to be 0.415 mmol / g (UVarea value at 294 nm: 4513.80, UVarea value at 304 nm: 4054.24).

[0314] Synthesis of compound aa2-009-resin, (3R)-3-[[(2S)-2-cyclohexyl-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]acetyl]-methylamino]butanoate-2-chlorotrityl resin (Fmoc-MeChg-D-3-MeAbu-O-Trt(2-Cl)resin) Using 2-chlorotrityl chloride resin (1.25 mmol / g, 1.62 g, 2.03 mmol) and compound aa2-009 (0.500 g, 1.02 mmol) as starting materials, 1.91 g of compound aa2-009-resin was obtained using a method similar to that used for the synthesis of compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (12.74 mg) to be 0.397 mmol / g (UVarea value at 294 nm: 4946.37, UVarea value at 304 nm: 4444.88).

[0315] Synthesis of compound aa2-010-resin, 2-[[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-3-methylbutanoyl]-methylamino]acetic acid-2-chlorotrityl resin (Fmoc-MeVal-MeGly-O-Trt(2-Cl)resin) Using 2-chlorotrityl chloride resin (1.25 mmol / g, 3.17 g, 3.96 mmol) and compound aa2-010 (0.841 g, 1.98 mmol) as starting materials, 3.49 g of compound aa2-010-resin was obtained using a method similar to that used for the synthesis of compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (11.25 mg) to be 0.374 mmol / g (UVarea value at 294 nm: 4080.46, UVarea value at 304 nm: 3686.94).

[0316] Synthesis of compound aa2-011-resin, (3S)-3-[[(2S)-2-cyclopentyl-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]acetyl]-methyl-amino]-4-morpholino-4-oxo-butanoate-2-chlorotrityl resin (Fmoc-MeGly(cPent)-MeAsp-(O-Trt(2-Cl)resin)-mor) A 400 mL reaction vessel equipped with a filter was charged with 2-chlorotrityl chloride resin (1.36 mmol / g, 20.5 g, 15.07 mmol) and DCM (140 mL) and allowed to stand at room temperature for 1 hour. After removing the DCM under nitrogen pressure, a solution of compound aa2-011 (9.50 g, 16.45 mmol), methanol (5.32 mL, 132 mmol), and DIPEA (13.8 mL, 79 mmol) in DCM (140 mL) was added to the reaction vessel and shaken at 25 °C and 60 rpm for 60 minutes. After removing the reaction mixture under nitrogen pressure, a solution of methanol (20 mL, 493 mmol) and DIPEA (13.8 mL, 79 mmol) in DCM (140 mL) was added to the reaction vessel and shaken at 25 °C and 60 rpm for 60 minutes. After removing the reaction solution under nitrogen pressure, DCM (140 mL) was added and mixed, followed by decanting under nitrogen pressure. This DCM washing procedure was repeated five times. The resulting resin was dried under reduced pressure for one day to obtain 26.89 g of compound aa2-011-resin. The amount of amino acid supported on the resin was calculated as follows. Compound aa2-011-resin (10 mg) was placed in a reaction vessel, DMF (2 mL) was added, and the mixture was left at room temperature for 1 hour. DBU (40 μL) was then added and the mixture was shaken at 25°C for 30 minutes. DMF (8 mL) was then added to the reaction mixture, and 1 mL of the resulting solution was diluted with DMF (11.5 mL). The absorbance (294 nm) of the diluted solution was measured using a Shimadzu UV-1600PC (cell length 1.0 cm), and the amount of compound aa2-011-resin supported was calculated to be 0.415 mmol / g.

[0317] Synthesis of compound aa2-012-resin, (3S)-4-(dimethylamino)-3-[[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-3-methylbutanoyl]amino]-4-oxobutanoate-2-chlorotrityl resin (Fmoc-MeVal-Asp(O-Trt(2-Cl)resin)-NMe2) Using 2-chlorotrityl chloride resin (1.25 mmol / g, 3.28 g, 4.10 mmol) and compound aa2-012 (1.02 g, 2.05 mmol) as starting materials, 3.73 g of compound aa2-012-resin was obtained using a method similar to that used for the synthesis of compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (12.55 mg) to be 0.373 mmol / g (UVarea value at 294 nm: 5042.25, UVarea value at 304 nm: 4531.21).

[0318] Synthesis of compound aa2-013-resin, (3S)-4-(dimethylamino)-3-[[2-(9H-fluoren-9-ylmethoxycarbonylamino)acetyl]-methylamino]-4-oxobutanoate-2-chlorotrityl resin (Fmoc-Gly-MeAsp(O-Trt(2-Cl)resin)-NMe2) Using 2-chlorotrityl chloride resin (1.25 mmol / g, 3.57 g, 4.46 mmol) and compound aa2-013 (1.01 g, 2.23 mmol) as starting materials, 3.98 g of compound aa2-013-resin was obtained using a method similar to that used for the synthesis of compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (12.33 mg) to be 0.386 mmol / g (UVarea value at 294 nm: 5134.21, UVarea value at 304 nm: 4593.14).

[0319] Synthesis of compound aa2-014-resin, (3S)-4-(dimethylamino)-3-[[2-(9H-fluoren-9-ylmethoxycarbonylamino)-2-methylpropanoyl]-methylamino]-4-oxobutanoate-2-chlorotrityl resin (Fmoc-Aib-MeAsp(O-Trt(2-Cl)resin)-NMe2) Using 2-chlorotrityl chloride resin (1.25 mmol / g, 3.46 g, 4.32 mmol) and compound aa2-014 (1.04 g, 2.16 mmol) as starting materials, 3.96 g of compound aa2-014-resin was obtained using a method similar to that used for the synthesis of compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (10.22 mg) to be 0.413 mmol / g (UVarea value at 294 nm: 4205.24, UVarea value at 304 nm: 3774.43).

[0320] Synthesis of compound aa2-015-resin, (3R)-3-[[3-(9H-fluoren-9-ylmethoxycarbonylamino)-2,2-dimethylpropanoyl]-methylamino]butanoate-2-chlorotrityl resin (Fmoc-bAla(2-Me2)-D-3-MeAbu-O-Trt(2-Cl)resin) Using 2-chlorotrityl chloride resin (1.25 mmol / g, 1.02 g, 1.28 mmol) and compound aa2-015 (281 mg, 0.640 mmol) as starting materials, 1.14 g of compound aa2-015-resin was obtained using a method similar to that used for the synthesis of compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (10.46 mg) to be 0.443 mmol / g (UVarea value at 294 nm: 4615.90, UVarea value at 304 nm: 4143.20).

[0321] Synthesis of compound aa2-016-resin, (2S)-2-[[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-4-methylpentanoyl]-methylamino]-3-methylbutanoate-2-chlorotrityl resin (Fmoc-MeLeu-MeVal-O-Trt(2-Cl)resin) Starting from 2-chlorotrityl chloride resin (1.25 mmol / g, 617 mg, 0.771 mmol) and compound aa2-016 (185 mg, 0.386 mmol), 663 mg of compound aa2-016-resin was obtained using a method similar to that used for the synthesis of compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (12.18 mg) to be 0.348 mmol / g (UVarea value at 294 nm: 4325.21, UVarea value at 304 nm: 3876.60).

[0322] Synthesis of compound aa2-017-resin, (2S)-1-[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-3-methylbutanoyl]pyrrolidine-2-carboxylate-2-chlorotrityl resin (Fmoc-MeVal-Pro-O-Trt(2-Cl)resin) Using 2-chlorotrityl chloride resin (1.25 mmol / g, 4.79 g, 5.99 mmol) and compound aa2-017 (1.35 g, 3.00 mmol) as starting materials, 5.40 g of compound aa2-017-resin was obtained using a method similar to that used for the synthesis of compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (10.38 mg) to be 0.364 mmol / g (UVarea value at 294 nm: 3850.10, UVarea value at 304 nm: 3472.31).

[0323] Synthesis of compound aa2-018-resin, 2-[[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-4-methylpentanoyl]amino]-2-methylpropanoic acid-2-chlorotrityl resin (Fmoc-MeLeu-Aib-O-Trt(2-Cl)resin) Using 2-chlorotrityl chloride resin (1.25 mmol / g, 2.15 g, 2.69 mmol) and compound aa2-018 (608 mg, 1.34 mmol) as starting materials, 2.29 g of compound aa2-018-resin was obtained using a method similar to that used for the synthesis of compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (9.61 mg) to be 0.300 mmol / g (UVarea value at 294 nm: 2934.11, UVarea value at 304 nm: 2651.64).

[0324] Synthesis of compound aa2-019-resin, 2-[[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-3-methylbutanoyl]amino]acetic acid-2-chlorotrityl resin (Fmoc-MeVal-Gly-O-Trt(2-Cl)resin) Using 2-chlorotrityl chloride resin (1.25 mmol / g, 5.11 g, 6.38 mmol) and compound aa2-019 (1.31 g, 3.19 mmol) as starting materials, compound aa2-019-resin (5.46 g) was obtained using a method similar to that used for the synthesis of compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (10.73 mg) to be 0.303 mmol / g (UVarea value at 294 nm: 3312.44, UVarea value at 304 nm: 2987.09).

[0325] Synthesis of compound aa2-020-resin, (3S)-4-(dimethylamino)-3-[[(2R)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-3-methylbutanoyl]-methylamino]-4-oxobutanoate-2-chlorotrityl resin (Fmoc-D-MeVal-MeAsp(O-Trt(2-Cl)resin)-NMe2). Using 2-chlorotrityl chloride resin (1.25 mmol / g, 3.77 g, 4.71 mmol) and compound aa2-020 (1.20 g, 2.36 mmol) as starting materials, compound aa2-020-resin (4.47 g) was obtained using a method similar to that used for the synthesis of compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (11.75 mg) to be 0.396 mmol / g (UVarea value at 294 nm: 4635.95, UVarea value at 304 nm: 4167.33).

[0326] Synthesis of compound aa2-021-resin, (3S)-4-(dimethylamino)-3-[[3-(9H-fluoren-9-ylmethoxycarbonylamino)-2,2-dimethylpropanoyl]-methylamino]-4-oxobutanoate-2-chlorotrityl resin (Fmoc-bAla(2-Me2)-MeAsp(O-Trt(2-Cl)resin)-NMe2). Using 2-chlorotrityl chloride resin (1.25 mmol / g, 2.82 g, 3.53 mmol) and compound aa2-021 (874 mg, 1.76 mmol) as starting materials, 3.24 g of compound aa2-021-resin was obtained using a method similar to that used for the synthesis of compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (9.82 mg) to be 0.407 mmol / g (UVarea value at 294 nm: 3979.96, UVarea value at 304 nm: 3574.96).

[0327] Synthesis of compound aa2-022-resin, (3R)-4-(dimethylamino)-3-[[(2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-3-methylbutanoyl]-methylamino]-4-oxobutanoate-2-chlorotrityl resin (Fmoc-MeVal-D-MeAsp(O-Trt(2-Cl)resin)-NMe2). Using 2-chlorotrityl chloride resin (1.25 mmol / g, 3.97 g, 4.96 mmol) and compound aa2-022 (1.26 g, 2.48 mmol) as starting materials, 4.75 g of compound aa2-022-resin was obtained using a method similar to that used for the synthesis of compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (10.79 mg) to be 0.396 mmol / g (UVarea value at 294 nm: 4264.54, UVarea value at 304 nm: 3819.26).

[0328] Synthesis of compound aa2-023-resin, (3S)-3-[[(2S)-2-cyclopentyl-2-[[(2S)-2-(9H-fluoren-9-ylmethoxycarbonylamino)propanoyl]-methylamino]acetyl]-methylamino]-4-(dimethylamino)-4-oxobutanoate-2-chlorotrityl resin (Fmoc-Ala-MeGly(cPent)-MeAsp(O-Trt(2-Cl)resin)-NMe2). Using 2-chlorotrityl chloride resin (1.25 mmol / g, 700 mg, 0.875 mmol) and compound aa2-023 (265 mg, 0.437 mmol) as starting materials, 801 mg of compound aa2-023-resin was obtained using a method similar to that used for the synthesis of compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (9.35 mg) to be 0.378 mmol / g (UVarea value at 294 nm: 3477.62, UVarea value at 304 nm: 3130.63).

[0329] Synthesis of compound aa2-024-resin, (2S)-1-[(2S)-2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-phenylpropanoyl]pyrrolidine-2-carboxylic acid-2-chlorotrityl resin (Fmoc-Phe-Pro-O-Trt(2-Cl)resin) Using 2-chlorotrityl chloride resin (1.25 mmol / g, 1.12 g, 1.40 mmol) and Fmoc-Phe-Pro-OH (339 mg, 0.700 mmol) as starting materials, 1.23 g of compound aa2-024-resin was obtained using a method similar to that used for compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (9.62 mg) to be 0.383 mmol / g (UVarea value at 294 nm: 3782.71, UVarea value at 304 nm: 3403.88).

[0330] Synthesis of compound aa2-025-resin, (2S)-1-[(2S)-2-(9H-fluoren-9-ylmethoxycarbonylamino)-6-[(2-methylpropan-2-yl)oxycarbonylamino]hexanoyl]pyrrolidine-2-carboxylate-2-chlorotrityl resin (Fmoc-Lys(Boc)-Pro-O-Trt(2-Cl)resin) Using 2-chlorotrityl chloride resin (1.25 mmol / g, 1.12 g, 1.40 mmol) and Fmoc-Lys(Boc)-Pro-OH (396 mg, 0.700 mmol) as starting materials, 1.24 g of compound aa2-025-resin was obtained using a method similar to that used for compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (11.50 mg) to be 0.339 mmol / g (UVarea value at 294 nm: 4200.46, UVarea value at 304 nm: 3772.96).

[0331] Synthesis of compound aa2-026-resin, (2S)-2-[[2-(9H-fluoren-9-ylmethoxycarbonylamino)acetyl]amino]-3-[4-[(2-methylpropan-2-yl)oxy]phenyl]propanoic acid-2-chlorotrityl resin (Fmoc-Gly-Tyr(tBu)-O-Trt(2-Cl)resin) Using 2-chlorotrityl chloride resin (1.25 mmol / g, 1.12 g, 1.40 mmol) and Fmoc-Gly-Tyr(tBu)-OH (362 mg, 0.700 mmol) as starting materials, 1.15 g of compound aa2-026-resin was obtained using a method similar to that used for compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (9.88 mg) to be 0.244 mmol / g (UVarea value at 294 nm: 2478.91, UVarea value at 304 nm: 2222.03).

[0332] Synthesis of compound aa2-027-resin, (2S)-2-[[(2S)-2-(9H-fluoren-9-ylmethoxycarbonylamino)propanoyl]amino]propanoic acid-2-chlorotrityl resin (Fmoc-Ala-Ala-O-Trt(2-Cl)resin) Using 2-chlorotrityl chloride resin (1.25 mmol / g, 1.28 g, 1.60 mmol) and Fmoc-Ala-Ala-OH (306 mg, 0.800 mmol) as starting materials, 1.39 g of compound aa2-027-resin was obtained using a method similar to that used for the synthesis of compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (9.69 mg) to be 0.334 mmol / g (UVarea value at 294 nm: 3496.53, UVarea value at 304 nm: 3128.64).

[0333] Synthesis of compound aa2-028-resin, 2-[[(2S)-2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-phenylpropanoyl]amino]acetic acid-2-chlorotrityl resin (Fmoc-Phe-Gly-O-Trt(2-Cl)resin) Using 2-chlorotrityl chloride resin (1.25 mmol / g, 1.28 g, 1.60 mmol) and Fmoc-Phe-Gly-OH (356 mg, 0.800 mmol) as starting materials, 1.36 g of compound aa2-028-resin was obtained using a method similar to that used for the synthesis of compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (10.12 mg) to be 0.248 mmol / g (UVarea value at 294 nm: 2703.55, UVarea value at 304 nm: 2442.89).

[0334] Synthesis of compound aa2-029-resin, 2-[[(2S)-2-(9H-fluoren-9-ylmethoxycarbonylamino)-4-oxo-4-(tritylamino)butanoyl]amino]acetic acid-2-chlorotrityl resin (Fmoc-Asn(Trt)-Gly-O-Trt(2-Cl)resin) Using 2-chlorotrityl chloride resin (1.25 mmol / g, 1.12 g, 1.40 mmol) and Fmoc-Asn(Trt)-Gly-OH (458 mg, 0.700 mmol) as starting materials, 1.15 g of compound aa2-029-resin was obtained using a method similar to that used for compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (9.67 mg) to be 0.259 mmol / g (UVarea value at 294 nm: 2698.79, UVarea value at 304 nm: 2427.13).

[0335] Synthesis of compound aa2-030-resin, (2S)-2-[[2-(9H-fluoren-9-ylmethoxycarbonylamino)acetyl]amino]-3-methylbutanoate-2-chlorotrityl resin (Fmoc-Gly-Val-O-Trt(2-Cl)resin) Using 2-chlorotrityl chloride resin (1.25 mmol / g, 1.28 g, 1.60 mmol) and Fmoc-Gly-Val-OH (317 mg, 0.800 mmol) as starting materials, 1.38 g of compound aa2-030-resin was obtained using a method similar to that used for the synthesis of compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (10.06 mg) to be 0.278 mmol / g (UVarea value at 294 nm: 3013.51, UVarea value at 304 nm: 2712.54).

[0336] Synthesis of compound aa2-031-resin, 2-[[(2S)-2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-[(2-methylpropan-2-yl)oxy]propanoyl]amino]acetic acid-2-chlorotrityl resin (Fmoc-Ser(tBu)-Gly-O-Trt(2-Cl)resin) Using 2-chlorotrityl chloride resin (1.25 mmol / g, 1.12 g, 1.40 mmol) and Fmoc-Ser(tBu)-Gly-OH (308 mg, 0.700 mmol) as starting materials, 1.10 g of compound aa2-031-resin was obtained using a method similar to that used for compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (10.35 mg) to be 0.258 mmol / g (UVarea value at 294 nm: 2884.14, UVarea value at 304 nm: 2584.43).

[0337] Synthesis of compound aa2-032-resin, (2S)-1-[(2S)-2-[[(2S)-2-(9H-fluoren-9-ylmethoxycarbonylamino)propanoyl]amino]propanoyl]pyrrolidine-2-carboxylate-2-chlorotrityl resin (Fmoc-Ala-Ala-Pro-O-Trt(2-Cl)resin) Using 2-chlorotrityl chloride resin (1.25 mmol / g, 1.12 g, 1.40 mmol) and Fmoc-Ala-Ala-Pro-OH (336 mg, 0.700 mmol) as starting materials, 1.24 g of compound aa2-032-resin was obtained using a method similar to that used for compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (11.15 mg) to be 0.393 mmol / g (UVarea value at 294 nm: 4495.05, UVarea value at 304 nm: 4047.48).

[0338] Synthesis of compound aa3-001-resin, (3S)-3-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-4-oxo-4-piperidin-1-ylbutanoate-2-chlorotrityl resin (Fmoc-MeAsp(O-Trt(2-Cl)resin)-pip) Starting from 2-chlorotrityl chloride resin (1.44 mmol / g, 44.5 g, 64.1 mmol) and compound aa3-001 (14.0 g, 32.1 mmol), 52.7 g of compound aa3-001-resin was obtained using a method similar to that for compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (11.29 mg) to be 0.455 mmol / g (UVarea value at 294 nm: 5277.47, UVarea value at 304 nm: 4746.13).

[0339] Synthesis of compound aa3-002-resin, (3S)-4-(dimethylamino)-3-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-4-oxobutanoate-2-chlorotrityl resin (Fmoc-MeAsp(O-Trt(2-Cl)resin)-NMe2) Using 2-chlorotrityl chloride resin (1.60 mmol / g, 8.83 g, 14.1 mmol) and compound aa3-002 (2.80 g, 7.06 mmol) as starting materials, 10.4 g of compound aa3-002-resin was obtained using a method similar to that used for the synthesis of compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (11.04 mg) to be 0.442 mmol / g (UVarea value at 294 nm: 4990.63, UVarea value at 304 nm: 4516.89).

[0340] Synthesis of compound aa3-003-resin, (3S)-4-(dimethylamino)-3-(9H-fluoren-9-ylmethoxycarbonylamino)-4-oxobutanoate-2-chlorotrityl resin (Fmoc-Asp(O-Trt(2-Cl)resin)-NMe2) Using 2-chlorotrityl chloride resin (1.44 mmol / g, 39.0 g, 56.2 mmol) and compound aa3-003 (10.7 g, 28.0 mmol) as starting materials, 45.0 g of compound aa3-003-resin was obtained using a method similar to that used for the synthesis of compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (10.48 mg) to be 0.469 mmol / g (UVarea value at 294 nm: 4929.82, UVarea value at 304 nm: 4428.76).

[0341] Synthesis of compound aa4-001-resin, (3R)-3-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]butanoate-2-chlorotrityl resin (Fmoc-D-3-MeAbu-O-Trt(2-Cl)resin) 2-Chlorotrityl chloride resin (1.60 mmol / g, 25.0 g, 40.0 mmol) and DCM (125 mL) were placed in a filter-equipped reaction vessel and shaken at room temperature for 20 min. After removing the DCM under nitrogen pressure, a mixture of Fmoc-D-3-MeAbu-OH (3.60 g, 10.6 mmol), methanol (0.859 mL, 21.2 mmol), and DIPEA (12.3 mL, 70.7 mmol) with DCM (total volume: 145 mL) was added to the reaction vessel and shaken at room temperature for 30 min. After removing the reaction mixture under nitrogen pressure, a mixture of methanol (12.5 mL, 143 mmol), DIPEA (12.5 mL, 71.8 mmol), and DCM (total volume: 250 mL) was added to the reaction vessel and shaken at room temperature for 90 min. After applying nitrogen pressure to remove the reaction mixture, DCM (180 mL) was added and the mixture was shaken for 5 minutes, after which the reaction mixture was removed by applying nitrogen pressure. The resin was washed with DCM three times, and the resulting resin was dried overnight under reduced pressure to obtain 28.3 g of aa4-001-resin. The loading amount was calculated using the Fmoc quantification method using the dried resin (10.36 mg) to be 0.369 mmol / g (UVarea value at 294 nm: 3920.38, UVarea value at 304 nm: 3530.84).

[0342] Synthesis of compound aa4-002-resin, 2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]acetic acid-2-chlorotrityl resin (Fmoc-MeGly-O-Trt(2-Cl)resin) 2-Chlorotrityl chloride resin (1.60 mmol / g, 12.3 g, 19.7 mmol) and DCM (125 mL) were placed in a filter-equipped reaction vessel and shaken at room temperature for 20 minutes. After removing the DCM under nitrogen pressure, a mixture of Fmoc-MeGly-OH (3.07 g, 9.87 mmol), DIPEA (8.25 mL, 47.4 mmol), and DCM (110 mL) was added to the reaction vessel and shaken at room temperature for 60 minutes. After removing the reaction mixture under nitrogen pressure, a mixture of methanol (12.8 mL, 316 mmol), DIPEA (8.25 mL, 47.4 mmol), and DCM (110 mL) was added to the reaction vessel and shaken at room temperature for 90 minutes. After removing the reaction mixture under nitrogen pressure, DCM (180 mL) was added and shaken for 5 minutes, followed by removing the reaction mixture under nitrogen pressure. This resin washing procedure with DCM was repeated twice, and the resulting resin was dried under reduced pressure overnight to obtain 22.2 g of compound aa4-002-resin. The loading amount was calculated using the Fmoc quantification method using the dried resin (10.00 mg) to be 0.573 mmol / g (UVarea value at 294 nm: 5879.66, UVarea value at 304 nm: 5289.40).

[0343] Synthesis of compound aa4-003-resin, (2S)-2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]-3-methylbutanoate-2-chlorotrityl resin (Fmoc-MeVal-O-Trt(2-Cl)resin) Using 2-chlorotrityl chloride resin (1.25 mmol / g, 3.03 g, 3.79 mmol) and Fmoc-MeVal-OH (669 mg, 1.89 mmol) as starting materials, 3.37 g of compound aa4-003-resin was obtained using a method similar to that used for compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (10.21 mg) to be 0.436 mmol / g (UVarea value at 294 nm: 4751.39, UVarea value at 304 nm: 4274.97).

[0344] Synthesis of compound aa4-004-resin, (2S)-pyrrolidine-1,2-dicarboxylic acid 1-O-(9H-fluoren-9-ylmethyl) 2-O-2-chlorotrityl resin (Fmoc-Pro-O-Trt(2-Cl)resin) Using 2-chlorotrityl chloride resin (1.69 mmol / g, 25.0 g, 42.3 mmol) and Fmoc-Pro-OH (7.13 mg, 21.1 mmol) as starting materials, 28.8 g of compound aa4-004-resin was obtained using a similar method to that used for compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (10.87 mg) to be 0.432 mmol / g (UVarea value at 294 nm: 4714.30, UVarea value at 304 nm: 4225.61).

[0345] Synthesis of compound aa4-005-resin, 2-(9H-fluoren-9-ylmethoxycarbonylamino)-2-methylpropanoic acid-2-chlorotrityl resin (Fmoc-Aib-O-Trt(2-Cl) resin) Using 2-chlorotrityl chloride resin (1.25 mmol / g, 3.15 g, 3.93 mmol) and Fmoc-Aib-OH (640 mg, 1.97 mmol) as starting materials, 3.41 g of compound aa4-005-resin was obtained using a similar method to that used for compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (10.43 mg) to be 0.390 mmol / g (UVarea value at 294 nm: 4336.95, UVarea value at 304 nm: 3918.58).

[0346] Synthesis of compound aa4-006-resin, 2-(9H-fluoren-9-ylmethoxycarbonylamino)acetic acid-2-chlorotrityl resin (Fmoc-Gly-O-Trt(2-Cl) resin) Using 2-chlorotrityl chloride resin (1.25 mmol / g, 2.40 g, 3.00 mmol) and Fmoc-Gly-OH (446 mg, 1.50 mmol) as starting materials, 2.39 g of compound aa4-006-resin was obtained using a method similar to that used for compound aa2-001-resin. The loading amount was calculated using the Fmoc quantification method using dried resin (10.06 mg) to be 0.250 mmol / g (UVarea value at 294 nm: 2563.25, UVarea value at 304 nm: 2311.09).

[0347] Synthesis of compound aa5-001-resin, N-[(2S)-1-[[(2S)-4-[(Sieber resin)amino]-1,4-dioxo-1-piperidin-1-ylbutan-2-yl]-methylamino]-3-methyl-1-oxobutan-2-yl]-N-methylcarbamate 9H-fluoren-9-ylmethyl (Fmoc-MeVal-MeAsp(NH-Sieber resin)-pip) Fmoc-NH-Sieber resin (0.69 mmol / g, 600 mg, 0.414 mmol) was placed in a solid-phase reaction vessel equipped with a filter (frit). DCM (7.2 mL) was added and allowed to stand for 30 minutes to allow the resin to swell, after which the solution was drained through the frit. A solution of DBU in DMF (2% v / v, 4.2 mL) was added to the solid-phase reaction vessel containing the resin and allowed to react for 4.5 minutes at room temperature to remove the Fmoc group. The solution was then drained through the frit. DMF (4.2 mL) was added, allowed to stand for 5 minutes, and the solution was drained through the frit. This resin washing process was repeated three more times. Next, compound aa2-001 (594 mg, 1.08 mmol) was mixed with a solution of HOAt (92 mg, 0.676 mmol) in NMP (1.80 mL) and a solution of DIC (192 mg, 1.52 mmol) in DMF (2.16 mL) and then added to the resin. The solid-phase reaction vessel was heated to 40 °C and allowed to react for 2.5 h. The reaction mixture was then poured through a frit. The resin was then washed four times with DMF (4.2 mL) and five times with DCM (4.2 mL). The resulting resin was dried overnight under reduced pressure to yield 688 mg of compound aa5-001-resin. The loading of the dried resin (11.46 mg) was calculated to be 0.538 mmol / g using the Fmoc quantitation method. (UVarea value at 294 nm: 6072.34, UVarea value at 304 nm: 5457.70)

[0348] Example 2 Comparative experiment of peptide recovery rate and purity when a dipeptide is supported and when a single amino acid is supported in solid-phase peptide synthesis In this example, a tripeptide represented by Fmoc-AA3-AA2-AA1-resin is synthesized by a solid-phase reaction using a peptide synthesizer under the following three conditions, and the recovery rate and purity are compared.

[0349]

[0350]

[0351] The solid-phase peptide synthesis described in this example was carried out by the Fmoc method using a peptide synthesizer (Multipep RS; manufactured by Intavis). Detailed procedures were described in the manual that came with the synthesizer.

[0352] Detailed synthesis conditions in Example 2 are shown in Synthesis Method 1 below.

[0353] Synthesis Method 1: Solution 1 was prepared by dissolving the Fmoc-protected amino acids (0.6 mol / L) constituting the target peptide and HOAt or oxyma (0.375 mol / L) as a carboxylic acid activator in NMP. When the Fmoc-protected amino acid was poorly soluble, DMSO was added to prepare Solution 1 at a concentration of 20-30% (v / v). Solution 2 was prepared by mixing the Fmoc-protected amino acid with DMF at a concentration of 10% (v / v). The resin (100 mg) carrying the Fmoc amino acid or peptide prepared in Examples 1-4 was placed in a solid-phase reaction vessel equipped with a filter (frit) and placed in a peptide synthesizer. After adding DCM (1.2 mL) and allowing to stand for 30 minutes to allow the resin to swell, the solution was removed from the frit. Solutions 1 and 2 were placed in the peptide synthesizer, and automated synthesis using the peptide synthesizer was initiated.

[0354] A DBU / DMF solution (2% v / v, 0.7 mL) was added to the solid-phase reaction vessel containing the resin, and the Fmoc group removal reaction was carried out at room temperature. The reaction was allowed to proceed for 4.5 minutes for the first deprotection and 10 minutes for the second and subsequent deprotection, after which the solution was drained through the frit. DMF (0.7 mL) was added, allowed to stand for 5 minutes, and then the solution was drained through the frit. This resin washing process was repeated three more times. Next, Solution 1 (0.3 mL) and Solution 2 (0.36 mL) were mixed in the synthesizer's mixing vial and added to the resin. The solid-phase reaction vessel was heated to 40°C or 50°C, and the reaction was continued for 2.5 or 10 hours, allowing the condensation reaction between the amino groups on the resin and the Fmoc-protected amino acid to proceed. The solution was then drained through the frit. The resin was then washed three times with DMF (0.7 mL). This Fmoc group removal reaction followed by the Fmoc amino acid condensation reaction constituted one cycle, and this cycle was repeated to elongate the peptide on the resin surface.

[0355] After peptide elongation was completed, the resulting resin was washed four times with DMF (0.7 mL), followed by four washes with DCM (0.7 mL), and air-dried for 48 hours at room temperature. A portion of the resulting resin (approximately 10 mg) was placed in a reaction vessel, and the amount of peptide loaded on the resin was calculated using the Fmoc quantification method described in Example 1-4. A portion of the resulting resin (approximately 20 mg) was also placed in a reaction vessel, and a TFE / DCM solution (1 / 1, 1 mL) with or without 0.75% (v / v) DIPEA was added. The mixture was shaken at room temperature for 2 hours to carry out the peptide cleavage reaction. After the reaction, the cleavage solution was analyzed by LCMS to confirm the presence of the product on the resin.

[0356] The definition and calculation method of the recovery rate in Example 2 are shown in the following recovery rate calculation method.

[0357] In Example 2, the recovery rate was defined as follows, and the rate of release of amino acids and peptides from the resin during the solid-phase reaction, in other words, the rate of inhibition of premature cleavage, was evaluated. Recovery rate = Amount of reaction product supported on resin (mmol / g) ÷ Amount of resin supported when 100% of the target product is produced (mmol / g) (Equation 1).

[0358] The amount of resin supported (mmol / g) when 100% of the target substance is produced is calculated as follows: Amount of resin supported (mmol / g) when 100% of the target substance is produced = Amount of starting resin supported (mmol / g) × Weight of starting resin (g) ÷ Weight of resin when 100% of the target substance is produced (g) (Equation 2)

[0359] The weight (g) of resin when 100% of the target product is produced is calculated as follows: Weight (g) of resin when 100% of the target product is produced = Weight (g) of starting resin - Weight (g) of amino acid or peptide component on starting resin + Weight (g) of peptide component on resin when 100% of the target product is produced (Equation 3)

[0360] The weight (g) of the amino acid or peptide component on the starting resin is calculated as follows: Weight (g) of the amino acid or peptide component on the starting resin = Weight (g) of the starting resin x Amount supported on the starting resin (mmol / g) x Molecular weight of the amino acid or peptide component on the starting resin (g / mol) x 0.001 (mol / mmol) (Equation 4).

[0361] The weight (g) of the peptide component on the resin when 100% of the target substance is produced is calculated as follows: Weight (g) of the peptide component on the resin when 100% of the target substance is produced = Weight (g) of the starting resin × Amount supported on the starting resin (mmol / g) × Molecular weight of the target peptide component (g / mol) × 0.001 (mol / mmol) (Equation 5)

[0362] Substituting Equation 3, Equation 4, and Equation 5 into Equation 2, Amount supported by resin when 100% of target substance is produced (mmol / g) = Amount supported by starting resin (mmol / g) ÷ (1 - Amount supported by starting resin (mmol / g) × Molecular weight of amino acid or peptide component on starting resin (g / mol) × 0.001 (mol / mmol) + Amount supported by starting resin (mmol / g) × Molecular weight of target peptide component (g / mol) × 0.001 (mol / mmol)) = 1 ÷ (1 ÷ Amount supported by starting resin (mmol / g) - Molecular weight of amino acid or peptide component on starting resin (g / mol) × 0.001 (mol / mmol) + Molecular weight of target peptide component (g / mol) × 0.001 (mol / mmol)) (Equation 6)

[0363] Substituting Equation 6 into Equation 1, the recovery rate can be calculated using the following formula: Recovery rate = Amount of reaction product supported on resin (mmol / g) × (1 ÷ Amount of starting resin supported (mmol / g) - Molecular weight of amino acid or peptide component on starting resin (g / mol) × 0.001 (mol / mmol) + Molecular weight of target peptide component (g / mol) × 0.001 (mol / mmol)).

[0364] Synthesis of compound pd2-001-resin, (3S)-3-[[(2S)-2-[[(2S,3S)-2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-methylpentanoyl]-methylamino]-3-methylbutanoyl]-methylamino]-4-oxo-4-piperidin-1-ylbutanoate-2-chlorotrityl resin (Fmoc-Ile-MeVal-MeAsp(O-Trt(2-Cl)resin)-pip) under synthesis condition 1.

[0365] Starting from the dipeptide-loaded resin aa2-001-resin (Fmoc-MeVal-MeAsp(O-Trt(2-Cl)resin)-pip) (100 mg, 0.363 mmol / g) prepared in Example 1-4, pd2-001-resin was synthesized by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours) according to Synthesis Method 1. The loading amount was calculated using the dried resin (11.36 mg) by Fmoc quantification to be 0.344 mmol / g (UVarea value at 294 nm: 3907.18, UVarea value at 304 nm: 3521.50).

[0366] The recovery rate was calculated using the following formula: Recovery rate = 0.344 × (1 ÷ 0.363 - 549.67 × 0.001 + 662.83 × 0.001) = 98.7%. LCMS analysis of the cleavage reaction mixture revealed that the purity of the target compound pd2-001 was 98.2 area%, with 1.8 area% of the epimer pd2-001-a. This epimer was an impurity that was already present in the preparation of compound aa2-001, and was not an impurity derived from the process of elongating AA3 (here, Ile).

[0367] Analysis conditions: SQDAA50long

[0368] Synthesis of pd2-001-resin under Condition 2. Starting from the amino acid-loaded resin aa3-001-resin (Fmoc-MeAsp(O-Trt(2-Cl)resin)-pip) (100 mg, 0.455 mmol / g) prepared in Example 1-4, pd2-001-resin was synthesized by following Synthesis Method 1, elongating the Fmoc-MeVal-OH (HOAt, 40°C, 2.5 hours) and then elongating the Fmoc-Ile-OH (HOAt, 40°C, 2.5 hours). The loading amount was calculated using the dried resin (10.45 mg) by Fmoc quantification to be 0.292 mmol / g (UVarea value at 294 nm: 3046.82, UVarea value at 304 nm: 2746.87).

[0369] The recovery rate was calculated using the following formula: Recovery rate = 0.292 × (1 ÷ 0.455 - 436.51 × 0.001 + 662.83 × 0.001) = 70.8%. LCMS analysis of the cleavage reaction mixture revealed that the purity of the target product pd2-001 was 61.6 area%, with the epimer pd2-001-a at 6.5 area%, the over-extended product pd2-001-b at 2.4 area%, and the AA2 deletion product pd2-001-c at 29.5 area%. Here, over-elongated product pd2-001-b refers to a compound in which AA1 (here, MeAsp-pip) is detached from the resin during the elongation of AA2 (here, MeVal), and the detached AA1 is elongated relative to the AA1 supported on the resin, i.e., a compound in which two AA1s are bonded, and then AA2 and AA3 are elongated. Unless otherwise specified, in the following examples, over-elongated product refers to a compound in which two AA1s are bonded.

[0370] Analysis conditions: SQDAA50long

[0371] Synthesis of pd2-001-resin under Condition 3. Starting from the amino acid-loaded resin aa3-001-resin (Fmoc-MeAsp(O-Trt(2-Cl)resin)-pip) (100 mg, 0.455 mmol / g) prepared in Example 1-4, pd2-001-resin was synthesized by extending the Fmoc-MeVal-OH (oxyma, 50°C, 10 hours) and then extending the Fmoc-Ile-OH (HOAt, 40°C, 2.5 hours) according to Synthesis Method 1. The loading amount was calculated using the dried resin (10.89 mg) by Fmoc quantification to be 0.332 mmol / g (UVarea value at 294 nm: 3612.81, UVarea value at 304 nm: 3267.35).

[0372] The recovery rate was calculated using the following formula: Recovery rate = 0.332 × (1 ÷ 0.455 - 436.51 × 0.001 + 662.83 × 0.001) = 80.5%. LCMS analysis of the cleavage reaction mixture revealed that the purity of the target product pd2-001 was 93.7 area%, with 2.6 area% of the epimer pd2-001-a and 3.7 area% of the over-elongated product pd2-001-b.

[0373] Analysis conditions: SQDAA50long

[0374] The above results are summarized in the table below.

[0375] Under condition 1, in which a dipeptide was supported, the target product was obtained with high recovery and purity. When a single amino acid was supported, under normal condition 2, not only was a decrease in recovery due to premature cleavage observed, but also the generation of over-elongated products and AA2 deletion products due to poor elongation of AA2, a difficult-to-elongate site. Under condition 3, which corresponds to a difficult-to-elongate sequence, a decrease in recovery due to premature cleavage was observed, and no AA2 deletion products were observed, but an increase in the generation of over-elongated products was observed.

[0376] In addition, under Condition 1, as under Conditions 2 and 3, an epimer (pd2-001-a) was confirmed as an impurity. As mentioned above, this impurity was already present during the preparation of compound aa2-001. In other words, this impurity can be avoided by rigorous purification of compound aa2-001 prepared by the liquid-phase method. On the other hand, under Conditions 2 and 3, which are common peptide synthesis methods, purity decreases due to epimerization on the solid phase. If AA2 is a difficult-to-elongate amino acid that is prone to epimerization during elongation, the superiority of the dipeptide-supported peptide elongation method is also demonstrated in that it can avoid the decrease in peptide purity due to epimerization.

[0377] Synthesis of compound pd2-002-resin, (3S)-3-[[(2S,3S)-2-[[(2S,3S)-2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-methylpentanoyl]-methylamino]-3-methylpentanoyl]-methylamino]-4-oxo-4-piperidin-1-ylbutanoate-2-chlorotrityl resin (Fmoc-Ile-MeIle-MeAsp(O-Trt(2-Cl)resin)-pip)

[0378] Synthesis of pd2-002-resin under Condition 1. Starting from the dipeptide-loaded resin aa2-002-resin (Fmoc-MeIle-MeAsp(O-Trt(2-Cl)resin)-pip) (100 mg, 0.326 mmol / g) prepared in Example 1-4, pd2-002-resin was synthesized by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours) according to Synthesis Method 1. The loading amount was calculated using the dried resin (10.24 mg) by Fmoc quantification to be 0.336 mmol / g (UVarea value at 294 nm: 3446.83, UVarea value at 304 nm: 3102.30).

[0379] The recovery rate was calculated using the following formula according to the recovery rate calculation method: Recovery rate = 0.336 × (1 ÷ 0.326 - 563.70 × 0.001 + 676.86 × 0.001) = 106.9%. Furthermore, when the cleavage reaction solution was analyzed by LCMS, the purity of the target product pd2-002 was 99.4 area%, and 0.6 area% of the epimer pd2-002-a was observed.

[0380] Analysis conditions: SQDAA50long

[0381] Synthesis of pd2-002-resin under Condition 2. Starting from the amino acid-loaded resin aa3-001-resin (Fmoc-MeAsp(O-Trt(2-Cl)resin)-pip) (100 mg, 0.455 mmol / g) prepared in Example 1-4, pd2-002-resin was synthesized by elongation of Fmoc-MeIle-OH (HOAt, 40°C, 2.5 hours), followed by elongation of Fmoc-Ile-OH (HOAt, 40°C, 2.5 hours). The loading amount was calculated using the dried resin (10.81 mg) by Fmoc quantification to be 0.326 mmol / g (UVarea value at 294 nm: 3524.40, UVarea value at 304 nm: 3171.55).

[0382] The recovery rate was calculated using the following formula: Recovery rate = 0.326 × (1 ÷ 0.455 - 436.51 × 0.001 + 676.86 × 0.001) = 79.5%. LCMS analysis of the cleavage reaction mixture revealed that the purity of the target product pd2-002 was 58.0 area%, with the epimer pd2-002-a at 1.4 area%, the over-elongated product pd2-002-b at 1.8 area%, and the AA2 deletion product pd2-002-c at 38.8 area%.

[0383] Analysis conditions: SQDAA50long

[0384] Synthesis of pd2-002-resin under Condition 3. Starting from the amino acid-loaded resin aa3-001-resin (Fmoc-MeAsp(O-Trt(2-Cl)resin)-pip) (100 mg, 0.455 mmol / g) prepared in Example 1-4, pd2-002-resin was synthesized by extending the Fmoc-MeIle-OH moiety (oxyma, 50°C, 10 hours) followed by extending the Fmoc-Ile-OH moiety (HOAt, 40°C, 2.5 hours). The loading amount was calculated using the dried resin (10.41 mg) by Fmoc quantification to be 0.330 mmol / g. (UVarea value at 294 nm: 3437.60, UVarea value at 304 nm: 3100.91).

[0385] The recovery rate was calculated using the following formula according to the recovery rate calculation method: Recovery rate = 0.330 × (1 ÷ 0.455 - 436.51 × 0.001 + 676.86 × 0.001) = 80.5%. LCMS analysis of the cleavage reaction solution revealed that the purity of the target product pd2-002 was 95.2 area%, with 1.4 area% of the epimer pd2-002-a and 3.4 area% of the over-elongated product pd2-002-b.

[0386] Analysis conditions: SQDAA50long

[0387] The above results are summarized in the table below.

[0388] Under condition 1, in which a dipeptide was supported, the target product was obtained with high recovery and purity. When a single amino acid was supported, under normal condition 2, not only was a decrease in recovery due to premature cleavage observed, but also the generation of over-elongated products and AA2 deletion products due to poor elongation of AA2, a difficult-to-elongate site. Under condition 3, which corresponds to a difficult-to-elongate sequence, a decrease in recovery due to premature cleavage was observed, and no AA2 deletion products were observed, but an increase in the generation of over-elongated products was observed.

[0389] Synthesis of compound pd2-003-resin, (3S)-3-[[(2S)-2-cyclopentyl-2-[[(2S,3S)-2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-methylpentanoyl]-methylamino]acetyl]-methylamino]-4-oxo-4-piperidin-1-ylbutanoate-2-chlorotrityl resin (Fmoc-Ile-MeGly(cPent)-MeAsp(O-Trt(2-Cl)resin)-pip)

[0390] Synthesis of pd2-003-resin under Condition 1. Starting from the dipeptide-loaded resin aa2-003-resin (Fmoc-MeGly(cPent)-MeAsp(O-Trt(2-Cl)resin)-pip) (100 mg, 0.362 mmol / g) prepared in Example 1-4, pd2-003-resin was synthesized by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours) according to Synthesis Method 1. The loading amount was calculated using the dried resin (10.14 mg) by Fmoc quantification to be 0.348 mmol / g (UVarea value at 294 nm: 3532.70, UVarea value at 304 nm: 3179.43).

[0391] The recovery rate was calculated using the following formula according to the recovery rate calculation method: Recovery rate = 0.348 × (1 ÷ 0.362 - 575.71 × 0.001 + 688.87 × 0.001) = 100.1%. Furthermore, when the cleavage reaction solution was analyzed by LCMS, the purity of the target product pd2-003 was 99.8 area%, and 0.2 area% of the epimer pd2-003-a was observed.

[0392] Analysis conditions: SQDAA50long

[0393] Synthesis of pd2-003-resin under Condition 2. Starting from the amino acid-loaded resin aa3-001-resin (Fmoc-MeAsp(O-Trt(2-Cl)resin)-pip) (100 mg, 0.455 mmol / g) prepared in Example 1-4, pd2-003-resin was synthesized by following Synthesis Method 1, first elongating the resin to Fmoc-MeGly(cPent)-OH (HOAt, 40°C, 2.5 hours), then elongating the resin to Fmoc-Ile-OH (HOAt, 40°C, 2.5 hours). The loading amount was calculated using the dried resin (10.05 mg) by Fmoc quantification to be 0.320 mmol / g (UVarea value at 294 nm: 3216.77, UVarea value at 304 nm: 2905.18).

[0394] The recovery rate was calculated using the following formula: Recovery rate = 0.320 × (1 ÷ 0.455 - 436.51 × 0.001 + 688.87 × 0.001) = 78.4%. LCMS analysis of the cleavage reaction mixture revealed that the purity of the target product pd2-003 was 83.9 area%, with the epimer pd2-003-a at 1.2 area%, the over-elongated product pd2-003-b at 3.9 area%, and the AA2 deletion product pd2-003-c at 11.0 area%.

[0395] Analysis conditions: SQDAA50long

[0396] Synthesis of pd2-003-resin under Condition 3. Starting from the amino acid-loaded resin aa3-001-resin (Fmoc-MeAsp(O-Trt(2-Cl)resin)-pip) (100 mg, 0.455 mmol / g) prepared in Example 1-4, pd2-003-resin was synthesized by elongation of Fmoc-MeGly(cPent)-OH (oxyma, 50°C, 10 hours), followed by elongation of Fmoc-Ile-OH (HOAt, 40°C, 2.5 hours). The loading amount was calculated using the dried resin (9.45 mg) by Fmoc quantification to be 0.232 mmol / g (UVarea value at 294 nm: 2194.45, UVarea value at 304 nm: 1975.12).

[0397] The recovery rate was calculated using the following formula according to the recovery rate calculation method: Recovery rate = 0.232 × (1 ÷ 0.455 - 436.51 × 0.001 + 688.87 × 0.001) = 56.8%. LCMS analysis of the cleavage reaction solution revealed that the purity of the target product pd2-003 was 91.4 area%, with 0.1 area% of the epimer pd2-003-a and 8.5 area% of the over-elongated product pd2-003-b.

[0398] Analysis conditions: SQDAA50long

[0399] The above results are summarized in the table below.

[0400] Under condition 1, in which a dipeptide was supported, the target product was obtained with high recovery and purity. When a single amino acid was supported, under normal condition 2, not only was a decrease in recovery due to premature cleavage observed, but also the generation of over-elongated products and AA2 deletion products due to poor elongation of AA2, a difficult-to-elongate site. Under condition 3, which corresponds to a difficult-to-elongate sequence, a decrease in recovery due to premature cleavage was observed, and no AA2 deletion products were observed, but an increase in the generation of over-elongated products was observed.

[0401] Synthesis of compound pd2-004-resin, (3S)-3-[[(2S)-2-cyclohexyl-2-[[(2S,3S)-2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-methylpentanoyl]-methylamino]acetyl]-methylamino]-4-oxo-4-piperidin-1-ylbutanoate-2-chlorotrityl resin (Fmoc-Ile-MeChg-MeAsp(O-Trt(2-Cl)resin)-pip)

[0402] Synthesis of pd2-004-resin under Condition 1. Starting from the dipeptide-loaded resin aa2-004-resin (Fmoc-MeChg-MeAsp(O-Trt(2-Cl)resin)-pip) (100 mg, 0.347 mmol / g) prepared in Example 1-4, pd2-004-resin was synthesized by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours) according to Synthesis Method 1. The loading amount was calculated using the dried resin (10.66 mg) by Fmoc quantification to be 0.328 mmol / g (UVarea value at 294 nm: 3502.36, UVarea value at 304 nm: 3152.54).

[0403] The recovery rate was calculated using the following formula according to the recovery rate calculation method: Recovery rate = 0.328 × (1 ÷ 0.347 - 589.73 × 0.001 + 702.89 × 0.001) = 98.2%. Furthermore, when the cleavage reaction solution was analyzed by LCMS, the purity of the target product pd2-004 was 99.2 area%, and 0.8 area% of the epimer pd2-004-a was observed.

[0404] Analysis conditions: SQDAA50long

[0405] Synthesis of pd2-004-resin under Condition 2. Starting from the amino acid-loaded resin aa3-001-resin (Fmoc-MeAsp(O-Trt(2-Cl)resin)-pip) (100 mg, 0.455 mmol / g) prepared in Example 1-4, pd2-004-resin was synthesized by following Synthesis Method 1, elongating the Fmoc-MeChg-OH (HOAt, 40°C, 2.5 hours) and then elongating the Fmoc-Ile-OH (HOAt, 40°C, 2.5 hours). The loading amount was calculated using the dried resin (9.68 mg) by Fmoc quantification to be 0.314 mmol / g (UVarea value at 294 nm: 3037.14, UVarea value at 304 nm: 2743.09).

[0406] The recovery rate was calculated using the following formula: Recovery rate = 0.314 × (1 ÷ 0.455 - 436.51 × 0.001 + 702.89 × 0.001) = 77.4%. LCMS analysis of the cleavage reaction mixture revealed that the purity of the target product pd2-004 was 74.1 area%, with the epimer pd2-004-a at 2.3 area%, the over-elongated product pd2-004-b at 4.0 area%, and the AA2 deletion product pd2-004-c at 19.5 area%.

[0407] Analysis conditions: SQDAA50long

[0408] Synthesis of pd2-004-resin under Condition 3. Starting from the amino acid-loaded resin aa3-001-resin (Fmoc-MeAsp(O-Trt(2-Cl)resin)-pip) (100 mg, 0.455 mmol / g) prepared in Example 1-4, pd2-004-resin was synthesized by extending the Fmoc-MeChg-OH moiety (oxyma, 50°C, 10 hours) followed by extending the Fmoc-Ile-OH moiety (HOAt, 40°C, 2.5 hours). The loading amount was calculated using the dried resin (9.91 mg) by Fmoc quantification to be 0.226 mmol / g (UVarea value at 294 nm: 2235.50, UVarea value at 304 nm: 2016.81).

[0409] The recovery rate was calculated using the following formula according to the recovery rate calculation method: Recovery rate = 0.226 × (1 ÷ 0.455 - 436.51 × 0.001 + 702.89 × 0.001) = 55.7%. LCMS analysis of the cleavage reaction solution revealed that the purity of the target product pd2-004 was 91.7 area%, with 0.6 area% of the epimer pd2-004-a and 7.7 area% of the over-elongated product pd2-004-b.

[0410] Analysis conditions: SQDAA50long

[0411] The above results are summarized in the table below.

[0412] Under condition 1, in which a dipeptide was supported, the target product was obtained with high recovery and purity. When a single amino acid was supported, under normal condition 2, not only was a decrease in recovery due to premature cleavage observed, but also the generation of over-elongated products and AA2 deletion products due to poor elongation of AA2, a difficult-to-elongate site. Under condition 3, which corresponds to a difficult-to-elongate sequence, a decrease in recovery due to premature cleavage was observed, and no AA2 deletion products were observed, but an increase in the generation of over-elongated products was observed.

[0413] Synthesis of compound pd2-005-resin, (3S)-3-[[(2S)-2-[[(2S,3S)-2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-methylpentanoyl]-methylamino]-4-methylpentanoyl]-methylamino]-4-oxo-4-piperidin-1-ylbutanoate-2-chlorotrityl resin (Fmoc-Ile-MeLeu-MeAsp(O-Trt(2-Cl)resin)-pip)

[0414] Synthesis of pd2-005-resin under Condition 1. Starting from the dipeptide-loaded resin aa2-005-resin (Fmoc-MeLeu-MeAsp(O-Trt(2-Cl)resin)-pip) (100 mg, 0.355 mmol / g) prepared in Example 1-4, pd2-005-resin was synthesized by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours) according to Synthesis Method 1. The loading amount was calculated using the dried resin (10.81 mg) by Fmoc quantification to be 0.342 mmol / g (UVarea value at 294 nm: 3697.14, UVarea value at 304 nm: 3330.28).

[0415] The recovery rate was calculated using the following formula according to the recovery rate calculation method: Recovery rate = 0.342 × (1 ÷ 0.355 - 563.70 × 0.001 + 676.86 × 0.001) = 100.2%. Furthermore, when the cleavage reaction solution was analyzed by LCMS, the purity of the target product pd2-005 was 99.9 area%, and 0.1 area% of the epimer pd2-005-a was observed.

[0416] Analysis conditions: SQDAA50long

[0417] Synthesis of pd2-005-resin under Condition 2. Starting from the amino acid-loaded resin aa3-001-resin (Fmoc-MeAsp(O-Trt(2-Cl)resin)-pip) (100 mg, 0.455 mmol / g) prepared in Example 1-4, pd2-005-resin was synthesized by following Synthesis Method 1, elongating the Fmoc-MeLeu-OH (HOAt, 40°C, 2.5 hours) and then elongating the Fmoc-Ile-OH (HOAt, 40°C, 2.5 hours). The loading amount was calculated using the dried resin (10.74 mg) by Fmoc quantification to be 0.369 mmol / g (UVarea value at 294 nm: 3953.19, UVarea value at 304 nm: 3570.96).

[0418] The recovery rate was calculated using the following formula: Recovery rate = 0.369 × (1 ÷ 0.455 - 436.51 × 0.001 + 676.86 × 0.001) = 90.0%. LCMS analysis of the cleavage reaction mixture revealed that the purity of the target product pd2-005 was 98.3 area%, with 0.1 area% of the epimer pd2-005-a and 1.6 area% of the over-extended product pd2-005-b. With this substrate, the AA2 deletion product pd2-005-c was not observed, even under condition 2.

[0419] Analysis conditions: SQDAA50long

[0420] Synthesis of pd2-005-resin under Condition 3. Starting from the amino acid-loaded resin aa3-001-resin (Fmoc-MeAsp(O-Trt(2-Cl)resin)-pip) (100 mg, 0.455 mmol / g) prepared in Example 1-4, pd2-005-resin was synthesized by extending the Fmoc-MeLeu-OH (oxyma, 50°C, 10 hours) and then extending the Fmoc-Ile-OH (HOAt, 40°C, 2.5 hours) according to Synthesis Method 1. The loading amount was calculated using the dried resin (10.73 mg) by Fmoc quantification to be 0.337 mmol / g (UVarea value at 294 nm: 3610.72, UVarea value at 304 nm: 3254.78).

[0421] The recovery rate was calculated using the following formula according to the recovery rate calculation method: Recovery rate = 0.337 × (1 ÷ 0.455 - 436.51 × 0.001 + 676.86 × 0.001) = 82.2%. LCMS analysis of the cleavage reaction solution revealed that the purity of the target product pd2-005 was 97.7 area%, with 0.1 area% of the epimer pd2-005-a and 2.2 area% of the over-elongated product pd2-005-b.

[0422] Analysis conditions: SQDAA50long

[0423] The above results are summarized in the table below. Under condition 1, in which a dipeptide was supported, the target product was obtained with high recovery and purity. Under conditions 2 and 3, in which a single amino acid was supported, not only was recovery reduced due to premature cleavage, but the formation of over-elongated products was also observed.

[0424] Synthesis of compound pd2-006-resin, (3S)-3-[[(2S)-2-cyclopentyl-2-[[(2S,3S)-2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-methylpentanoyl]-methylamino]acetyl]-methylamino]-4-(dimethylamino)-4-oxobutanoate-2-chlorotrityl resin (Fmoc-Ile-MeGly(cPent)-MeAsp(O-Trt(2-Cl)resin)-NMe2).

[0425] Synthesis of pd2-006-resin under Condition 1. Starting from the dipeptide-loaded resin aa2-006-resin (Fmoc-MeGly(cPent)-MeAsp(O-Trt(2-Cl)resin)-NMe2) (100 mg, 0.345 mmol / g) prepared in Example 1-4, pd2-006-resin was synthesized by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours) according to Synthesis Method 1. The loading amount was calculated using the dried resin (10.23 mg) by Fmoc quantification to be 0.349 mmol / g (UVarea value at 294 nm: 3565.79, UVarea value at 304 nm: 3223.59).

[0426] The recovery rate was calculated using the following formula according to the recovery rate calculation method: Recovery rate = 0.349 × (1 ÷ 0.345 - 535.64 × 0.001 + 648.80 × 0.001) = 105.1%. Furthermore, when the cleavage reaction solution was analyzed by LCMS, the purity of the target product pd2-006 was found to be 100 area%.

[0427] Analysis conditions: SQDFA05

[0428] Synthesis of pd2-006-resin under Condition 2. Starting from the amino acid-loaded resin aa3-002-resin (Fmoc-MeAsp(O-Trt(2-Cl)resin)-NMe2) (100 mg, 0.442 mmol / g) prepared in Example 1-4, pd2-006-resin was synthesized by elongation of Fmoc-MeGly(cPent)-OH (HOAt, 40°C, 2.5 hours) followed by elongation of Fmoc-Ile-OH (HOAt, 40°C, 2.5 hours). The loading amount was calculated using the dried resin (10.73 mg) by Fmoc quantification to be 0.304 mmol / g (UVarea value at 294 nm: 3263.10, UVarea value at 304 nm: 2945.28).

[0429] The recovery rate was calculated using the following formula: Recovery rate = 0.304 × (1 ÷ 0.442 - 396.44 × 0.001 + 648.80 × 0.001) = 76.5%. LCMS analysis of the cleavage reaction mixture revealed that the purity of the target product pd2-006 was 76.3 area%, with the epimer pd2-006-a at 1.2 area%, the over-extended product pd2-006-b at 5.6 area%, and the AA2 deletion product pd2-006-c at 16.9 area%.

[0430] Analysis conditions: SQDFA05

[0431] Synthesis of pd2-006-resin under Condition 3. Starting from the amino acid-loaded resin aa3-002-resin (Fmoc-MeAsp(O-Trt(2-Cl)resin)-NMe2) (100 mg, 0.442 mmol / g) prepared in Example 1-4, pd2-006-resin was synthesized by elongation of Fmoc-MeGly(cPent)-OH (oxyma, 50°C, 10 hours), followed by elongation of Fmoc-Ile-OH (HOAt, 40°C, 2.5 hours). The loading amount was calculated using the Fmoc quantification method using dried resin (10.60 mg) to be 0.211 mmol / g (UVarea value at 294 nm: 2239.56, UVarea value at 304 nm: 2018.13).

[0432] The recovery rate was calculated using the following formula: Recovery rate = 0.211 × (1 ÷ 0.442 - 396.44 × 0.001 + 648.80 × 0.001) = 53.1%. LCMS analysis of the cleavage reaction mixture revealed that the purity of the target product pd2-006 was 85.9 area%, and that the over-extended product pd2-006-b was 14.1 area%.

[0433] Analysis conditions: SQDFA05

[0434] The above results are summarized in the table below.

[0435] Under condition 1, in which a dipeptide was supported, the target product was obtained with high recovery and purity. When a single amino acid was supported, under normal condition 2, not only was a decrease in recovery due to premature cleavage observed, but also the generation of over-elongated products and AA2 deletion products due to poor elongation of AA2, a difficult-to-elongate site. Under condition 3, which corresponds to a difficult-to-elongate sequence, a decrease in recovery due to premature cleavage was observed, and no AA2 deletion products were observed, but an increase in the generation of over-elongated products was observed.

[0436] Synthesis of compound pd2-007-resin, (3S)-4-(dimethylamino)-3-[[(2S)-2-[[(2S,3S)-2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-methylpentanoyl]-methylamino]-4-methylpentanoyl]-methylamino]-4-oxobutanoate-2-chlorotrityl resin (Fmoc-Ile-MeLeu-MeAsp(O-Trt(2-Cl)resin)-NMe2).

[0437] Synthesis of pd2-007-resin under Condition 1. Starting from the dipeptide-loaded resin aa2-007-resin (Fmoc-MeLeu-MeAsp(O-Trt(2-Cl)resin)-NMe2) (100 mg, 0.384 mmol / g) prepared in Example 1-4, pd2-007-resin was synthesized by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours) according to Synthesis Method 1. The loading amount was calculated using the dried resin (9.96 mg) by Fmoc quantification to be 0.367 mmol / g (UVarea value at 294 nm: 3654.86, UVarea value at 304 nm: 3298.78).

[0438] The recovery rate was calculated using the following formula according to the recovery rate calculation method: Recovery rate = 0.367 × (1 ÷ 0.384 - 523.63 × 0.001 + 636.79 × 0.001) = 99.7%. Furthermore, when the cleavage reaction solution was analyzed by LCMS, the purity of the target product pd2-007 was found to be 100 area%.

[0439] Analysis conditions: SQDFA05

[0440] Synthesis of pd2-007-resin under Condition 2. Starting from the amino acid-loaded resin aa3-002-resin (Fmoc-MeAsp(O-Trt(2-Cl)resin)-NMe2) (100 mg, 0.442 mmol / g) prepared in Example 1-4, pd2-007-resin was synthesized by following Synthesis Method 1, elongating the Fmoc-MeLeu-OH (HOAt, 40°C, 2.5 hours) and then elongating the Fmoc-Ile-OH (HOAt, 40°C, 2.5 hours). The loading amount was calculated using the dried resin (10.15 mg) by Fmoc quantification to be 0.371 mmol / g (UVarea value at 294 nm: 3770.57, UVarea value at 304 nm: 3391.62).

[0441] The recovery rate was calculated using the following formula: Recovery rate = 0.371 × (1 ÷ 0.442 - 396.44 × 0.001 + 636.79 × 0.001) = 92.9%. When the cleavage reaction solution was analyzed by LCMS, the purity of the target product pd2-007 was 97.9 area%, and the over-extended product pd2-007-b was observed at 2.1 area%. With this substrate, the AA2 deletion product pd2-007-c was not observed, even under condition 2.

[0442] Analysis conditions: SQDFA05

[0443] Synthesis of pd2-007-resin under Condition 3. Starting from the amino acid-loaded resin aa3-002-resin (Fmoc-MeAsp(O-Trt(2-Cl)resin)-NMe2) (100 mg, 0.442 mmol / g) prepared in Example 1-4, pd2-007-resin was synthesized by extending the Fmoc-MeLeu-OH (oxyma, 50°C, 10 hours) and then extending the Fmoc-Ile-OH (HOAt, 40°C, 2.5 hours) according to Synthesis Method 1. The loading amount was calculated using the dried resin (10.73 mg) by Fmoc quantification to be 0.334 mmol / g (UVarea value at 294 nm: 3587.19, UVarea value at 304 nm: 3234.07).

[0444] The recovery rate was calculated using the following formula: Recovery rate = 0.334 × (1 ÷ 0.442 - 396.44 × 0.001 + 636.79 × 0.001) = 83.6%. LCMS analysis of the cleavage reaction mixture revealed that the purity of the target product pd2-007 was 96.6 area%, and that the over-extended product pd2-007-b was 3.4 area%.

[0445] Analysis conditions: SQDFA05

[0446] The above results are summarized in the table below.

[0447] Under condition 1, in which a dipeptide was supported, the target product was obtained with high recovery and purity. Under conditions 2 and 3, in which a single amino acid was supported, not only was recovery reduced due to premature cleavage, but the formation of over-elongated products was also observed.

[0448] Synthesis of compound pd2-008-resin, (3R)-3-[[(2S)-2-[[(2S,3S)-2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-methylpentanoyl]-methylamino]-3-methylbutanoyl]-methylamino]butanoate-2-chlorotrityl resin (Fmoc-Ile-MeVal-D-3-MeAbu-O-Trt(2-Cl)resin)

[0449] Synthesis of pd2-008-resin under Condition 1. Starting from the dipeptide-loaded resin aa2-008-resin (Fmoc-MeVal-D-3-MeAbu-O-Trt(2-Cl)resin) (100 mg, 0.415 mmol / g) prepared in Example 1-4, pd2-008-resin was synthesized by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours) according to Synthesis Method 1. The loading amount was calculated using the dried resin (10.74 mg) by Fmoc quantification to be 0.378 mmol / g (UVarea value at 294 nm: 4060.03, UVarea value at 304 nm: 3652.89).

[0450] The recovery rate was calculated using the following formula according to the recovery rate calculation method: Recovery rate = 0.378 × (1 ÷ 0.415 - 452.44 × 0.001 + 565.71 × 0.001) = 95.4%. Furthermore, when the cleavage reaction solution was analyzed by LCMS, the purity of the target product pd2-008 was found to be 100 area%.

[0451] Analysis conditions: SQDAA50long

[0452] Synthesis of pd2-008-resin under Condition 2. Starting from the amino acid-loaded resin aa4-001-resin (Fmoc-D-3-MeAbu-O-Trt(2-Cl) resin) (100 mg, 0.369 mmol / g) prepared in Example 1-4, pd2-008-resin was synthesized by extending the Fmoc-MeVal-OH moiety (HOAt, 40°C, 2.5 hours) followed by extending the Fmoc-Ile-OH moiety (HOAt, 40°C, 2.5 hours). The loading amount was calculated using the dried resin (10.62 mg) by Fmoc quantification to be 0.295 mmol / g (UVarea value at 294 nm: 3138.26, UVarea value at 304 nm: 2821.05).

[0453] The recovery rate was calculated using the following formula: Recovery rate = 0.295 × (1 ÷ 0.369 - 339.39 × 0.001 + 565.71 × 0.001) = 86.6%. LCMS analysis of the cleavage reaction mixture revealed that the purity of the target product, pd2-008, was 99.1 area%, with 1.0 area% of the overextended product, pd2-008-b. With this substrate, the AA2 deletion product, pd2-008-c, was not observed, even under condition 2.

[0454] Analysis conditions: SQDAA50long

[0455] Synthesis of pd2-008-resin under Condition 3. Starting from the amino acid-loaded resin aa4-001-resin (Fmoc-D-3-MeAbu-O-Trt(2-Cl) resin) (100 mg, 0.369 mmol / g) prepared in Example 1-4, pd2-008-resin was synthesized by extending the Fmoc-MeVal-OH moiety (oxyma, 50°C, 10 hours) and then extending the Fmoc-Ile-OH moiety (HOAt, 40°C, 2.5 hours) according to Synthesis Method 1. The loading amount was calculated using the dried resin (10.44 mg) by Fmoc quantification to be 0.284 mmol / g (UVarea value at 294 nm: 2964.86, UVarea value at 304 nm: 2667.78).

[0456] The recovery rate was calculated using the following formula: Recovery rate = 0.284 × (1 ÷ 0.369 - 339.39 × 0.001 + 565.71 × 0.001) = 83.4%. LCMS analysis of the cleavage reaction solution revealed that the purity of the target product pd2-008 was 98.1 area%, and that the over-extended product pd2-008-b was 1.9 area%.

[0457] Analysis conditions: SQDAA50long

[0458] The above results are summarized in the table below.

[0459] Under condition 1, in which a dipeptide was supported, the target product was obtained with high recovery and purity. Under conditions 2 and 3, in which a single amino acid was supported, not only was recovery reduced due to premature cleavage, but the formation of over-elongated products was also observed.

[0460] Synthesis of compound pd2-009-resin, (3R)-3-[[(2S)-2-cyclohexyl-2-[[(2S,3S)-2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-methylpentanoyl]-methylamino]acetyl]-methylamino]butanoate-2-chlorotrityl resin (Fmoc-Ile-MeChg-D-3-MeAbu-O-Trt(2-Cl)resin)

[0461] Synthesis of pd2-009-resin under Condition 1. Starting from the dipeptide-loaded resin aa2-009-resin (Fmoc-MeChg-D-3-MeAbu-O-Trt(2-Cl)resin) (100 mg, 0.397 mmol / g) prepared in Example 1-4, pd2-009-resin was synthesized by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours) according to Synthesis Method 1. The loading amount was calculated using the dried resin (11.10 mg) by Fmoc quantification to be 0.362 mmol / g (UVarea value at 294 nm: 4014.43, UVarea value at 304 nm: 3627.15).

[0462] The recovery rate was calculated using the following formula according to the recovery rate calculation method: Recovery rate = 0.362 × (1 ÷ 0.397 - 492.62 × 0.001 + 605.78 × 0.001) = 95.3%. Furthermore, when the cleavage reaction solution was analyzed by LCMS, the purity of the target product pd2-009 was found to be 100 area%.

[0463] Analysis conditions: SQDFA05long It should be noted that the retention time of pd2-009 in this experiment (condition 1) does not completely match the retention time of pd2-009 under condition 3, but this is due to inter-measurement error.

[0464] Synthesis of pd2-009-resin under Condition 2. Starting from the amino acid-loaded resin aa4-001-resin (Fmoc-D-3-MeAbu-O-Trt(2-Cl) resin) (100 mg, 0.369 mmol / g) prepared in Example 1-4, pd2-009-resin was synthesized by extending the Fmoc-MeChg-OH (HOAt, 40°C, 2.5 hours) and then extending the Fmoc-Ile-OH (HOAt, 40°C, 2.5 hours) according to Synthesis Method 1. The loading amount was calculated using the dried resin (10.20 mg) by Fmoc quantification to be 0.293 mmol / g (UVarea value at 294 nm: 2987.04, UVarea value at 304 nm: 2692.68).

[0465] The recovery rate was calculated using the following formula: Recovery rate = 0.293 × (1 ÷ 0.369 - 339.39 × 0.001 + 605.78 × 0.001) = 87.2%. LCMS analysis of the excision reaction solution revealed that the purity of the target product, pd2-009, was 92.8 area%, with the overextended form pd2-009-b at 3.4 area% and the AA2 deletion form pd2-009-c at 3.8 area%.

[0466] Analysis conditions: SQDFA05long It should be noted that the retention times of pd2-009 and pd2-009-b in this experiment (condition 2) do not completely match the retention times of pd2-009 and pd2-009-b in condition 3, but this is due to inter-measurement error.

[0467] Synthesis of pd2-009-resin under Condition 3. Starting from the amino acid-loaded resin aa4-001-resin (Fmoc-D-3-MeAbu-O-Trt(2-Cl) resin) (100 mg, 0.369 mmol / g) prepared in Example 1-4, pd2-009-resin was synthesized by extending the Fmoc-MeChg-OH moiety (oxyma, 50°C, 10 hours) followed by extending the Fmoc-Ile-OH moiety (HOAt, 40°C, 2.5 hours). The loading amount was calculated using the dried resin (9.56 mg) by Fmoc quantification to be 0.217 mmol / g (UVarea value at 294 nm: 2072.81, UVarea value at 304 nm: 1864.82).

[0468] The recovery rate was calculated using the following formula: Recovery rate = 0.217 × (1 ÷ 0.369 - 339.39 × 0.001 + 605.78 × 0.001) = 64.6%. LCMS analysis of the cleavage reaction solution revealed that the purity of the target product pd2-009 was 94.5 area%, and that the over-extended product pd2-009-b was 5.5 area%.

[0469] Analysis conditions: SQDFA05long

[0470] The above results are summarized in the table below.

[0471] Under condition 1, in which a dipeptide was supported, the target product was obtained with high recovery and purity. When a single amino acid was supported, under normal condition 2, not only was a decrease in recovery due to premature cleavage observed, but also the generation of over-elongated products and AA2 deletion products due to poor elongation of AA2, a difficult-to-elongate site. Under condition 3, which corresponds to a difficult-to-elongate sequence, a decrease in recovery due to premature cleavage was observed, and no AA2 deletion products were observed, but an increase in the generation of over-elongated products was observed.

[0472] Synthesis of compound pd2-010-resin, 2-[[(2S)-2-[[(2S,3S)-2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-methylpentanoyl]-methylamino]-3-methylbutanoyl]-methylamino]acetic acid-2-chlorotrityl resin (Fmoc-Ile-MeVal-MeGly-O-Trt(2-Cl)resin)

[0473] Synthesis of pd2-010-resin under Condition 1. Starting from the dipeptide-loaded resin aa2-010-resin (Fmoc-MeVal-MeGly-O-Trt(2-Cl)resin) (100 mg, 0.374 mmol / g) prepared in Example 1-4, pd2-010-resin was synthesized by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours) according to Synthesis Method 1. The loading amount was calculated using the dried resin (10.86 mg) by Fmoc quantification to be 0.325 mmol / g (UVarea value at 294 nm: 3525.31, UVarea value at 304 nm: 3180.92).

[0474] The recovery rate was calculated using the following formula according to the recovery rate calculation method: Recovery rate = 0.325 × (1 ÷ 0.374 - 424.50 × 0.001 + 537.66 × 0.001) = 90.6%. Furthermore, when the cleavage reaction solution was analyzed by LCMS, the purity of the target product pd2-010 was found to be 100 area%.

[0475] Analysis conditions: SQDFA05

[0476] Synthesis of pd2-010-resin under Condition 2. Starting from the amino acid-loaded resin aa4-002-resin (Fmoc-MeGly-O-Trt(2-Cl) resin) (100 mg, 0.573 mmol / g) prepared in Example 1-4, pd2-010-resin was synthesized by following Synthesis Method 1, elongating the Fmoc-MeVal-OH (HOAt, 40°C, 2.5 hours) and then elongating the Fmoc-Ile-OH (HOAt, 40°C, 2.5 hours). The loading amount was calculated using the dried resin (10.20 mg) by Fmoc quantification to be 0.326 mmol / g (UVarea value at 294 nm: 3322.12, UVarea value at 304 nm: 3002.34).

[0477] The recovery rate was calculated using the following formula: Recovery rate = 0.326 × (1 ÷ 0.573 - 311.34 × 0.001 + 537.66 × 0.001) = 64.3%. LCMS analysis of the cleavage reaction mixture revealed that the purity of the target product, pd2-010, was 95.6 area%, with the overextended product pd2-010-b at 4.4 area%. With this substrate, the AA2 deletion product, pd2-010-c, was not observed, even under condition 2.

[0478] Analysis conditions: SQDFA05

[0479] Synthesis of pd2-010-resin under Condition 3. Starting from the amino acid-loaded resin aa4-002-resin (Fmoc-MeGly-(O-Trt(2-Cl)resin)) (100 mg, 0.573 mmol / g) prepared in Example 1-4, pd2-010-resin was synthesized by extending the Fmoc-MeVal-OH moiety (oxyma, 50°C, 10 hours) and then extending the Fmoc-Ile-OH moiety (HOAt, 40°C, 2.5 hours) according to Synthesis Method 1. The loading amount was calculated using the dried resin (10.69 mg) by Fmoc quantification to be 0.331 mmol / g (UVarea value at 294 nm: 3542.66, UVarea value at 304 nm: 3189.92).

[0480] The recovery rate was calculated using the following formula: Recovery rate = 0.331 × (1 ÷ 0.573 - 311.34 × 0.001 + 537.66 × 0.001) = 65.3%. LCMS analysis of the cleavage reaction mixture revealed that the purity of the target product pd2-010 was 93.9 area%, and that the over-elongated product pd2-010-b was 6.1 area%.

[0481] Analysis conditions: SQDFA05

[0482] The above results are summarized in the table below.

[0483] Under condition 1, in which a dipeptide was supported, the target product was obtained with high recovery and purity. Under conditions 2 and 3, in which a single amino acid was supported, not only was recovery reduced due to premature cleavage, but the formation of over-elongated products was also observed.

[0484] Synthesis of compound pd2-011-resin, (3S)-4-(dimethylamino)-3-[[(2S)-2-[[(2S,3S)-2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-methylpentanoyl]-methylamino]-3-methylbutanoyl]amino]-4-oxobutanoate-2-chlorotrityl resin (Fmoc-Ile-MeVal-Asp(O-Trt(2-Cl)resin)-NMe2).

[0485] Synthesis of pd2-011-resin under Condition 1. Using the dipeptide-loaded resin aa2-012-resin (Fmoc-MeVal-Asp(O-Trt(2-Cl)resin)-NMe2) (100 mg, 0.373 mmol / g) prepared in Example 1-4 as starting material, pd2-011-resin was synthesized by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours) according to Synthesis Method 1. The loading amount was calculated using the dried resin (9.87 mg) by Fmoc quantification to be 0.343 mmol / g (UVarea value at 294 nm: 3397.67, UVarea value at 304 nm: 3086.76). The recovery rate was calculated using the following formula according to the recovery rate calculation method. Recovery rate = 0.343 × (1 ÷ 0.373 - 495.57 × 0.001 + 608.73 × 0.001) = 95.8%. Furthermore, when the cleavage reaction solution was analyzed by LCMS, the purity of the target product pd2-011 was found to be 100 area%.

[0486] Analysis conditions: SQDFA05long

[0487] Synthesis of pd2-011-resin under Condition 2. Using the amino acid-loaded resin aa3-003-resin (Fmoc-Asp(O-Trt(2-Cl)resin)-NMe2) (100 mg, 0.469 mmol / g) prepared in Example 1-4 as starting material, pd2-011-resin was synthesized by carrying out Fmoc-MeVal-OH extension (HOAt, 40°C, 2.5 hours) followed by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours). The loading amount was calculated using the Fmoc quantitation method with dried resin (10.54 mg) to be 0.292 mmol / g (UVarea value at 294 nm: 3084.36, UVarea value at 304 nm: 2800.28). The recovery rate was calculated using the following formula: Recovery rate = 0.292 × (1 ÷ 0.469 - 382.41 × 0.001 + 608.73 × 0.001) = 68.9%. Furthermore, when the cleavage reaction solution was analyzed by LCMS, the purity of the target product pd2-011 was found to be 100 area%.

[0488] Analysis conditions: SQDFA05long

[0489] Synthesis of pd2-011-resin under Condition 3. Using the amino acid-loaded resin aa3-003-resin (Fmoc-Asp(O-Trt(2-Cl)resin)-NMe2) (100 mg, 0.469 mmol / g) prepared in Example 1-4 as starting material, pd2-011-resin was synthesized by elongation of Fmoc-MeVal-OH (oxyma, 50°C, 10 hours), followed by elongation of Fmoc-Ile-OH (HOAt, 40°C, 2.5 hours) according to Synthesis Method 1. The loading amount was calculated using the Fmoc quantification method using 10.13 mg of dried resin, yielding 0.320 mmol / g (UVarea value at 294 nm: 3260.97, UVarea value at 304 nm: 2943.08). The recovery rate was calculated using the following formula: Recovery rate = 0.320 × (1 ÷ 0.469 - 382.41 × 0.001 + 608.73 × 0.001) = 75.5%. Furthermore, when the cleavage reaction solution was analyzed by LCMS, the purity of the target product pd2-011 was found to be 100 area%.

[0490] Analysis conditions: SQDFA05long

[0491] The above results are summarized in the table below.

[0492] Under condition 1, in which a dipeptide was supported, the target product was obtained with high recovery and purity. Under conditions 2 and 3, in which a single amino acid was supported, the target product was obtained with high purity, but a decrease in recovery rate due to premature cleavage was observed.

[0493] Synthesis of compound pd2-012-resin, (3S)-4-(dimethylamino)-3-[[2-[[(2S,3S)-2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-methylpentanoyl]amino]acetyl]-methylamino]-4-oxobutanoate-2-chlorotrityl resin (Fmoc-Ile-Gly-MeAsp(O-Trt(2-Cl)resin)-NMe2)

[0494] Synthesis of pd2-012-resin under Condition 1. Using the dipeptide-loaded resin aa2-013-resin (Fmoc-Gly-MeAsp(O-Trt(2-Cl)resin)-NMe2) (100 mg, 0.386 mmol / g) prepared in Example 1-4 as starting material, pd2-012-resin was synthesized by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours) according to Synthesis Method 1. The loading amount was calculated using the dried resin (12.05 mg) by Fmoc quantitation to be 0.364 mmol / g (UVarea value at 294 nm: 4412.01, UVarea value at 304 nm: 3987.67). The recovery rate was calculated using the following formula according to the recovery rate calculation method. Recovery rate = 0.364 × (1 ÷ 0.386 - 453.49 × 0.001 + 566.65 × 0.001) = 98.4%. Furthermore, when the cleavage reaction solution was analyzed by LCMS, the purity of the target product pd2-012 was found to be 100 area%.

[0495] Analysis conditions: SQDFA05long

[0496] Synthesis of pd2-012-resin under Condition 2. Using the amino acid-loaded resin aa3-002-resin (Fmoc-MeAsp(O-Trt(2-Cl)resin)-NMe2) (100 mg, 0.442 mmol / g) prepared in Example 1-4 as starting material, pd2-012-resin was synthesized by carrying out the following synthesis procedure: Fmoc-Gly-OH extension (HOAt, 40°C, 2.5 hours), followed by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours). The loading amount was calculated using the Fmoc quantitation method with 10.16 mg of dried resin, yielding 0.375 mmol / g (UVarea value at 294 nm: 3841.95, UVarea value at 304 nm: 3448.96). The recovery rate was calculated using the following formula: Recovery rate = 0.375 × (1 ÷ 0.442 - 396.44 × 0.001 + 566.65 × 0.001) = 91.2%. Furthermore, when the cleavage reaction solution was analyzed by LCMS, the purity of the target product pd2-012 was found to be 100 area%.

[0497] Analysis conditions: SQDFA05long

[0498] Synthesis of pd2-012-resin under Condition 3. Using the amino acid-loaded resin aa3-002-resin (Fmoc-MeAsp(O-Trt(2-Cl)resin)-NMe2) (100 mg, 0.442 mmol / g) prepared in Example 1-4 as starting material, pd2-012-resin was synthesized by carrying out Fmoc-Gly-OH extension (oxyma, 50°C, 10 hours) followed by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours). The loading amount was calculated using the Fmoc quantification method using 10.23 mg of dried resin, yielding 0.346 mmol / g (UVarea value at 294 nm: 3565.67, UVarea value at 304 nm: 3211.93). The recovery rate was calculated using the following formula: Recovery rate = 0.346 × (1 ÷ 0.442 - 396.44 × 0.001 + 566.65 × 0.001) = 84.2%. Furthermore, when the cleavage reaction solution was analyzed by LCMS, the purity of the target product pd2-011 was found to be 100 area%.

[0499] Analysis conditions: SQDFA05long

[0500] The above results are summarized in the table below.

[0501] Under condition 1, in which a dipeptide was supported, the target product was obtained with high recovery and purity. Under conditions 2 and 3, in which a single amino acid was supported, the target product was obtained with high purity, but a decrease in recovery rate due to premature cleavage was observed.

[0502] Synthesis of compound pd2-013-resin, (3S)-4-(dimethylamino)-3-[[2-[[(2S,3S)-2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-methylpentanoyl]amino]-2-methylpropanoyl]-methylamino]-4-oxobutanoate-2-chlorotrityl resin (Fmoc-Ile-Aib-MeAsp(O-Trt(2-Cl)resin)-NMe2).

[0503] Synthesis of pd2-013-resin under Condition 1. Using the dipeptide-loaded resin aa2-014-resin (Fmoc-Aib-MeAsp(O-Trt(2-Cl)resin)-NMe2) (100 mg, 0.413 mmol / g) prepared in Example 1-4 as starting material, pd2-013-resin was synthesized by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours) according to Synthesis Method 1. The loading amount was calculated using the dried resin (10.37 mg) by Fmoc quantitation to be 0.305 mmol / g (UVarea value at 294 nm: 3188.07, UVarea value at 304 nm: 2860.10). The recovery rate was calculated using the following formula according to the recovery rate calculation method. Recovery rate = 0.305 × (1 ÷ 0.413 - 481.54 × 0.001 + 594.7 × 0.001) = 77.3%. Furthermore, when the cleavage reaction solution was analyzed by LCMS, the purity of the target product pd2-013 was found to be 100 area%.

[0504] Analysis conditions: SQDFA05long

[0505] Synthesis of pd2-013-resin under Condition 2. Using the amino acid-loaded resin aa3-002-resin (Fmoc-MeAsp(O-Trt(2-Cl)resin)-NMe2) (100 mg, 0.442 mmol / g) prepared in Example 1-4 as starting material, pd2-013-resin was synthesized by elongation of Fmoc-Aib-OH (HOAt, 40°C, 2.5 hours) followed by elongation of Fmoc-Ile-OH (HOAt, 40°C, 2.5 hours). The loading amount was calculated using the Fmoc quantitation method with dried resin (10.66 mg) to be 0.360 mmol / g (UVarea value at 294 nm: 3850.25, UVarea value at 304 nm: 3502.10). The recovery rate was calculated using the following formula: Recovery rate = 0.360 × (1 ÷ 0.442 - 396.44 × 0.001 + 594.7 × 0.001) = 88.6%. LCMS analysis of the cleavage reaction mixture revealed that the purity of the target product, pd2-013, was 2.6 area%, with the AA2 deletion product, pd2-013-c, being the major product at 93.0 area%. No over-extension product, pd2-013-b, was observed, but a by-product, pd3-013-d, was observed at 4.5 area%.

[0506] Analysis conditions: SQDFA05long

[0507] Synthesis of pd2-013-resin under Condition 3. Using the amino acid-loaded resin aa3-002-resin (Fmoc-MeAsp(O-Trt(2-Cl)resin)-NMe2) (100 mg, 0.442 mmol / g) prepared in Example 1-4 as starting material, pd2-013-resin was synthesized by elongation of Fmoc-Aib-OH (oxyma, 50°C, 10 hours), followed by elongation of Fmoc-Ile-OH (HOAt, 40°C, 2.5 hours). The loading amount was calculated using the Fmoc quantitation method with dried resin (10.33 mg) to be 0.195 mmol / g (UVarea value at 294 nm: 2012.66, UVarea value at 304 nm: 1833.56). The recovery rate was calculated using the following formula: Recovery rate = 0.195 × (1 ÷ 0.442 - 396.44 × 0.001 + 594.7 × 0.001) = 48.0%. LCMS analysis of the cleavage reaction mixture revealed that the purity of the target product, pd2-013, was 21.6 area%, with the overextended product pd2-013-b at 27.3 area% and the AA2 deletion product pd2-013-c at 36.5 area%. Other by-products observed were pd3-013-d at 6.9 area%, pd3-013-e at 5.6 area%, and pd3-013-f at 2.1 area%.

[0508] Analysis conditions: SQDFA05long

[0509] The above results are summarized in the table below.

[0510] Under condition 1, in which a dipeptide was supported, the target product was obtained with high recovery and purity. Under conditions 2 and 3, in which a single amino acid was supported, the yield of the Aib elongation reaction was poor, and over-elongated products and AA2 deletion products were obtained as the main products.

[0511] Synthesis of compound pd2-014-resin, (3R)-3-[[3-[[(2S,3S)-2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-methylpentanoyl]amino]-2,2-dimethylpropanoyl]-methylamino]butanoate-2-chlorotrityl resin (Fmoc-Ile-bAla(2-Me2)-D-3-MeAbu-O-Trt(2-Cl)resin)

[0512] Synthesis of pd2-014-resin under Condition 1. Using the dipeptide-loaded resin aa2-015-resin (Fmoc-bAla(2-Me2)-D-3-MeAbu-O-Trt(2-Cl) resin) (100 mg, 0.443 mmol / g) prepared in Example 1-4 as starting material, pd2-014-resin was synthesized by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours) according to Synthesis Method 1. The loading amount was calculated using the dried resin (11.21 mg) by Fmoc quantification to be 0.397 mmol / g (UVarea value at 294 nm: 4470.95, UVarea value at 304 nm: 4038.87). The recovery rate was calculated using the following formula according to the recovery rate calculation method. Recovery rate = 0.397 × (1 ÷ 0.443 - 438.52 × 0.001 + 551.67 × 0.001) = 94.1%. Furthermore, when the cleavage reaction solution was analyzed by LCMS, the purity of the target product pd2-014 was found to be 100 area%.

[0513] Analysis conditions: SQDAA50long

[0514] Synthesis of pd2-014-resin under Condition 2. Starting from the amino acid-loaded resin aa4-001-resin (Fmoc-D-3-MeAbu-O-Trt(2-Cl)resin) (100 mg, 0.369 mmol / g) prepared in Example 1-4, pd2-014-resin was synthesized by elongation of Fmoc-bAla(2-Me2)-OH (HOAt, 40°C, 2.5 hours) followed by elongation of Fmoc-Ile-OH (HOAt, 40°C, 2.5 hours) according to Synthesis Method 1. The loading amount was calculated to be 0.239 mmol / g using the dried resin (9.9 mg) by Fmoc quantitation. (UVarea value at 294 nm: 2380.93, UVarea value at 304 nm: 2140.88) The recovery rate was calculated using the following formula: Recovery rate = 0.239 × (1 ÷ 0.369 - 339.38 × 0.001 + 551.67 × 0.001) = 69.8%. LCMS analysis of the cleavage reaction mixture revealed that the purity of the target product pd2-014 was 68.1 area%, with the overextended product pd2-014-b at 4.8 area%, the AA2 deletion product pd2-014-c at 22.8 area%, and the by-product pd3-014-d at 4.3 area%.

[0515] Analysis conditions: SQDAA50long

[0516] Synthesis of pd2-014-resin under Condition 3. Using the amino acid-loaded resin aa4-001-resin (Fmoc-D-3-MeAbu-O-Trt(2-Cl)resin) (100 mg, 0.369 mmol / g) prepared in Example 1-4 as starting material, pd2-014-resin was synthesized by elongation of Fmoc-bAla(2-Me2)-OH (oxyma, 50°C, 10 hours), followed by elongation of Fmoc-Ile-OH (HOAt, 40°C, 2.5 hours) according to Synthesis Method 1. The loading amount was calculated to be 0.227 mmol / g using the dried resin (10.86 mg) by Fmoc quantitation. (UVarea value at 294 nm: 2472.50, UVarea value at 304 nm: 2237.05) The recovery rate was calculated using the following formula: Recovery rate = 0.227 × (1 ÷ 0.369 - 339.38 × 0.001 + 551.67 × 0.001) = 66.3%. LCMS analysis of the cleavage reaction mixture revealed that the purity of the target product pd2-014 was 73.9 area%, with the over-extended product pd2-014-b at 22.4 area% and the by-product pd3-014-d at 3.7 area%.

[0517] Analysis conditions: SQDAA50long

[0518] The above results are summarized in the table below.

[0519] Under condition 1, in which a dipeptide was supported, the target product was obtained with high recovery and purity. When a single amino acid was supported, under normal condition 2, not only was a decrease in recovery due to premature cleavage observed, but also the generation of over-elongated products and AA2 deletion products due to poor elongation of AA2, a difficult-to-elongate site. Under condition 3, which corresponds to a difficult-to-elongate sequence, a decrease in recovery due to premature cleavage was observed, and no AA2 deletion products were observed, but an increase in the generation of over-elongated products was observed.

[0520] Synthesis of compound pd2-015-resin, (2S)-2-[[(2S)-2-[[(2S,3S)-2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-methylpentanoyl]-methylamino]-4-methylpentanoyl]-methylamino]-3-methylbutanoate-2-chlorotrityl resin (Fmoc-Ile-MeLeu-MeVal-O-Trt(2-Cl) resin)

[0521] Synthesis of pd2-015-resin under Condition 1. Using the dipeptide-loaded resin aa2-016-resin (Fmoc-MeLeu-MeVal-O-Trt(2-Cl) resin) (100 mg, 0.348 mmol / g) prepared in Example 1-4 as starting material, pd2-015-resin was synthesized by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours) according to Synthesis Method 1. The loading amount was calculated using the dried resin (10.89 mg) by Fmoc quantification to be 0.336 mmol / g (UVarea value at 294 nm: 3689.12, UVarea value at 304 nm: 3325.56). The recovery rate was calculated according to the following formula: Recovery rate = 0.336 × (1 ÷ 0.348 - 480.6 × 0.001 + 593.75 × 0.001) = 100.4%. Furthermore, when the cleavage reaction solution was analyzed by LCMS, the purity of the target product pd2-015 was found to be 100 area%.

[0522] Analysis conditions: SQDFA05long

[0523] Synthesis of pd2-015-resin under Condition 2. Using the amino acid-loaded resin aa4-003-resin (Fmoc-MeVal-O-Trt(2-Cl) resin) (100 mg, 0.436 mmol / g) prepared in Example 1-4 as starting material, pd2-015-resin was synthesized by carrying out Fmoc-MeLeu-OH extension (HOAt, 40°C, 2.5 hours) followed by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours). The loading amount was calculated using the Fmoc quantitation method using 10.26 mg of dried resin, yielding 0.196 mmol / g (UVarea value at 294 nm: 2024.53, UVarea value at 304 nm: 1825.85). The recovery rate was calculated using the following formula: Recovery rate = 0.196 × (1 ÷ 0.436 - 353.41 × 0.001 + 593.75 × 0.001) = 49.7%. Furthermore, when the cleavage reaction solution was analyzed by LCMS, the purity of the target product pd2-015 was 94.5 area%, and the AA2-deleted form pd2-015-c was observed at 5.5 area%.

[0524] Analysis conditions: SQDFA05long

[0525] Synthesis of pd2-015-resin under Condition 3. Using the amino acid-loaded resin aa4-003-resin (Fmoc-MeVal-O-Trt(2-Cl) resin) (100 mg, 0.436 mmol / g) prepared in Example 1-4 as starting material, pd2-015-resin was synthesized by carrying out Fmoc-MeLeu-OH extension (oxyma, 50°C, 10 hours) followed by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours). The loading amount was calculated using the Fmoc quantification method using 11.7 mg of dried resin, yielding 0.172 mmol / g (UVarea value at 294 nm: 2031.91, UVarea value at 304 nm: 1827.32). The recovery rate was calculated using the following formula: Recovery rate = 0.172 × (1 ÷ 0.436 - 353.41 × 0.001 + 593.75 × 0.001) = 43.6%. Furthermore, when the cleavage reaction solution was analyzed by LCMS, the purity of the target product pd2-015 was found to be 100 area%.

[0526] Analysis conditions: SQDFA05long

[0527] The above results are summarized in the table below.

[0528] Under condition 1, in which a dipeptide was supported, the target product was obtained with high recovery and purity. When a single amino acid was supported, under normal condition 2, not only was the recovery rate reduced due to premature cleavage, but also the formation of AA2 deletion mutants due to poor elongation of AA2, a difficult-to-elongate site, was observed. Under condition 3, which corresponds to a difficult-to-elongate sequence, the target product was obtained with high purity, but a reduction in recovery due to premature cleavage was observed.

[0529] Synthesis of compound pd2-016-resin, (2S)-1-[(2S)-2-[[(2S,3S)-2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-methylpentanoyl]-methylamino]-3-methylbutanoyl]pyrrolidine-2-carboxylate-2-chlorotrityl resin (Fmoc-Ile-MeVal-Pro-O-Trt(2-Cl)resin)

[0530] Synthesis of pd2-016-resin under Condition 1. Using the dipeptide-loaded resin aa2-017-resin (Fmoc-MeVal-Pro-O-Trt(2-Cl) resin) (100 mg, 0.364 mmol / g) prepared in Example 1-4 as starting material, pd2-016-resin was synthesized by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours) according to Synthesis Method 1. The loading amount was calculated using the dried resin (10.32 mg) by Fmoc quantification to be 0.344 mmol / g (UVarea value at 294 nm: 3574.16, UVarea value at 304 nm: 3214.28). The recovery rate was calculated using the following formula according to the recovery rate calculation method. Recovery rate = 0.344 × (1 ÷ 0.364 - 450.53 × 0.001 + 563.68 × 0.001) = 98.4%. Furthermore, when the cleavage reaction solution was analyzed by LCMS, the purity of the target product pd2-016 was found to be 100 area%.

[0531] Analysis conditions: SQDFA05long

[0532] Synthesis of pd2-016-resin under Condition 2. Using the amino acid-loaded resin aa4-004-resin (Fmoc-Pro-O-Trt(2-Cl) resin) (100 mg, 0.432 mmol / g) prepared in Example 1-4 as starting material, pd2-016-resin was synthesized by carrying out Fmoc-MeVal-OH extension (HOAt, 40°C, 2.5 hours) followed by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours). The loading amount was calculated using the Fmoc quantitation method using 10.58 mg of dried resin, yielding 0.312 mmol / g (UVarea value at 294 nm: 3327.96, UVarea value at 304 nm: 2998.45). The recovery rate was calculated using the following formula: Recovery rate = 0.312 × (1 ÷ 0.432 - 337.37 × 0.001 + 563.68 × 0.001) = 79.3%. LCMS analysis of the cleavage reaction mixture revealed that the purity of the target product pd2-016 was 96.1 area%, and the over-extended product pd2-016-b was 3.9 area%.

[0533] Analysis conditions: SQDFA05long

[0534] Synthesis of pd2-016-resin under Condition 3. Using the amino acid-loaded resin aa4-004-resin (Fmoc-Pro-O-Trt(2-Cl) resin) (100 mg, 0.432 mmol / g) prepared in Example 1-4 as starting material, pd2-016-resin was synthesized by carrying out Fmoc-MeVal-OH extension (oxyma, 50°C, 10 hours) followed by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours) according to Synthesis Method 1. The loading amount was calculated using the Fmoc quantification method using 11.71 mg of dried resin, yielding 0.314 mmol / g (UVarea value at 294 nm: 3704.39, UVarea value at 304 nm: 3340.1). The recovery rate was calculated using the following formula: Recovery rate = 0.314 × (1 ÷ 0.432 - 337.37 × 0.001 + 563.68 × 0.001) = 79.8%. LCMS analysis of the cleavage reaction mixture revealed that the purity of the target product pd2-016 was 96.2 area%, and the over-extended product pd2-016-b was 3.8 area%.

[0535] Analysis conditions: SQDFA05long

[0536] The above results are summarized in the table below.

[0537] Under Condition 1, in which a dipeptide was supported, the target product was obtained with high recovery and purity. Under Conditions 2 and 3, in which a single amino acid was supported, not only was recovery reduced due to premature cleavage, but the formation of over-elongated products was also observed.

[0538] Synthesis of compound pd2-017-resin, (2S)-1-[(2S)-2-[[(2S,3S)-2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-methylpentanoyl]amino]-3-phenylpropanoyl]pyrrolidine-2-carboxylate-2-chlorotrityl resin (Fmoc-Ile-Phe-Pro-O-Trt(2-Cl)resin)

[0539] Synthesis of pd2-017-resin under Condition 1. Using the dipeptide-loaded resin aa2-024-resin (Fmoc-Phe-Pro-O-Trt(2-Cl) resin) (100 mg, 0.383 mmol / g) prepared in Example 1-4 as starting material, pd2-017-resin was synthesized by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours) according to Synthesis Method 1. The loading amount was calculated using the dried resin (10.41 mg) by Fmoc quantification to be 0.356 mmol / g (UVarea value at 294 nm: 3739.14, UVarea value at 304 nm: 3351.23). The recovery rate was calculated using the following formula according to the recovery rate calculation method. Recovery rate = 0.356 × (1 ÷ 0.383 - 484.54 × 0.001 + 597.7 × 0.001) = 97.0%. Furthermore, when the cleavage reaction solution was analyzed by LCMS, the purity of the target product pd2-017 was found to be 100 area%.

[0540] Analysis conditions: SQDFA05long

[0541] Synthesis of pd2-017-resin under Condition 2. Using the amino acid-loaded resin aa4-004-resin (Fmoc-Pro-O-Trt(2-Cl) resin) (100 mg, 0.432 mmol / g) prepared in Example 1-4 as starting material, pd2-017-resin was synthesized by carrying out Fmoc-Phe-OH extension (HOAt, 40°C, 2.5 hours) followed by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours). The loading amount was calculated using the Fmoc quantitation method using 10.8 mg of dried resin, yielding 0.339 mmol / g (UVarea value at 294 nm: 3688.78, UVarea value at 304 nm: 3317.01). The recovery rate was calculated using the following formula: Recovery rate = 0.339 × (1 ÷ 0.432 - 337.37 × 0.001 + 597.7 × 0.001) = 87.3%. LCMS analysis of the cleavage reaction mixture revealed that the purity of the target product pd2-017 was 97.0 area%, and that the over-extended product pd2-017-b was 3.0 area%.

[0542] Analysis conditions: SQDFA05long

[0543] Synthesis of pd2-017-resin under Condition 3. Using the amino acid-loaded resin aa4-004-resin (Fmoc-Pro-O-Trt(2-Cl) resin) (100 mg, 0.432 mmol / g) prepared in Example 1-4 as starting material, pd2-017-resin was synthesized by carrying out Fmoc-Phe-OH extension (oxyma, 50°C, 10 hours) followed by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours) according to Synthesis Method 1. The loading amount was calculated using the Fmoc quantification method using 10.85 mg of dried resin, yielding 0.320 mmol / g (UVarea value at 294 nm: 3510.64, UVarea value at 304 nm: 3136.09). The recovery rate was calculated using the following formula: Recovery rate = 0.320 × (1 ÷ 0.432 - 337.37 × 0.001 + 597.7 × 0.001) = 82.4%. LCMS analysis of the cleavage reaction mixture revealed that the purity of the target product pd2-017 was 94.8 area%, and that the over-extended product pd2-017-b was 5.2 area%.

[0544] Analysis conditions: SQDFA05long

[0545] The above results are summarized in the table below.

[0546] Under Condition 1, in which a dipeptide was supported, the target product was obtained with high recovery and purity. Under Conditions 2 and 3, in which a single amino acid was supported, not only was recovery reduced due to premature cleavage, but the formation of over-elongated products was also observed.

[0547] Synthesis of compound pd2-018-resin, (2S)-1-[(2S)-2-[[(2S,3S)-2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-methylpentanoyl]amino]-6-[(2-methylpropan-2-yl)oxycarbonylamino]hexanoyl]pyrrolidine-2-carboxylate-2-chlorotrityl resin (Fmoc-Ile-Lys(Boc)-Pro-O-Trt(2-Cl)resin)

[0548] Synthesis of pd2-018-resin under Condition 1. Using the dipeptide-loaded resin aa2-025-resin (Fmoc-Lys(Boc)-Pro-O-Trt(2-Cl) resin) (100 mg, 0.339 mmol / g) prepared in Example 1-4 as starting material, pd2-018-resin was synthesized by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours) according to Synthesis Method 1. The loading amount was calculated using the dried resin (10.97 mg) by Fmoc quantitation to be 0.319 mmol / g (UVarea value at 294 nm: 3517.51, UVarea value at 304 nm: 3171.30). The recovery rate was calculated using the following formula according to the recovery rate calculation method. Recovery rate = 0.319 × (1 ÷ 0.339 - 565.66 × 0.001 + 678.81 × 0.001) = 97.7%. Furthermore, when the cleavage reaction solution was analyzed by LCMS, the purity of the target product pd2-018 was found to be 100 area%.

[0549] Analysis conditions: SQDFA05long

[0550] Synthesis of pd2-018-resin under Condition 2. Using the amino acid-loaded resin aa4-004-resin (Fmoc-Pro-O-Trt(2-Cl) resin) (100 mg, 0.432 mmol / g) prepared in Example 1-4 as starting material, pd2-018-resin was synthesized by carrying out Fmoc-Lys(Boc)-OH extension (HOAt, 40°C, 2.5 hours) followed by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours). The loading amount was calculated using the Fmoc quantitation method with 10.72 mg of dried resin, yielding 0.311 mmol / g (UVarea value at 294 nm: 3353.43, UVarea value at 304 nm: 3026.12). The recovery rate was calculated using the following formula: Recovery rate = 0.311 × (1 ÷ 0.432 - 337.37 × 0.001 + 678.81 × 0.001) = 82.6%. LCMS analysis of the cleavage reaction mixture revealed that the purity of the target product pd2-018 was 95.7 area%, and the over-extended product pd2-018-b was 4.3 area%.

[0551] Analysis conditions: SQDFA05long

[0552] Synthesis of pd2-018-resin under Condition 3. Using the amino acid-loaded resin aa4-004-resin (Fmoc-Pro-O-Trt(2-Cl) resin) (100 mg, 0.432 mmol / g) prepared in Example 1-4 as starting material, pd2-018-resin was synthesized by carrying out Fmoc-Lys(Boc)-OH extension (oxyma, 50°C, 10 hours) followed by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours). The loading amount was calculated using the Fmoc quantification method using dried resin (9.90 mg) to be 0.313 mmol / g (UVarea value at 294 nm: 3111.54, UVarea value at 304 nm: 2815.86). The recovery rate was calculated using the following formula: Recovery rate = 0.313 × (1 ÷ 0.432 - 337.37 × 0.001 + 678.81 × 0.001) = 83.1%. LCMS analysis of the cleavage reaction mixture revealed that the purity of the target product pd2-018 was 92.2 area%, and the over-extended product pd2-018-b was 7.8 area%.

[0553] Analysis conditions: SQDFA05long

[0554] The above results are summarized in the table below.

[0555] Under Condition 1, in which a dipeptide was supported, the target product was obtained with high recovery and purity. Under Conditions 2 and 3, in which a single amino acid was supported, not only was recovery reduced due to premature cleavage, but the formation of over-elongated products was also observed.

[0556] Synthesis of compound pd2-019-resin, 2-[[(2S)-2-[[(2S,3S)-2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-methylpentanoyl]-methylamino]-4-methylpentanoyl]amino]-2-methylpropanoic acid-2-chlorotrityl resin (Fmoc-Ile-MeLeu-Aib-O-Trt(2-Cl) resin)

[0557] Synthesis of pd2-019-resin under Condition 1. Using the dipeptide-loaded resin aa2-018-resin (Fmoc-MeLeu-Aib-O-Trt(2-Cl) resin) (100 mg, 0.300 mmol / g) prepared in Example 1-4 as starting material, pd2-019-resin was synthesized by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours) according to Synthesis Method 1. The loading amount was calculated using the dried resin (12.24 mg) by Fmoc quantitation to be 0.292 mmol / g (UVarea value at 294 nm: 3596.70, UVarea value at 304 nm: 3242.23). The recovery rate was calculated using the following formula according to the recovery rate calculation method. Recovery rate = 0.292 × (1 ÷ 0.300 - 452.54 × 0.001 + 565.7 × 0.001) = 100.6%. Furthermore, when the cleavage reaction solution was analyzed by LCMS, the purity of the target product pd2-019 was found to be 100 area%.

[0558] Analysis conditions: SQDFA05long

[0559] Synthesis of pd2-019-resin under Condition 2. Using the amino acid-loaded resin aa4-005-resin (Fmoc-Aib-O-Trt(2-Cl) resin) (100 mg, 0.390 mmol / g) prepared in Example 1-4 as starting material, pd2-019-resin was synthesized by carrying out the following synthesis procedure: Fmoc-MeLeu-OH extension (HOAt, 40°C, 2.5 hours), followed by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours). The loading amount was calculated using the Fmoc quantitation method with dried resin (9.87 mg) to be 0.334 mmol / g (UVarea value at 294 nm: 3325.50, UVarea value at 304 nm: 2988.67). The recovery rate was calculated using the following formula: Recovery rate = 0.334 × (1 ÷ 0.390 - 325.36 × 0.001 + 565.7 × 0.001) = 93.7%. Furthermore, when the cleavage reaction solution was analyzed by LCMS, the purity of the target product pd2-019 was found to be 100 area%.

[0560] Analysis conditions: SQDFA05long

[0561] Synthesis of pd2-019-resin under Condition 3. Using the amino acid-loaded resin aa4-005-resin (Fmoc-Aib-O-Trt(2-Cl) resin) (100 mg, 0.390 mmol / g) prepared in Example 1-4 as starting material, pd2-019-resin was synthesized by extending the Fmoc-MeLeu-OH moiety (oxyma, 50°C, 10 hours) followed by extending the Fmoc-Ile-OH moiety (HOAt, 40°C, 2.5 hours). The loading amount was calculated using the Fmoc quantification method with dried resin (10.16 mg) to 0.294 mmol / g (UVarea value at 294 nm: 3010.23, UVarea value at 304 nm: 2713.79). The recovery rate was calculated using the following formula: Recovery rate = 0.294 × (1 ÷ 0.390 - 325.36 × 0.001 + 565.7 × 0.001) = 82.5%. Furthermore, when the cleavage reaction solution was analyzed by LCMS, the purity of the target product pd2-019 was found to be 100 area%.

[0562] Analysis conditions: SQDFA05long

[0563] The above results are summarized in the table below.

[0564] Under condition 1, in which a dipeptide was supported, the target product was obtained with high recovery and purity. Under conditions 2 and 3, in which a single amino acid was supported, the target product was obtained with high purity, but a decrease in recovery rate due to premature cleavage was observed.

[0565] Synthesis of compound pd2-020-resin, 2-[[(2S)-2-[[(2S,3S)-2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-methylpentanoyl]-methylamino]-3-methylbutanoyl]amino]acetic acid-2-chlorotrityl resin (Fmoc-Ile-MeVal-Gly-O-Trt(2-Cl)resin)

[0566] Synthesis of pd2-020-resin under Condition 1. Using the dipeptide-loaded resin aa2-019-resin (Fmoc-MeVal-Gly-O-Trt(2-Cl) resin) (100 mg, 0.303 mmol / g) prepared in Example 1-4 as starting material, pd2-020-resin was synthesized by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours) according to Synthesis Method 1. The loading amount was calculated using the dried resin (10.5 mg) by Fmoc quantification to be 0.264 mmol / g (UVarea value at 294 nm: 2792.18, UVarea value at 304 nm: 2514.31). The recovery rate was calculated using the following formula according to the recovery rate calculation method. Recovery rate = 0.264 × (1 ÷ 0.303 - 410.46 × 0.001 + 523.62 × 0.001) = 90.1%. Furthermore, when the cleavage reaction solution was analyzed by LCMS, the purity of the target product pd2-020 was found to be 100 area%.

[0567] Analysis conditions: SQDFA05long

[0568] Synthesis of pd2-020-resin under Condition 2. Using the amino acid-loaded resin aa4-006-resin (Fmoc-Gly-O-Trt(2-Cl) resin) (100 mg, 0.250 mmol / g) prepared in Example 1-4 as starting material, pd2-020-resin was synthesized by elongation of Fmoc-MeVal-OH (HOAt, 40°C, 2.5 hours), followed by elongation of Fmoc-Ile-OH (HOAt, 40°C, 2.5 hours). The loading amount was calculated using the Fmoc quantitation method with dried resin (10.18 mg) to be 0.185 mmol / g (UVarea value at 294 nm: 1889.34, UVarea value at 304 nm: 1720.13). The recovery rate was calculated using the following formula: Recovery rate = 0.185 × (1 ÷ 0.250 - 297.3 × 0.001 + 523.62 × 0.001) = 78.2%. Furthermore, when the cleavage reaction solution was analyzed by LCMS, the purity of the target product pd2-020 was found to be 100 area%.

[0569] Analysis conditions: SQDFA05long

[0570] Synthesis of pd2-020-resin under Condition 3. Using the amino acid-loaded resin aa4-006-resin (Fmoc-Gly-O-Trt(2-Cl) resin) (100 mg, 0.250 mmol / g) prepared in Example 1-4 as starting material, pd2-011-resin was synthesized by carrying out Fmoc-MeVal-OH extension (oxyma, 50°C, 10 hours) followed by Fmoc-Ile-OH extension (HOAt, 40°C, 2.5 hours). The loading amount was calculated using the Fmoc quantification method using dried resin (10.93 mg) to be 0.199 mmol / g (UVarea value at 294 nm: 2175.24, UVarea value at 304 nm: 1978.49). The recovery rate was calculated using the following formula according to the recovery calculation method. Recovery rate = 0.199 × (1 ÷ 0.250 - 297.3 × 0.001 + 523.62 × 0.001) = 84.1%. Furthermore, when the cleavage reaction solution was analyzed by LCMS, the purity of the target product pd2-020 was found to be 100 area%.

[0571] Analysis conditions: SQDFA05long

[0572] The above results are summarized in the table below.

[0573] Under condition 1, in which a dipeptide was supported, the target product was obtained with high recovery and purity. Under conditions 2 and 3, in which a single amino acid was supported, the target product was obtained with high purity, but a decrease in recovery rate due to premature cleavage was observed.

[0574] The results of Example 2 demonstrate that, compared to conventional peptide synthesis methods, in which individual amino acids are supported on a resin and then sequentially elongated, the method of the present invention, in which dipeptides are prepared in advance and then supported on a resin...

Claims

1. A method for producing a peptide compound containing at least one N-alkylamino acid residue, a salt thereof, or a solvate thereof by a solid phase method, characterized in that the peptide is supported on a resin for solid phase synthesis before the first elongation reaction in the solid phase method.

2. A method for producing a peptide compound containing at least one N-alkylamino acid residue, a salt thereof, or a solvate thereof by a solid phase method, the method comprising a step of supporting the peptide on a resin for solid phase synthesis.

3. The method according to claim 1 or 2, wherein the peptide is an oligopeptide comprising two or more amino acid residues.

4. The method according to any one of claims 1 to 3, wherein the C-terminal amino acid residue of the peptide and / or the amino acid residue adjacent to the C-terminal amino acid residue is a non-natural amino acid residue.

5. The method according to any one of claims 1 to 4, wherein the amino acid residue at the C-terminus of the peptide is a non-natural amino acid residue.

6. The method of claim 5, wherein the unnatural amino acid residue is an N-alkyl amino acid residue.

7. The method according to any one of claims 1 to 6, wherein the C-terminal amino acid residue of the peptide is supported on the resin for solid phase synthesis via a carboxyl group bonded to the β-position carbon atom or the γ-position carbon atom of the amino group.

8. The method according to any one of claims 1 to 7, wherein the C-terminal amino acid residue of the peptide and / or the amino acid residue adjacent to the C-terminal amino acid residue has a bulky side chain.

9. The method of claim 8 , wherein the bulky side chain is an optionally substituted branched alkyl group.

10. 10. The method of claim 9, wherein the branched chain alkyl group is attached to the carbon atom alpha to the carboxyl group.

11. The method of claim 10, wherein the branched alkyl group has a branch at the β carbon atom or the γ carbon atom of the carboxyl group.

12. The method according to any one of claims 1 to 11, wherein the resin for solid phase synthesis is a CTC resin, a Wang resin, a SASRIN resin, a Trt resin, a Mtt resin, or a Mmt resin.

13. The method according to claim 12, wherein the resin for solid phase synthesis is a CTC resin.

14. The method according to any one of claims 1 and 3 to 13, comprising a step of supporting the peptide on a resin for solid phase synthesis.

15. The method of any one of claims 1 to 14, further comprising the step of extending the peptide by one or more amino acids.

16. A method for producing a cyclic peptide, a salt thereof, or a solvate thereof, comprising the steps of: Obtaining a peptide compound comprising at least one N-alkylamino acid residue, a salt thereof, or a solvate thereof according to the method of any one of claims 1 to 15; Removing the solid phase synthesis resin; and a step of cyclizing the C-terminal group and the N-terminal group of the peptide compound, a salt thereof, or a solvate thereof to form a cyclic moiety.

17. A method for producing a peptide compound containing at least one N-alkylamino acid residue, a salt thereof, or a solvate thereof by a solid phase method, which is characterized in that the peptide is supported on a resin for solid phase synthesis before the first elongation reaction, thereby improving the recovery rate of the peptide compound compared to the case where amino acids are elongated one residue at a time.

18. A method for producing a peptide compound containing at least one N-alkylamino acid residue, a salt thereof, or a solvate thereof by a solid phase method, which is characterized in that the peptide is supported on a resin for solid phase synthesis before the first elongation reaction, thereby suppressing the production of impurities compared to when amino acids are elongated one residue at a time.

19. A method for producing a peptide compound containing at least one N-alkylamino acid residue, a salt thereof, or a solvate thereof by a solid phase method, which is characterized in that the peptide is supported on a resin for solid phase synthesis before the first elongation reaction, thereby suppressing premature cleavage compared to the case where amino acids are elongated one residue at a time.