Process of preparing a GLP-1r / GIPR agonist by coupling peptide fragments

Abstract

The invention relates to the synthesis of a peptide having the potential to act as GLP- 1R / GIPR agonist via the coupling of suitable functionalized peptide fragments.

Description

[0001] P60004

[0002] Process of preparing a GLP-1R / GIPR agonist by coupling peptide fragments

[0003] FIELD OF THE INVENTION

[0004] The invention relates to the synthesis of a peptide having the potential to act as GLP-1R / GIPR agonist via the coupling of suitable functionalized peptide fragments.

[0005] In particular, the invention relates to a novel process for the preparation of a peptide of formula I (SEQ ID NO:1), or of a pharmaceutically acceptable salt or ester thereof

[0006] X1-P-Ala2-Glu3-Gly4-Thr5-Phe6-Thr7-Ser8-Asp9-Tyr10-Ser11-Ile12-Aib13-Leu14-Asp15-Lys16-Ile17-Ala18-Gln19-Lys20(AEEAc-AEEAc-y-Glu-19-carboxynonadecanoyl)-Ala21-Phe22-Val23-Gln24-Trp25-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31-Ser32-Ser33-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39-NH2

[0007] (I)

[0008] wherein X is

[0009]

[0010] CNand

[0011] AEEAc stands for 2-(2-(2-aminoethoxy)ethoxy)acetic acid.

[0012] BACKGROUND

[0013] The peptide of formula I has the potential to act as GLP-1R / GIPR agonist.

[0014] Glucagon-like peptide- 1 (GLP-1) and gastric inhibitory polypeptide (GIP) are primary incretin hormones secreted from small intestinal L cells and K cells, respectively, on

[0015] 23.01.2026ingestion of glucose or nutrients to stimulate insulin secretion from pancreatic cells. The actions of GIP and GLP-1 are believed to be mediated by their receptors, the GIP receptor (GIPR) and the GLP-1 receptor (GLP-1R), respectively, which both belong to the G-protein coupled receptor family and are expressed in pancreatic cells, as well as in various tissues and organs. GLP-1R / GIPR agonists are compounds that mimic the action of the naturally occurring hormones GLP-1 and GIP. These hormones play a crucial role in regulating blood sugar levels by enhancing insulin secretion in response to meals, inhibiting glucagon release, and slowing gastric emptying. GLP-1R / GIPR agonists are thus useful medicaments in the treatment of type 2 diabetes mellitus to improve glycemic control. Additionally, they have been shown to promote weight loss, which can be beneficial for patients with obesity or those who are overweight. GLP-1R / GIPR agonists are effective in reducing HbAlc levels and have a favorable impact on cardiovascular outcomes in diabetic or overweight patients. Obesity is the most prevalent chronic disease worldwide and is associated with many other diseases.

[0016] Particularly the peptide of formula I is a dual GLP-1R / GIPR agonist, which potently activates production of cyclic adenosine monophosphate (cAMP), but has no or minimal activity on the P-arrestin signaling pathways on either GLP-1R or GIPR. That is, the agonist is fully biased towards cAMP activation, as opposed to being partially biased (i.e., with some P-arrestin activity) or unbiased (i.e., with full P-arrestin activity), on both GLP-1R and GIPR. P-Arrestin activates kinase signaling pathways, but also causes the GLP-1R and GIPR to be turned off and internalized. The peptide of formula I does not cause internalization and consequently, desensitization of either GLP-1R or GIPR, and thus has enhanced signaling efficacy.

[0017] Object of the invention was to provide a novel synthesis approach involving the combination of suitable peptide fragments.

[0018] SUMMARY OF THE INVENTION

[0019] It was found that the object of the invention could be reached with the new process for the preparation of the peptide of formula I (SEQ ID NO: 1), or of a pharmaceutically acceptable salt or ester thereof

[0020] X1-P-Ala2-Glu3-Gly4-Thr5-Phe6-Thr7-Ser8-Asp9-Tyr10-Ser11-Ile12-Aib13-Leu14- Asp15-Lys16-Ile17-Ala18-Gln19-Lys20(AEEAc-AEEAc-y-Glu-19-carboxynonadecanoyl)- Ala21-Phe22-Val23-Gln24-Trp25-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31-Ser32-Ser33-Gly34- Ala35-Pro36-Pro37-Pro38-Ser39-NH2(I)

[0021] wherein X is

[0022]

[0023] CNand

[0024] AEEAc stands for 2-(2-(2-aminoethoxy)ethoxy)acetic acid;

[0025] comprising

[0026] a) coupling of a functionalized peptide fragment Fl (SEQ ID NO:2)

[0027] X1-P-Ala2-Glu3-Gly4-Thr5-Phe6-Thr7-Ser8-Asp9-Tyr10-Ser11-Ile12-Aib13-Leu14-Asp15-Lys16-Ile17-Ala18-OH

[0028] (Fl)

[0029] with a functionalized peptide fragment F2 (SEQ ID NO:3)

[0030] H2N-Gln19-Lys20(AEEAc-AEEAc-y-Glu-19-carboxynonadecanoyl)-Ala21-Phe22-Val23-Gln24-Trp25-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31-Ser32-Ser33-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39-NH2

[0031] (F2)

[0032] or of a functionalized peptide fragment F3 (SEQ ID NO:4)

[0033] X1-P-Ala2-Glu3-Gly4-Thr5-Phe6-Thr7-Ser8-Asp9-Tyr10-Ser11-Ile12-Aib13-Leu14-Asp15-Lys16-Ile17-Ala18-Gln19-Lys20(AEEAc-AEEAc-y-Glu-19-carboxynonadecanoyl)-Ala21-Phe22-OH

[0034] (F3)

[0035] with a functionalized peptide fragment F4 (SEQ ID NO:5)

[0036] H2N-Val23-Gln24-Trp25-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31-Ser32-Ser33-Gly34-Ala35- Pro36-Pro37-Pro38-Ser39-NH2wherein X and AEEAc are as defined above,

[0037] b) cleaving off the protecting groups,

[0038] c) precipitation of the peptide of formula I and optionally

[0039] d) purification and isolation.

[0040] In one further aspect, the invention relates to the following functionalized peptide fragments:

[0041] X1-P-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)- Ser8(OtBu)-Asp9(OMpe)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OMpe)-Lys16(Boc)-Ile17- Ala18-OH

[0042] (Fla) (SEQ ID NO: 6), or

[0043] X1-P-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)- Ser8(OtBu)-Asp9(OMpe)- Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OMpe)-Lys16(Boc)-Ile17- Ala18-O-2-chlorotrityl- amidomethyl resin

[0044] (Fib) (SEQ ID NO:7), or

[0045] X1-P-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)-Ser8(OtBu)-Asp9(OMpe)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OMpe)-Lys16(Boc)-Ile17-Ala18-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-OH

[0046] (F3a) (SEQ ID NO: 10), or

[0047] X1-P-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)-Ser8(OtBu)-Asp9(OMpe)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OMpe)-Lys16(Boc)-Ile17-Ala18-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-O-2-chlorotrityl resin

[0048] (F3b) (SEQ ID NO: 11), or

[0049] X1-P-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)-Ser8(OtBu)-Asp9(OtBu)- Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OtBu)-Lys16(Boc)-Ile17-Ala18-Gln19(Trt)- Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-OH(F3c) (SEQ ID NO: 12), or

[0050] X1-P-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)-Ser8(OtBu)-Asp9(OtBu)- Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OtBu)-Lys16(Boc)-Ile17-Ala18-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-O-2-chlorotrityl resin

[0051] (F3d) (SEQ ID NO: 13), or

[0052] H2N-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O -19-carboxynonadecanoyl)-Ala21-Phe22-Val23-Gln24(Trt)-Trp25(Boc)-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31- Ser32(OtBu)-Ser33(OtBu)-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39(OtBu)-NH2

[0053] (F2a) (SEQ ID NO: 8), or

[0054] H2N-Gln19(Trt)-Lys20(AEEAc-AEEAc- y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-Val23-Gln24(Trt)-Trp25(Boc)-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31- Ser32(OtBu)-Ser33(OtBu)-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39(OtBu)-NH-Xanthenyl linker resin

[0055] (F2b) (SEQ ID NO: 9), or

[0056] H2N-Val23-Gln24(Trt)-Trp25(Boc)-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31-Ser32(OtBu)-Ser33(OtBu)-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39(OtBu)-NH2

[0057] (F4a) (SEQ ID NO: 14), or

[0058] H2N-Val23-Gln24(Trt)-Trp25(Boc)-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31-Ser32(OtBu)- Ser33(OtBu)-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39(OtBu)- NH- Xanthenyl linker resin

[0059] (F4b) (SEQ ID NO: 15).

[0060] Brief Description of the Figures:

[0061] FIG. 1A and FIG. IB show two alternatives of the solid-phase synthesis of the functionalized peptide fragment of formula (F4b) using Xanthenyl linker resin.

[0062] FIG. 2 shows the solid-phase synthesis of the functionalized peptide fragment of formula (F2b) using Xanthenyl linker resin.

[0063] FIG. 3 shows the solid-phase synthesis of the functionalized peptide fragment of formula (Fib) using 2-chlorotrityl-amidomethyl resin.In FIG. 4A and FIG. 4B two alternatives of the solid-phase synthesis of the functionalized peptide fragment of formula (F3b) and the functionalized peptide fragment of formula (F3d), respectively, using 2-chlorotrityl resin are shown.

[0064] FIG. 5 is a reaction scheme showing the release of the functionalized peptide fragment (F2a) by soft cleavage from the resin.

[0065] FIG. 6A and FIG. 6B show two alternatives of the release of the functionalized peptide fragment of formula (F4a) by soft cleavage from the resin.

[0066] In FIG. 7 the release of the functionalized peptide fragment of formula (Fla) by soft cleavage from the resin is shown.

[0067] FIG. 8A and FIG. 8B show two alternatives of the release of the functionalized peptide fragment of formula (F3a) or the functionalized peptide fragment of formula (F3c), respectively, by soft cleavage from the resin.

[0068] FIG. 9 shows the coupling procedure of the functionalized peptide fragment of formula (Fla) with the functionalized peptide fragment of formula (F2a) followed by full cleavage of the protecting groups.

[0069] FIG. 10A and FIG. 10B show two alternatives of the coupling procedure of the functionalized peptide fragment of formula (F3a) or the functionalized peptide fragment of formula (F3c) with the functionalized peptide fragment of formula (F4a) followed by full cleavage of the protecting groups.

[0070] DETAILED DESCRIPTION OF THE INVENTION

[0071] The following definitions are set forth to illustrate and define the meaning and scope of the various terms used to describe the invention herein.

[0072] The term "pharmaceutically acceptable salt" refers to those salts which retain the biological effectiveness and properties of the free bases or free acids, which are not biologically or otherwise undesirable. The salts are formed with inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid and the like, in particular hydrochloric acid, and organic acids such as acetic acid, trifluoroacetic acid, propionic acid, glycolic acid, pyruvic acid, oxalic acid, maleic acid, malonic acid, succinic acid, fumaric acid, tartaric acid, citric acid, benzoic acid, cinnamic acid, mandelic acid, methanesulfonic acid, ethanesulfonic acid, p-toluenesulfonic acid, salicylic acid, N-acetylcysteine and the like. In addition, these salts may be prepared by addition of an inorganic base or an organic base to the free acid. Salts derived from an inorganic base include but are not limited to, the sodium, potassium, lithium, ammonium, calcium, magnesium salts and the like. Salts derived from organic bases include but are not limited to salts of primary, secondary, and tertiary amines, substituted amines including naturally occurring substituted amines, cyclic amines and basic ion exchange resins, such as isopropylamine, trimethylamine, diethylamine, triethylamine, tripropylamine, ethanolamine, lysine, arginine, 7V-ethylpiperidine, piperidine, polyimine resins and the like.

[0073] The term “salt” in the context of the present invention encompasses typical salts of carboxylic acids, which can be formed with inorganic bases such as with alkali hydroxide, like sodium hydroxide or with organic bases such as with amines, like ammonia. Further viable examples can be found in the definition of the term "pharmaceutically acceptable salt".

[0074] The term “alkyl” stands for a linear or branched alkyl group, usually of 1 to 6 C-atoms. Representatives are methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, i-butyl or t-butyl, pentyl and its isomers and hexyl and its isomers. In the context of the present invention lower alkyl groups of 1 to 4 C-atoms are preferred.

[0075] The term “ester protecting group” refers to protecting groups of the carboxylic acid functionalities of the amino acid, which typically can be cleaved under acidic conditions. Commonly used is tert-butyl (tBu) or 3 -methyl-pent-3 -yl (Mpe) which are cleavable with a strong acid, such as e.g. with trifluoroacetic acid.

[0076] The term “solid phase peptide synthesis (SPPS) conditions” in the context of the present invention refers to specific parameters and reagents for assembling the peptide fragments on a solid support. These conditions are tailored to ensure efficient coupling, minimize side reactions, and yield high-purity peptides, varying based on the peptide sequence, scale, and desired synthesis outcome. Key components include, but are not limited to the solid support, suitable protecting groups for the amino acids, suitable coupling agents and solvents, procedures to eliminate by-products and suitable cleavage conditions to remove the peptide from the resin and deprotect side chains.

[0077] The solid support typically consists of a polymeric resin, most commonly low crosslinked polystyrene beads, which is equipped with reactive groups to enable covalent binding between the carboxyl group of the first amino acid of the nascent peptide chain and the resin through a linker. The most common polymeric solid support used is a resin composed of a 1-2% divinylbenzene - cross-linked polystyrene. Furthermore, a resin is composed of thepolymeric solid support linked permanently to a linker (bifunctional spacer, or handle) that facilitates temporary anchoring of the first amino acid to the polymeric solid support.

[0078] Depending on the type of linker, the C-terminus of the first amino acid is anchored to the solid support as an amide, ester, thioester, O- substituted oxime, or hydrazide. For instance, benzhydrylamine resins (Rink amide resin) or xanthenyl linker resins or Sieber amide resin can be used. Alternatively, the Ramage amide resin or a tricyclic amide linker resin can be applied. All these resins will form an amide with the first amino acid. After cleavage from solid support, the peptide will comprise a C-terminal amide group. For peptide acid fragments, chlorotrityl resins (CTC resins) such as 2-chlorotrityl resin or 2-chlorotrityl-amidomethyl resin are used.

[0079] Each amino acid to be coupled to the peptide chain A-terminus must bear an appropriate protective group on its a-amino group and potentially on its side chain. The base-labile fluorenylm ethyl oxy carbonyl (Fmoc) group is commonly used to protect the a-amino group of the incoming amino acid. The repeated cycles involve alternate deprotection and coupling reactions. As an alternative, base-labile protecting group Bsmoc (1,1-dioxobenzo[b]thiophene-2-ylmethyloxycarbonyl) can be used for certain couplings.

[0080] Deprotection of Fmoc and exposing the amino group for the next coupling step can be accomplished by a reaction with the basic piperidine in a polar, aprotic solvent. As a rule, solutions of 10 to 30% (v / v) piperidine in DMF are used. OxymaPure (ethyl 2-cyano-2-(hydroxyimino)acetate) may be added as an additive.

[0081] The coupling reactions as a rule require activation of the carboxylic acid moiety with coupling agents or activators such as AA'-diisopropylcarbodiimide (DIC) to support an effective amide bond formation. Conditions of a coupling reaction determine the acylation rate, as well as the extent of side reactions, such as racemization.

[0082] Racemization can be suppressed with racemization-suppressing additives such as 1-hydroxy -benzotriazole (HOBt), l-hydroxy-7-aza-benzotriazole (HO At) and ethyl cyano(hydroxyimino)acetate (OxymaPure). OxymaPure has been developed as an efficient additive for carbodiimide-based coupling.

[0083] The combination AA'-diisopropylcarbodiimide (DIC) and ethyl cyano(hydroxyimino)acetate (OxymaPure) has been proven to be the coupling agent / additive combination of choice. Typically, the activation process takes place in the presence of a polar aprotic solvent, such as DMF.At the end of the synthesis, the crude peptides can be cleaved from the solid support while simultaneously removing all protecting groups, typically using an acidic reagent such as trifluoroacetic acid, and the crude peptide can be precipitated and optionally purified.

[0084] While the optimum reaction conditions of the SPPS must be adapted for every peptide, the general SPPS method is well known in the art and is described for instance in detail in W. C. Chan and P. D. White, Fmoc Solid Phase Peptide Synthesis: A Practical Approach, Oxford University Press Inc., 1999.

[0085] In one aspect, the invention relates to a process for the preparation of the peptide of formula I (SEQ ID NO:1), or of a pharmaceutically acceptable salt or ester thereof

[0086] X1-P-Ala2-Glu3-Gly4-Thr5-Phe6-Thr7-Ser8-Asp9-Tyr10-Ser11-Ile12-Aib13-Leu14- Asp15-Lys16-Ile17-Ala18-Gln19-Lys20(AEEAc-AEEAc-y-Glu-19-carboxynonadecanoyl)- Ala21-Phe22-Val23-Gln24-Trp25-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31-Ser32-Ser33-Gly34- Ala35-Pro36-Pro37-Pro38-Ser39-NH2

[0087] (I)

[0088] wherein X is

[0089]

[0090] CNand

[0091] AEEAc stands for 2-(2-(2-aminoethoxy)ethoxy)acetic acid;

[0092] comprising

[0093] a) coupling of a functionalized peptide fragment Fl (SEQ ID NO:2)

[0094] X1-P-Ala2-Glu3-Gly4-Thr5-Phe6-Thr7-Ser8-Asp9-Tyr10-Ser11-Ile12-Aib13-Leu14-Asp15- Lys16-Ile17-Ala18-OH

[0095] (Fl)

[0096] with a functionalized peptide fragment F2 (SEQ ID NO:3)H2N-Gln19-Lys20(AEEAc-AEEAc-y-Glu-19-carboxynonadecanoyl)-Ala21-Phe22-Val23-Gln24-Trp25-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31-Ser32-Ser33-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39-NH2

[0097] (F2)

[0098] wherein X and AEEAc are as defined above,

[0099] or of a functionalized peptide fragment F3 (SEQ ID NO:4)

[0100] X1-P-Ala2-Glu3-Gly4-Thr5-Phe6-Thr7-Ser8-Asp9-Tyr10-Ser11-Ile12-Aib13-Leu14-Asp15-Lys16-Ile17-Ala18-Gln19-Lys20(AEEAc-AEEAc-y-Glu-19-carboxynonadecanoyl)-Ala21-Phe22-OH

[0101] (F3)

[0102] with a functionalized peptide fragment F4 (SEQ ID NO:5)

[0103] H2N-Val23-Gln24-Trp25-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31-Ser32-Ser33-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39-NH2

[0104] (F4),

[0105] wherein X and AEEAc are as defined above,

[0106] and

[0107] b) cleaving off the protecting groups,

[0108] c) precipitation of the peptide of formula I and optionally

[0109] d) purification and isolation.

[0110] In general, the coupling of the peptide fragments is performed in the presence of a coupling agent, an organic base and an organic solvent.

[0111] Suitable coupling agents can be selected from benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate (BOP), benzotriazol-1-yloxytripyrrolidinophosphonium hexafluorophosphate (PyBOP), bromotripyrrolidinophosphonium hexafluorophosphate (PyBrOP), (7-azabenzotriazol-l-yloxy)tripyrrolidinophosphonium hexafluorophosphate (PyAOP), / ' / -[( / / / -benzotriazol- l-yl)(dimethylamino)methylene]-A-methylmethanaminium tetrafluoroborate A-oxide (TBTU), 2-(7A-benzotriazole-l-yl)-l,l,3,3-tetramethylaminium hexafluorophosphate (HBTU), 1-[bis(dimethylamino)methylene]-777-l,2,3-triazolo[4,5-b]pyridinium 3-oxide hexafluorophosphate, A-[(dimethylamino)-3A-l,2,3-triazolo-[4,5-b]pyridin-l-ylmethylene]-A-methylmethanaminium hexafluorophosphate A-oxide (HATU), propanephosphonic acid anhydride (T3P), < -(2-oxo-l(277)pyridyl)-AAA'A'-tetramethyluronium tetrafluoroborate (TPTU), l-cyano-2-ethoxy-2-oxoethylidenaminooxy)dimethylamino-morpholino-carbenium hexafluorophosphate (COMU), 1 -cyano-2-ethoxy-2-oxoethylideneaminooxy-tris-pyrrolidino-phosphonium hexafluorophosphate (PyOXIM), pentafluorophenyl diphenylphosphinate (FDPP), diphenylphosphoryl azide (DPP A), 4-(4,6-dimethoxy-l,3,5-triazin-2-yl)-4-methyl-morpholinium chloride (DMTMM) or from a combination of N, A'-diisopropylcarbodiimide (DIC) with A-hydroxysduccinimide, with 4-(dimethylamino)pyridine (DMAP), with 2-hydroxypyri dine- -oxide (HOPO) or with (ethyl-cyano (hydroximino)acetate) (OxymaPure) or from a combination of l-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) with 2-hydroxypyridine-A-oxide (HOPO).

[0112] Preferred coupling agents are the combination of AA'-diisopropylcarbodiimide (DIC) and 2-hydroxypyridine-A-oxide (HOPO) or l-cyano-2-ethoxy-2-oxoethylideneaminooxy-tris-pyrrolidino-phosphonium hexafluorophosphate (PyOxim).

[0113] The organic base is usually selected from AA-diisopropylethylamine, A-methylmorpholine (NMM), A-methylimidazole (NMI), 2-6-lutidine, 2,4,6-collidine or from triethylamine. Preferably, the organic base is AA-diisopropylethylamine or 2,4,6-collidine.

[0114] The organic solvent can be selected from AA-dimethylformamide, toluene, acetonitrile, dimethyl sulfoxide, methylene chloride or mixtures thereof. The preferred organic solvent is methylene chloride or a mixture of dimethyl sulfoxide and methylene chloride.

[0115] The reaction temperature can be chosen between 0°C and 30°C, typically the process is run at ambient temperature.

[0116] The term “functionalized peptide” as used herein means that the functional groups of the amino acids (i.e. the functional groups in the side chains of the amino acids) included in the various peptide fragments used for building up the peptide of formula I are protected with suitable protecting groups, e.g. Thr, Ser, Tyr, Glu with OtBu, Trp or Lys with Boc, Gin with Trt, and Asp with OtBu or OMpe.In one particular aspect, the functionalized peptide fragment Fl has the formula Fla (SEQ ID NO: 6)

[0117] X1-P-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)- Ser8(OtBu)-Asp9(OMpe)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OMpe)-Lys16(Boc)-Ile17- Ala18-OH

[0118] (Fla),

[0119] and the functionalized peptide fragment F2 has the formula F2a (SEQ ID NO:8)

[0120] H2N-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-Val23-Gln24(Trt)-Trp25(Boc)-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31- Ser32(OtBu)-Ser33(OtBu)-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39(OtBu)-NH2

[0121] (F2a).

[0122] In one further particular aspect, the functionalized peptide fragment F3 has the formula F3a (SEQ ID NO: 10)

[0123] X1-P-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)-Ser8(OtBu)-Asp9(OMpe)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OMpe)-Lys16(Boc)-Ile17-Ala18-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O -19-carboxynonadecanoyl)-Ala21-Phe22-OH

[0124] (F3a), or

[0125] the formula F3c (SEQ ID NO: 12)

[0126] X1-P-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)-Ser8(OtBu)-Asp9(OtBu)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OTBu)-Lys16(Boc)-Ile17-Ala18-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-OH

[0127] (F3c),

[0128] and the functionalized peptide fragment F4 has the formula F4a (SEQ ID NO: 14)

[0129] H2N-Val23-Gln24(Trt)-Trp25(Boc)-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31-Ser32(OtBu)-Ser33(OtBu)-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39(OtBu)-NH2

[0130] (F4a),

[0131] wherein X and AEEAc are as defined above.In one aspect, the invention relates to a process for the preparation of the peptide of formula I (SEQ ID NO:1), or of a pharmaceutically acceptable salt or ester thereof

[0132] X1-P-Ala2-Glu3-Gly4-Thr5-Phe6-Thr7-Ser8-Asp9-Tyr10-Ser11-Ile12-Aib13-Leu14- Asp15-Lys16-Ile17-Ala18-Gln19-Lys20(AEEAc-AEEAc-y-Glu-19-carboxynonadecanoyl)- Ala21-Phe22-Val23-Gln24-Trp25-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31-Ser32-Ser33-Gly34- Ala35-Pro36-Pro37-Pro38-Ser39-NH2

[0133] (I)

[0134] wherein X is

[0135]

[0136] CNand

[0137] AEEAc stands for 2-(2-(2-aminoethoxy)ethoxy)acetic acid;

[0138] comprising

[0139] a) coupling of a functionalized peptide fragment Fl (SEQ ID NO:2)

[0140] X1-P-Ala2-Glu3-Gly4-Thr5-Phe6-Thr7-Ser8-Asp9-Tyr10-Ser11-Ile12-Aib13-Leu14-Asp15-Lys16-Ile17-Ala18-OH

[0141] (Fl)

[0142] with a functionalized peptide fragment F2 (SEQ ID NO:3)

[0143] H2N-Gln19-Lys20(AEEAc-AEEAc-y-Glu-19-carboxynonadecanoyl)-Ala21-Phe22-Val23-Gln24-Trp25-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31-Ser32-Ser33-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39-NH2

[0144] (F2)

[0145] wherein X and AEEAc are as defined above, and

[0146] b) cleaving off the protecting groups,

[0147] c) precipitation of the peptide of formula I, and optionallyd) purification / isolation.

[0148] In another aspect, the invention relates to a process for the preparation of the peptide of formula I (SEQ ID NO:1), or of a pharmaceutically acceptable salt or ester thereof

[0149] X1-P-Ala2-Glu3-Gly4-Thr5-Phe6-Thr7-Ser8-Asp9-Tyr10-Ser11-Ile12-Aib13-Leu14- Asp15-Lys16-Ile17-Ala18-Gln19-Lys20(AEEAc-AEEAc-y-Glu-19-carboxynonadecanoyl)- Ala21-Phe22-Val23-Gln24-Trp25-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31-Ser32-Ser33-Gly34- Ala35-Pro36-Pro37-Pro38-Ser39-NH2

[0150] (I)

[0151] wherein X is

[0152]

[0153] CNand

[0154] AEEAc stands for 2-(2-(2-aminoethoxy)ethoxy)acetic acid;

[0155] comprising

[0156] a) coupling of a functionalized peptide fragment F3 (SEQ ID NO:4)

[0157] X1-P-Ala2-Glu3-Gly4-Thr5-Phe6-Thr7-Ser8-Asp9-Tyr10-Ser11-Ile12-Aib13-Leu14-Asp15-Lys16-Ile17-Ala18-Gln19-Lys20(AEEAc-AEEAc-y-Glu-19-carboxynonadecanoyl)-Ala21-Phe22-OH

[0158] (F3)

[0159] with a functionalized peptide fragment F4 (SEQ ID NO:5)

[0160] H2N-Val23-Gln24-Trp25-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31-Ser32-Ser33-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39-NH2

[0161] (F4),

[0162] wherein X and AEEAc are as defined above, and

[0163] b) cleaving off the protecting groups,c) precipitation of the peptide of formula I, and optionally

[0164] d) purification / isolation.

[0165] Thus, in one preferred aspect of the invention, the functionalized peptide fragment Fl has the formula Fla (SEQ ID NO: 6)

[0166] X1-P-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)- Ser8(OtBu)-Asp9(OMpe)- Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OMpe)-Lys16(Boc)-Ile17- Ala18-OH

[0167] (Fla)

[0168] and the functionalized peptide fragment F2 has the formula F2a (SEQ ID NO:8)

[0169] H2N-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O -19-carboxynonadecanoyl)-Ala21-Phe22-Val23-Gln24(Trt)-Trp25(Boc)-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31- Ser32(OtBu)-Ser33(OtBu)-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39(OtBu)-NH2

[0170] (F2a),

[0171] wherein X and AEEAc are as defined above.

[0172] In another preferred aspect of the invention, the functionalized peptide fragment F3 has the formula F3a (SEQ ID NO: 10)

[0173] X1-P-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)-Ser8(OtBu)-Asp9(OMpe)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OMpe)-Lys16(Boc)-Ile17-Ala18-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-OH

[0174] (F3a), or

[0175] the formula F3c (SEQ ID NO: 12)

[0176] X1-P-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)-Ser8(OtBu)-Asp9(OtBu)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OTBu)-Lys16(Boc)-Ile17-Ala18-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-OH

[0177] (F3c),

[0178] and the functionalized peptide fragment F4 has the formula F4a (SEQ ID NO: 14)H2N-Val23-Gln24(Trt)-Trp25(Boc)-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31-Ser32(OtBu)-Ser33(OtBu)-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39(OtBu)-NH2

[0179] (F4a),

[0180] wherein X and AEEAc are as defined above.

[0181] Formation of the peptide of formula I by cleavage of the protecting groups in step b) can be performed with a mixture of TFA and water and optionally at least one additional scavenger. A suitable scavenger is TIS (triisopropylsilane). A v / v mixture of TFA / water of 90 to 99: 10 to 1, more preferably of 93 to 97: 7 to 3 or a v / v / v mixture of TFA / water / TIS of 90:5:5 can be used.

[0182] The precipitation of the resulting peptide of formula I in step c) can be accomplished with a suitable organic solvent such as diisopropyl ether (IPE), methyl tert-butyl ether (MTBE), cyclopentyl methylether (CPME), n-heptane or diethylether.

[0183] The isolation in step d) can be carried by methods known to the skilled in the art, such as by centrifugation or by filtration. In one aspect, the centrifugation is carried out with up to 3500 rpm and at a temperature at 5 to 15 °C for 5 to 15 minutes.

[0184] In a further aspect of the invention, the peptide fragments Fl, Fla, F2, F2a, F3, F3a, F4 and F4a are prepared under the conditions of solid phase peptide synthesis on a resin and thereafter cleaved from the resin.

[0185] The cleaving off of the functionalized peptide fragments Fl, Fla, F2, F2a, F3, F3a, F4 and F4a from the resin has to be accomplished in a soft manner ensuring that the functionalization, i.e. the protecting groups of the fragments are not affected.

[0186] Typically, a low concentrated solution of 0.5 % to 10% TFA in an organic solvent is applied (“low concentration TFA”). For the cleavage from the Xanthenyl linker resin a solution of 2 % to 6 % TFA and for the cleavage from the 2-chlorotrityl resin solution of 0.5 % to 2.5 % TFA can be applied.

[0187] Suitable organic solvents are methylene chloride, toluene or ethyl acetate, preferably methylene chloride has been found to be advantageous.

[0188] As previously described, the solid phase peptide synthesis is preferably a Fmoc- solid phase peptide synthesis on a suitable resin.Typically chlorotrityl resins (CTC resins) such as 2 -chlorotrityl resin or 2-chlorotrityl-amidomethyl resin are used for peptide acid fragments, whereas amide resins such as benzhydrylamine resins (Rink amide resin), xanthenyl linker resins, the Sieber amide resin or the Ramage amide resin are used for peptide amide fragments. 2-chlorotrityl resin and 2-chlorotrityl-amidomethyl resin are preferred resins for peptide acid fragments. The xanthenyl linker resin is preferred for the peptide amide fragments.

[0189] In one particular aspect, the preparation of functionalized peptide fragment Fl, in particular fragment Fla (SEQ ID NO:6), comprises sequential coupling of the following functionalized building blocks on a resin, particularly on a 2-chlorotrityl-amidomethyl resin.

[0190] Aminoacid # Cycle# Building Block

[0191] 18 H- Al a-2 -chi orotrity 1 -ami dom ethyl

[0192] resin

[0193] 17 1 Fmoc-L-Ile-OH

[0194] 16 2 Fmoc-L-Ly s(B oc)-OH

[0195] 15 3 Fmoc-L- Asp(OMpe)-OH

[0196] 14 4 Fmoc-L-Leu-OH

[0197] 13 5 Fmoc-Aib-OH

[0198] 12 6 Fmoc-L-Ile-OH

[0199] 11 7 Fmoc-L-S er(OtBu)-OH

[0200] 10 8 Fmoc-L-Tyr-OH

[0201] 9 9 Fmoc-L- Asp(OMpe)-OH

[0202] 8 10 Fmoc-L-S er(OtBu)-OH

[0203] 7 11 Fmoc-L-Thr(OtBu)-OH

[0204] 6 12 Fmoc-L-Phe-OH

[0205] 5 13 Fmoc-L-Thr(OtBu)-OH

[0206]

[0207] 4 14 Fmoc-Gly-OH

[0208] 3 15 Fmoc-L-Glu(OtBu)-OH H2O 2 16 Fmoc-β-Ala-OH

[0209] 1 17 2-(3 -cy ano-5 -fluorophenyl)-2- methylpropanoic acid

[0210]

[0211] In a further particular aspect, the preparation of functionalized peptide fragment F2, in particular fragment F2a (SEQ ID NO:8), comprises sequential coupling of the following functionalized building blocks on a resin, particularly on a Xanthenyl linker resin:

[0212] Aminoacid # Cycle# Building Block

[0213] Xanthenyl linker resin

[0214] 39 1 Fmoc-L-S er(OtBu)-OH

[0215] 38-37 2 Fmoc-L-Pro-L-Pro-OH

[0216] 36-35 3 Fmoc-L-Ala-L-Pro-OH

[0217] 34 4 Fmoc-Gly-OH

[0218] 33 5 Fmoc-L-S er(OtBu)-OH

[0219] 32 6 Fmoc-L-S er(OtBu)-OH

[0220] 31 7 Fmoc-L-Pro-OH H2O

[0221] 30-29 8 Fmoc-Gly-Gly-OH

[0222] 28 9 Fmoc-L-Ala-OH H2O

[0223] 27 10 Fmoc-L-Ile-OH

[0224] 26 11 Fmoc-L-Leu-OH

[0225] 25 12 Fmoc-L-Trp(Boc)-OH

[0226]

[0227] 24 13 Fmoc-L-Gln(Trt)-OH

[0228] 23 14 Fmoc-L-Val-OH

[0229] 22 15 Fmoc-L-Phe-OH

[0230] 21 16 Fmoc-L-Ala-OH H2O

[0231] 20 17 ivDde-Lys(Fmoc)-OH

[0232] side-chain 18 tBu-O- 19-carboxy-nonadecanoyl-L- Glu(AEEAc-AEEAc-OH)-OtBu

[0233] 19 19 Fmoc-L-Gln(Trt)-OH

[0234]

[0235] In another particular aspect, the preparation of functionalized peptide fragment F3, in particular fragment F3a (SEQ ID NO: 10), comprises sequential coupling of the following functionalized building blocks on a resin, particularly on a 2-chlorotrityl resin

[0236] Aminoacid # Cycle# Building Block

[0237] 22 H-Phe-2-chlorotrityl resin

[0238] 21 1 Fmoc-L-Ala-OH H2O

[0239] 20 2 Fmoc-Lys(ivDde)-OH

[0240] 19 3 Fmoc-L-Gln(Trt)-OH

[0241] 18 4 Fmoc-L-Ala-OH-H2O

[0242] 17 5 Fmoc-L-Ile-OH

[0243] 16 6 Fmoc-L-Lys(Boc)-OH

[0244] 15 7 Fmoc-L-Asp(OMpe)-OH

[0245] 14 8 Fmoc-L-Leu-OH

[0246] 13 9 Fmoc-Aib-OH

[0247]

[0248] 12 10 Fmoc-L-Ile-OH

[0249] 11 11 Fmoc-L-Ser(OtBu)-OH

[0250] 10 12 Fmoc-L-Tyr-OH

[0251] 9 13 Fmoc-L-Asp(OMpe)-OH

[0252] 8 14 Fmoc-L-Ser(OtBu)-OH

[0253] 7 15 Fmoc-L-Thr(OtBu)-OH

[0254] 6 16 Fmoc-L-Phe-OH

[0255] 5 17 Fmoc-L-Thr(OtBu)-OH

[0256] 4 18 Fmoc-Gly-OH

[0257] 3 19 Fmoc-L-Glu(OtBu)-OH H2O

[0258] 2 20 Fmoc-P-Ala-OH

[0259] 1 21 2-(3 -cy ano-5 -fluorophenyl)-2- methylpropanoic acid

[0260] subsequent sequential built up of side

[0261] chain on Lys20

[0262] 20.1 22 Fmoc-AEEAc-OH

[0263] 20.2 23 Fmoc-AEEAc-OH

[0264] 20.3 24 Fmoc-Glu-OtBu

[0265] 20.4 25 Eicosanedioic acid mono-te / 7-butyl ester

[0266]

[0267] A particular aspect of the preparation of the functionalized peptide fragment F3, in particular fragment F3a, is that initially a sequential coupling of the functionalized building blocks 1 to 22 on the resin takes place.In a subsequent step the Lys20(ivDde) protecting group is removed and the side chain building blocks 20.1 to 20.4 are added.

[0268] Alternatively, in another particular aspect, the preparation of functionalized peptide fragment F3, in particular fragment F3a (SEQ ID NO:10), comprises sequential coupling of the following functionalized building blocks on a resin, particularly on a 2-chlorotrityl resin

[0269] Aminoacid # Cycle# Building Block

[0270] 2-chlorotrityl resin

[0271] 22 1 Fmoc-L-Phe-OH

[0272] 21 2 Fmoc-L-Ala-OH H2O

[0273] 20 3 Bsmoc-Lys(AEEAc-AEEAc-y-Glu(O- tBu)- 19-carboxy-nonadecanoyl-O-tBu)- OH

[0274] 19 4 Fmoc-L-Gln(Trt)-OH

[0275] 18 5 Fmoc-L-Ala-OH-H2O

[0276] 17 6 Fmoc-L-Ile-OH

[0277] 16 7 Fmoc-L-Lys(Boc)-OH

[0278] 15 8 Fmoc-L-Asp(OMpe)-OH

[0279] 14 9 Fmoc-L-Leu-OH

[0280] 13 10 Fmoc-Aib-OH

[0281] 12 11 Fmoc-L-Ile-OH

[0282] 11 12 Fmoc-L-Ser(OtBu)-OH

[0283] 10 13 Fmoc-L-Tyr-OH

[0284] 9 14 Fmoc-L-Asp(OMpe)-OH

[0285]

[0286] 8 15 Fmoc-L-Ser(OtBu)-OH

[0287] 7 16 Fmoc-L-Thr(OtBu)-OH

[0288] 6 17 Fmoc-L-Phe-OH

[0289] 5 18 Fmoc-L-Thr(OtBu)-OH

[0290] 4 19 Fmoc-Gly-OH

[0291] 3 20 Fmoc-L-Glu(OtBu)-OH H2O

[0292] 2 21 Fmoc-β-Ala-OH

[0293] 1 22 2-(3 -cy ano-5 -fluorophenyl)-2- methylpropanoic acid

[0294]

[0295] According to this process alternative the Lys20side chain can directly be introduced via the Bsmoc-Lys(AEEAc-AEEAc-y-Glu(O-tBu)- 19-carboxy-nonadecanoyl-O-tBu)-OH fragment in cycle 3, without requiring the sequential assembly of the side chain described in the previous process.

[0296] Alternatively, in another particular aspect, the preparation of functionalized peptide fragment F3, in particular fragment F3c (SEQ ID NO: 12), comprises sequential coupling of the following functionalized building blocks on a resin, particularly on a 2-chlorotrityl resin, wherein Fmoc-L-Asp(OtBu)-OH is used as building block.

[0297] Aminoacid # Cycle# Building Block

[0298] 2-chlorotrityl resin

[0299] 22 1 Fmoc-L-Phe-OH

[0300] 21 2 Fmoc-L-Ala-OH H2O

[0301] 20 3 Bsmoc-Lys(AEEAc-AEEAc-y-Glu(O- tBu)- 19-carboxy-nonadecanoyl-O-tBu)- OH

[0302] 19 4 Fmoc-L-Gln(Trt)-OH

[0303]

[0304] 18 5 Fmoc-L-Ala-OH-H2O

[0305] 17 6 Fmoc-L-Ile-OH

[0306] 16 7 Fmoc-L-Lys(Boc)-OH

[0307] 15 8 Fmoc-L-Asp(OtBu)-OH

[0308] 14 9 Fmoc-L-Leu-OH

[0309] 13 10 Fmoc-Aib-OH

[0310] 12 11 Fmoc-L-Ile-OH

[0311] 11 12 Fmoc-L-Ser(OtBu)-OH

[0312] 10 13 Fmoc-L-Tyr-OH

[0313] 9 14 Fmoc-L-Asp(OtBu)-OH

[0314] 8 15 Fmoc-L-Ser(OtBu)-OH

[0315] 7 16 Fmoc-L-Thr(OtBu)-OH

[0316] 6 17 Fmoc-L-Phe-OH

[0317] 5 18 Fmoc-L-Thr(OtBu)-OH

[0318] 4 19 Fmoc-Gly-OH

[0319] 3 20 Fmoc-L-Glu(OtBu)-OH H2O

[0320] 2 21 Fmoc-β-Ala-OH

[0321] 1 22 2-(3 -cy ano-5 -fluorophenyl)-2- methylpropanoic acid

[0322]

[0323] In a further particular aspect, the preparation of functionalized peptide fragment F4, in particular fragment F4a (SEQ ID NO: 14), comprises sequential coupling of the following functionalized building blocks on a resin, particularly on a Xanthenyl linker resin.Aminoacid # Cycle# Building Block

[0324] Xanthenyl linker resin

[0325] 39 1 Fmoc-L-Ser(OtBu)-OH

[0326] 38-37 2 Fmoc-L-Pro-L-Pro-OH

[0327] 36-35 3 Fmoc-L-Ala-L-Pro-OH

[0328] 34 4 Fmoc-Gly-OH

[0329] 33 5 Fmoc-L-Ser(OtBu)-OH

[0330] 32 6 Fmoc-L-Ser(OtBu)-OH

[0331] 31 7 Fmoc-L-Pro-OH H2O

[0332] 30-29 8 Fmoc-Gly-Gly-OH

[0333] 28 9 Fmoc-L-Ala-OH H2O

[0334] 27 10 Fmoc-L-Ile-OH

[0335] 26 11 Fmoc-L-Leu-OH

[0336] 25 12 Fmoc-L-Trp(Boc)-OH

[0337] 24 13 Fmoc-L-Gln(Trt)-OH

[0338] 23 14 Fmoc-L-Val-OH

[0339]

[0340] Alternatively, the peptide fragment F4a can be assembled as follows:

[0341] Aminoacid # Cycle# Building Block

[0342] Xanthenyl linker resin

[0343] 39 1 Fmoc-L-Ser(OtBu)-OH

[0344] 38 2 Fmoc-L-Pro-OH H2O

[0345]

[0346] 37-36 3 Fmoc-L-Pro-L-Pro-OH

[0347] 35 4 Fmoc-L-Ala-OH H2O

[0348] 34 5 Fmoc-Gly-OH

[0349] 33 6 Fmoc-L-Ser(OtBu)-OH

[0350] 32 7 Fmoc-L-Ser(OtBu)-OH

[0351] 31 8 Fmoc-L-Pro-OH H2O

[0352] 30-29 9 Fmoc-Gly-Gly-OH

[0353] 28 10 Fmoc-L-Ala-OH H2O

[0354] 27 11 Fmoc-L-Ile-OH

[0355] 26 12 Fmoc-L-Leu-OH

[0356] 25 13 Fmoc-L-Trp(Boc)-OH

[0357] 24 14 Fmoc-L-Gln(Trt)-OH

[0358] 23 15 Fmoc-L-Val-OH

[0359]

[0360] In another aspect, the invention relates to the following functionalized peptide fragments:

[0361] X1-P-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)- Ser8(OtBu)-Asp9(OMpe)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OMpe)-Lys16(Boc)-Ile17- Ala18-OH

[0362] (Fla) (SEQ ID NO:6), or

[0363] X1-P-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)- Ser8(OtBu)-Asp9(OMpe)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OMpe)-Lys16(Boc)-Ile17- Ala18-O-2-chlorotrityl-amidomethyl resin

[0364] (Fib) (SEQ ID N0:7), orH2N-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O -19-carboxynonadecanoyl)-Ala21-Phe22-Val23-Gln24(Trt)-Trp25(Boc)-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31- Ser32(OtBu)-Ser33(OtBu)-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39(OtBu)-NH2

[0365] (F2a) (SEQ ID NO: 8), or

[0366] H2N-Gln19(Trt)-Lys20(AEEAc-AEEAc- y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-Val23-Gln24(Trt)-Trp25(Boc)-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31- Ser32(OtBu)-Ser33(OtBu)-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39(OtBu)-NH-Xanthenyl linker resin

[0367] (F2b) (SEQ ID NO: 9), or

[0368] X1-p-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)-Ser8(OtBu)-Asp9(OMpe)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OMpe)-Lys16(Boc)-Ile17-Ala18-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-OH

[0369] (F3 a) (SEQ ID NO: 10), or

[0370] X1-p-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)-Ser8(OtBu)-Asp9(OMpe)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OMpe)-Lys16(Boc)-Ile17-Ala18-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-O-2-chlorotrityl resin

[0371] (F3b) (SEQ ID NO: 11), or

[0372] X1-p-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)-Ser8(OtBu)-Asp9(OtBu)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OTBu)-Lys16(Boc)-Ile17-Ala18-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-OH

[0373] (F3c) (SEQ ID NO: 12), or

[0374] X1-p-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)-Ser8(OtBu)-Asp9(OtBu)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OtBu)-Lys16(Boc)-Ile17-Ala18-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-O-2-chlorotrityl resin

[0375] (F3d) (SEQ ID NO: 13), or

[0376] H2N-Val23-Gln24(Trt)-Trp25(Boc)-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31-Ser32(OtBu)-Ser33(OtBu)-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39(OtBu)-NH2(F4a) (SEQ ID NO: 14), or

[0377] H2N-Val23-Gln24(Trt)-Trp25(Boc)-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31-Ser32(OtBu)- Ser33(OtBu)-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39(OtBu)- NH- Xanthenyl linker resin

[0378] (F4b) (SEQ ID NO: 15).

[0379] In one particular aspect, the invention relates to the following functionalized peptide fragments:

[0380] X1-p-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)- Ser8(OtBu)-Asp9(OMpe)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OMpe)-Lys16(Boc)-Ile17- Ala18-OH

[0381] (Fla) (SEQ ID NO: 6), or

[0382] X1-p-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)- Ser8(OtBu)-Asp9(OMpe)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OMpe)-Lys16(Boc)-Ile17- Ala18-O-2-chlorotrityl-amidomethyl resin

[0383] (Fib) (SEQ ID NO:7).

[0384] In another particular aspect, the invention relates to the following functionalized peptide fragments:

[0385] X1-p-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)-Ser8(OtBu)-Asp9(OMpe)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OMpe)-Lys16(Boc)-Ile17-Ala18-Gln19(Trt)-Lys20(AEEAc-AEEAc-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-OH

[0386] (F3a) (SEQ ID NO: 10), or

[0387] X1-p-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)-Ser8(OtBu)-Asp9(OMpe)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OMpe)-Lys16(Boc)-Ile17-Ala18-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-O-2-chlorotrityl resin

[0388] (F3b) (SEQ ID NO: 11).

[0389] In another particular aspect, the invention relates to the following functionalized peptide fragments:X1-P-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)-Ser8(OtBu)-Asp9(OtBu)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OTBu)-Lys16(Boc)-Ile17-Ala18-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-OH

[0390] (F3c) (SEQ ID NO: 12), or

[0391] X1-P-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)-Ser8(OtBu)-Asp9(OtBu)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OtBu)-Lys16(Boc)-Ile17-Ala18-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-O 2-chlorotrityl resin

[0392] (F3d) (SEQ ID NO: 13).

[0393] In yet another particular aspect, the invention relates to the following functionalized peptide fragments:

[0394] H2N-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O -19-carboxynonadecanoyl)-Ala21-Phe22-Val23-Gln24(Trt)-Trp25(Boc)-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31- Ser32(OtBu)-Ser33(OtBu)-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39(OtBu)-NH2

[0395] (F2a) (SEQ ID NO: 8), or

[0396] H2N-Gln19(Trt)-Lys20(AEEAc-AEEAc- y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-Val23-Gln24(Trt)-Trp25(Boc)-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31- Ser32(OtBu)-Ser33(OtBu)-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39(OtBu)-NH-Xanthenyl linker resin

[0397] (F2b) (SEQ ID NO:9).

[0398] In a further aspect, the invention relates to the following functionalized peptide fragments:

[0399] H2N-Val23-Gln24(Trt)-Trp25(Boc)-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31-Ser32(OtBu)-Ser33(OtBu)-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39(OtBu)-NH2

[0400] (F4a) (SEQ ID NO: 14), or

[0401] H2N-Val23-Gln24(Trt)-Trp25(Boc)-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31-Ser32(OtBu)- Ser33(OtBu)-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39(OtBu)- NH- Xanthenyl linker resin

[0402] (F4b) (SEQ ID NO: 15).EXAMPLES

[0403] Abbreviations:

[0404] Boc / -biitoxy carbonyl

[0405] Bsmoc 1, 1 -dioxobenzo[b]thiophene-2- ylmethyloxy carbonyl

[0406] DIC A, A-diisopropylcarbodiimide

[0407] DIPEA diisopropylethylamine

[0408] DMF A, A-dimethylformamide

[0409] EtOAc ethyl acetate

[0410] Fmoc 9-fluorenylmethoxy carbonyl

[0411] IPE diisopropylether

[0412] ivDde 1 -(4, 4-dimethyl-2,6-di oxocyclohex- 1 -ylidene)- 3 -methylbutyl

[0413] MTBE methyl tert. -butyl ether

[0414] Mpe 3-methyl-pentyl

[0415] OxymaPure ethyl 2-cyano-2-(hydroxyimino)acetate

[0416] 2-PrOH 2-propanol

[0417] PyOxim l-cyano-2-ethoxy-2-oxoethylideneaminooxy- tris-pyrrolidino-phosphonium hexafluorophosphate

[0418] tBu tert. -butyl

[0419] sc side chain

[0420] TFA trifluoroacetic acidTIS triisopropylsilane Trt trityl1. Fragment Approach Routes

[0421] Route 1

[0422] HOPO, DIC, DIPEA - / °

[0423] XM-Ser39CH2CI2\ NH2sidechain sidechain Fl F2 Route 2

[0424] O HOPO, DIC, DIPEA or PyOxim o Vai23- / / -Ser39)— - ► f X1- / / -Ser39l—

[0425]

[0426] NH2CH2CI2 NH2sidechain sidechain

[0427]

[0428] F3

[0429] Fragments Fl, F2, F3 and F4 are functionalized peptide fragments, meaning that functional groups of respective amino acids are protected with suitable protecting groups.

[0430] 2. Solid Phase Peptide Synthesis (SPPS) of Fragments

[0431] SPPS was performed using fully automated peptide synthesizers (fragments H-Val23- / / -Ser39-NH-resin, XJ- / / -Ala18-resin and X1- / / -Lys20(sc)- / / -Phe22-resin) or carried out manually (elongation to fragment H-Gln19-Lys20(sc)- / / -Ser39-NH-resin). In general, coupling reactions were performed using Fmoc AA derivatives (default: 2.0 equiv) as building blocks as well as DIC (3.9 equiv) and OxymaPure (3.1 equiv) as coupling reagent / additive and DMF as solvent. Fmoc deprotection was typically performed by applying a solution of 20% (v / v) piperidine in DMF. DMF and 2-PrOH were used as solvents for washing steps. After each coupling, a capping step was performed routinely.

[0432] 2.1 SPPS of Fragment H-Val23- / / -Ser39-NH-resin (Fragment F4b)

[0433] 2.1.1 Process alternative A

[0434] The reaction scheme is shown in FIG.la.

[0435] Preparation of the ResinXanthenyl linker resin (145 g, loading 0.83 mmol / g, 120 mmol) was charged into a fully automated 20 L SPPS reactor. The resin was twice swelled with DMF (10 mL / g resin) and stirred for 15 min at ambient temperature. The reactor was then drained.

[0436] General Synthetic Procedure

[0437] Washing steps were designed to remove remaining deprotection solution, coupling / capping reagents and additives between process steps. Before each wash, the reactor was completely drained (i.e., until the flow into the waste accumulation vessel had ceased). The wash solvent was added to the reactor and the mixture was stirred for 3 min (starting after solvent addition is complete and stirring is started). The stirrer was then stopped and the reactor was completely drained.

[0438] All Fmoc deprotections were performed by stirring the resin with piperidine / DMF (20% v / v). In all cycles, a single deprotection treatment was performed. Stirring times with piperidine / DMF were 15 minutes in cycles 1-4 and 7-9; 20 minutes in cycles 12-14; 30 minutes in cycles 5, 6, 10 and 11. After Fmoc removal, the resin was washed with DMF and 2-PrOH, followed by DMF washes.

[0439] For all couplings, a DIC / OxymaPure procedure was used. The mixture of protected amino acid or building block, OxymaPure and DIC in DMF was stirred at ambient temperature for 5 min to pre-activate the amino acid.

[0440] Once the pre-activation was complete, the amino acid solution was added to the resin. The reaction mixture was then stirred. The reaction time for the coupling was 1.5-2 h.

[0441] Capping was performed using AC2O, 2,4,6-collidine and OxymaPure in DMF for approximately 10 minutes, followed by washing with DMF.

[0442] After completion of the solid phase synthesis, the resin was washed several times with DMF and 2-PrOH before discharging. The resin was dried under reduced pressure for 48 h.

[0443] Synthetic Procedure

[0444] The peptide was built using the general conditions for each amino acid coupling and deprotection outlined in Table 1.

[0445] The on-resin yield was 79.5%.

[0446] Table la: Conditions used for the synthesis of fragment H-Val23- / / -Ser39-NH-resin (F4b).Entry Condition / Parameter 120 mmol Build 1 Initial Xanthenyl linker resin loading 0.83 mmol / g

[0447] 2 Amount of solvent / reagent mixture for all steps 10 mL / g resin

[0448] 3 Pre-activation time for all couplings 5 min

[0449] 4 Reagents used for coupling 1-14 2.0 equiv Fmoc-AA-OH or in cycles building block

[0450] 3.1 equiv Oxyma Pure 3.9 equiv DIC

[0451] DMF solvent

[0452] 5 Resin bound drying temperature RT

[0453] 6 Resin bound drying vacuum conditions ~5 mbar

[0454] 7 Resin bound drying duration 48 h

[0455]

[0456] The detailed coupling sequence and step conditions in the various cycles are listed in Table 2.

[0457] Table 2: Detailed conditions for the synthesis of fragment H-Val23- / / -Ser39-NH-resin (F4b).

[0458] AA# Cycle # Amino Acid / Building Number and PostCoupling Block Duration of deprotection / Stir Deprotection washes Time [h] Treatments

[0459] — — Xanthenyl linker resin — 0.25 (swell) 39 1 Fmoc-L-S er(OtBu)-OH 1 x 15 min DMF / 2- 2

[0460] PrOH, 2 x

[0461] DMF

[0462] 38-37 2 Fmoc-L-Pro-L-Pro-OH 1 x 15 min DMF / 2- 1.5

[0463] PrOH, 2 x

[0464] DMF

[0465] 36-35 3 Fmoc-L-Ala-L-Pro-OH 1 x 15 min DMF / 2- 1.5

[0466] PrOH, 2 x

[0467] DMF

[0468]

[0469] AA # Cycle # Amino Acid / Building Number and PostCoupling Block Duration of deprotection / Stir Deprotection washes Time [h] Treatments

[0470] 34 4 Fmoc-Gly-OH 1 x 15 min DMF / 2- 1.5

[0471] PrOH, 2 x

[0472] DMF

[0473] 33 5 Fmoc-L-S er(OtBu)-OH 1 x 30 min DMF / 2- 1.5

[0474] PrOH, 2 x

[0475] DMF

[0476] 32 6 Fmoc-L-S er(OtBu)-OH 1 x 30 min DMF / 2- 1.5

[0477] PrOH, 2 x

[0478] DMF

[0479] 31 7 Fmoc-L-Pro-OH H2O 1 x 15 min DMF / 2- 1.5

[0480] PrOH, 2 x

[0481] DMF

[0482] 30-29 8 Fmoc-Gly-Gly-OH 1 x 15 min DMF / 2- 1.5

[0483] PrOH, 4 x

[0484] DMF

[0485] 28 9 Fmoc-L-Ala-OH H2O 1 x 15 min DMF / 2- 1.5

[0486] PrOH, 4 x

[0487] DMF

[0488] 27 10 Fmoc-L-Ile-OH 1 x 30 min DMF / 2- 1.5

[0489] PrOH, 4 x

[0490] DMF

[0491] 26 11 Fmoc-L-Leu-OH 1 x 30 min DMF / 2- 1.5

[0492] PrOH, 4 x

[0493] DMF

[0494] 25 12 Fmoc-L-Trp(Boc)-OH 1 x 20 min DMF / 2- 1.5

[0495] PrOH, 4 x

[0496] DMF

[0497] 24 13 Fmoc-L-Gln(Trt)-OH 1 x 20 min DMF / 2- 2

[0498] PrOH, 4 x

[0499] DMF

[0500] 23 14 Fmoc-L-Val-OH 1 x 20 min DMF / 2- 2

[0501] PrOH, 4 x

[0502] DMF

[0503]

[0504] AA# Cycle # Amino Acid / Building Number and PostCoupling Block Duration of deprotection / Stir Deprotection washes Time [h] Treatments

[0505] — — Fmoc deprotection 1 x 20 min DMF / 2- —

[0506] PrOH, 4 x

[0507] DMF

[0508] — — Final washes DMF / 2-PrOH / DMF / 2-PrOH / DMF / 2- PrOH / 3 x 2-PrOH

[0509]

[0510] 2.1.2 Process alternative B

[0511] The reaction scheme is shown in FIG.lb.

[0512] Preparation of the Resin

[0513] Xanthenyl linker resin (20 g, loading 0.82 mmol / g, 16.4 mmol) was charged into an SPPS reactor. The resin was swelled with DMF (8 mL / g resin) and stirred for 30 min at ambient temperature. The reactor was then drained.

[0514] General Synthetic Procedure

[0515] Washing steps were designed to remove remaining deprotection solution, coupling reagents and additives between process steps. Before each wash, the reactor was completely drained (i.e., until the flow into the waste accumulation vessel has ceased). The wash solvent was added to the reactor and the mixture was stirred for the indicated time (starting after solvent addition is complete and stirring is started). The stirrer was then stopped, and the reactor was completely drained.

[0516] Fmoc deprotections were performed by stirring the resin with piperidine / DMF (20% v / v). In cycles 3, 4 and 6-8, Oxyma Pure (2%) was used as an additive. In cycles 1-8 and 15, two treatments were performed for deprotection and in cycles 9-14 and 16, one treatment was performed. Stirring times with piperidine / DMF were 20 min in cycles 1-8, 15 and 16 and 30 min in cycles 9-14. After Fmoc removal, the resin was washed repeatedly with the indicated solvents.For all couplings, a DIC / Oxyma Pure procedure was used. The mixture of protected amino acid or building block, Oxyma Pure and DIC in DMF was stirred at ambient temperature for 20 min in cycles 1-8 and for 5 min in cycles 9-15 to pre-activate the amino acid.

[0517] After this time, the amino acid solution was added to the resin. The reaction mixture was then stirred for 2-4 h. After coupling, the reactor was drained and the resin was washed with DMF.

[0518] After completion of the solid phase synthesis, the resin was washed several times with DMF and then sequentially with CH2Cl2, 2-PrOH and MTBE before discharging. The resin was dried under reduced pressure at 35 °C for 16 h.

[0519] Synthetic Procedure

[0520] The synthesis was carried out on 16 mmol scale, resulting in the isolation of fragment H-Val23- / / -Ser39-NH-resin (51.8 g, purity 94.7 area%).

[0521] Table lb. Conditions used for the SPPS build of fragment H-Val23- / / -Ser39-NH-resin (F4b) on 16.4 mmol scale

[0522] Initial Resin Swelling

[0523] DMF

[0524] Xan thenyl linker resin

[0525] 20.0 g 1 x 10 vol

[0526] 30 min per swell

[0527] 0.82 mmol / g

[0528] 25 °C

[0529] Cycle Amino De-Fmoc Wash after Activation Coupling Wash after acids De-Fmoc condition Coupling Fmoc-L- 20%

[0530] 1 Ser(tBu)- pip / DMF

[0531] OH 2 x 6.5 vol.

[0532] 20 min per

[0533] Fmoc-L- cycle

[0534] 2 Pro- 25 °C

[0535] OH-H2O 2.0 equiv Fmoc- Fmoc-L- 20% DMF AA DMF

[0536] 3 Pro-Pro- pip / DMF 6 x 6.5 vol. 2.0 equiv Oxyma 2 h

[0537] 5 x 6.5 vol. OH with 2% 3 min per 2.2 equiv DIC 25 °C

[0538] 3 min per cycle Oxyma cycle 5 vol. DMF

[0539] 25 °C Fmoc-L- 2 x 6.5 vol. 25 °C 20 min

[0540] 4 Ala- 20 min per 25 °C

[0541] OH-H2O cycle

[0542] 25 °C

[0543] 20%

[0544] Fmoc- pip / DMF

[0545] 5 2 x 6.5 vol.

[0546] Gly-OH

[0547] 20 min per

[0548]

[0549] cycle25 °C

[0550] Fmoc-L- 6 Ser(tBu)- 20%

[0551] OH pip / DMF

[0552] with 2%

[0553] Fmoc-L- Oxyma

[0554] 7 Ser(tBu)- 2 x 6.5 vol.

[0555] OH

[0556] 20 min per

[0557] Fmoc-L- cycle

[0558] 8 Pro- 25 °C

[0559] OH-H2O

[0560] Fmoc- 9 Gly-Gly- OH

[0561] Fmoc-L- 10 Ala- OH-H2O 20%

[0562] Fmoc-L- 11 pip / DMF

[0563] Ile-OH 1 x 10 vol. DMF

[0564] 2.0 equiv Fmoc

[0565] Fmoc-L- 30 min per 1 x 10 vol. - 12

[0566] Leu-OH cycle 3 mm, 25 °C, AA

[0567] t 3.1 equiv Oxy ma

[0568] Fmoc-L- 25 °C hen

[0569] 3.9 equiv DIC

[0570] 13 Trp(Boc)- 2-PrOH 10 vol. DMF

[0571] OH 1 x 10 vol. 5 min

[0572] Fmoc-L- 3 mm, 25 °C, 25 °C 3 h

[0573] 14 Gln(Trt)- then 25°C

[0574] OH

[0575] 20% DMF

[0576] pip / DMF 4 x 10 vol.

[0577] Fmoc-L- 2 x 10 vol. 4 h

[0578] 15 3 min per

[0579] Val-OH 20 min per cycle, 25 °C 25 °C

[0580] cycle

[0581] 25 °C

[0582] 20%

[0583] pip / DMF

[0584] 1 x 10 vol.

[0585] 16 N / A 20 min per N / A N / A N / A

[0586] cycle

[0587]

[0588] 25 °C

[0589] 2.2 SPPS of Fragment H-Gln19-Lys20(sc)- / / -Ser39-NH-resin (Fragment F2b)

[0590] The reaction scheme is shown in FIG.2.

[0591] General Synthetic Procedure

[0592] The synthesis was carried out starting from fragment H-Val23- / / -Ser39-NH-resin (60 mmol). After manual coupling of Fmoc-Phe-OH, Fmoc-Ala-OH and ivDde-Lys(Fmoc)-OH, the batch was split in two portions. One portion (30 mmol) was set aside, the other portion (30 mmol) was then subjected to Fmoc deprotection, followed by coupling of the sidechain to the s-amine of the lysine residue as a single building block. Afterwards, the ivDde group wascleaved with hydrazine hydrate and the backbone construction was continued using Fmoc-Gln(Trt)-OH.

[0593] Washing steps were designed to remove remaining deprotection solution, coupling / capping reagents, and additives between process steps. Before each wash, the reactor was completely drained (i.e., until the flow into the waste accumulation vessel had ceased). The wash solvent was added to the reactor and the mixture was stirred for 3 min (starting after solvent addition is complete and stirring is started). The stirrer was then stopped and the reactor was drained completely.

[0594] All Fmoc deprotections were performed by stirring the resin with piperidine / DMF (20% v / v). IvDde deprotection was performed by stirring the resin with hydrazine / DMF (10% v / v). In all cycles, a single deprotection treatment was performed, except in cycle 4 (3 treatments).

[0595] Stirring times with piperidine(or hydrazine) / DMF were 10 minutes in cycle 4; 20 minutes in cycle 1-3 and 5. After Fmoc removal, the resin was washed with DMF and 2-PrOH, followed by DMF washes.

[0596] For all couplings, a DIC / OxymaPure procedure was used. The mixture of protected amino acid or building block, OxymaPure and DIC in DMF was stirred at ambient temperature for 5 min to pre-activate the amino acid.

[0597] Once the pre-activation was complete, the amino acid solution was added to the resin. The reaction mixture was then stirred. The reaction time for the coupling was 1.5-24 h.

[0598] Capping was performed using AC2O, 2,4,6-collidine and OxymaPure in DMF for approximately 10 minutes, followed by washing with DMF.

[0599] After completion of the solid phase synthesis, the resin was washed several times with DMF and 2-PrOH before discharging. The resin was dried under reduced pressure for 48 h.

[0600] Synthetic Procedure

[0601] The peptide was built using the general conditions for each amino acid coupling and deprotection outlined in Table 3.

[0602] The on-resin yield was 88.6%.Table 3: Conditions used for the synthesis of fragment H-Gln19-Lys20(sc)- / / -Ser39-NH-resin (F2b).

[0603] Entry Condition / Parameter 30 mmol Build

[0604] 1 Starting material H-Val23- / / -Ser39-NH-resin 2 Amount of solvent / reagent mixture for all steps 10 mL / g resin

[0605] 3 Pre-activation time for all couplings 5 min

[0606] 4 Reagents used for coupling 1-5 2.0 equiv Fmoc-AA-OH or in cycles building block

[0607] 3.1 equiv Oxyma Pure 3.9 equiv DIC

[0608] DMF solvent

[0609] 5 Resin bound drying temperature RT

[0610] 6 Resin bound drying vacuum conditions ~5 mbar

[0611] 7 Resin bound drying duration 48 h

[0612]

[0613] The detailed coupling sequence and step conditions in the various cycles are listed in Table 4. Table 4: Detailed conditions for the synthesis of fragment H-Gln19-Lys20(sc)- / / -Ser39-NH-resin (F2b)

[0614] AA# Cycle # Amino Acid / Building Number and PostCoupling Block Duration of deprotection / Stir Deprotection washes Time [h] Treatments

[0615] 0.25 — — Xanthenyl linker resin —

[0616] (swell) DMF / 2- 39 1 Fmoc-L-Ser(OtBu)-OH 1 x 15 min PrOH, 2 x 2

[0617] DMF DMF / 2- 38-37 2 Fmoc-L-Pro-L-Pro-OH 1 x 15 min PrOH, 2 x 1.5

[0618] DMF

[0619]

[0620] AA # Cycle # Amino Acid / Building Number and PostCoupling Block Duration of deprotection / Stir Deprotection washes Time [h] Treatments

[0621] DMF / 2- 36-35 3 Fmoc-L-Ala-L-Pro-OH 1 x 15 min PrOH, 2 x 1.5

[0622] DMF DMF / 2- 34 4 Fmoc-Gly-OH 1 x 15 min PrOH, 2 x 1.5

[0623] DMF DMF / 2- 33 5 Fmoc-L-Ser(OtBu)-OH 1 x 30 min PrOH, 2 x 1.5

[0624] DMF DMF / 2- 32 6 Fmoc-L-Ser(OtBu)-OH 1 x 30 min PrOH, 2 x 1.5

[0625] DMF DMF / 2- 31 7 Fmoc-L-Pro-OH H2O 1 x 15 min PrOH, 2 x 1.5

[0626] DMF DMF / 2- 30-29 8 Fmoc-Gly-Gly-OH 1 x 15 min PrOH, 4 x 1.5

[0627] DMF DMF / 2- 28 9 Fmoc-L-Ala-OH H2O 1 x 15 min PrOH, 4 x 1.5

[0628] DMF DMF / 2- 27 10 Fmoc-L-Ile-OH 1 x 30 min PrOH, 4 x 1.5

[0629] DMF DMF / 2- 26 11 Fmoc-L-Leu-OH 1 x 30 min PrOH, 4 x 1.5

[0630] DMF DMF / 2- 25 12 Fmoc-L-Trp(Boc)-OH 1 x 20 min PrOH, 4 x 1.5

[0631] DMF DMF / 2- 24 13 Fmoc-L-Gln(Trt)-OH 1 x 20 min PrOH, 4 x 2

[0632] DMF

[0633]

[0634] AA# Cycle # Amino Acid / Building Number and PostCoupling Block Duration of deprotection / Stir Deprotection washes Time [h] Treatments

[0635] DMF / 2- 23 14 Fmoc-L-Val-OH 1 x 20 min PrOH, 4 x 2

[0636] DMF

[0637] 22 1 Fmoc-L-Phe-OH 1 x 20 min DMF / 2- 3

[0638] PrOH, 4 x

[0639] DMF

[0640] 21 2 Fmoc-L-Ala-OH H2O 1 x 20 min DMF / 2- 1.5

[0641] PrOH, 4 x

[0642] DMF

[0643] 20 3 ivDde-Lys(Fmoc)-OH 1 x 20 min DMF / 2- 2 x 24 PrOH, 6 x

[0644] DMF

[0645] side4 19-carboxynonadecanoyl- 1 x 20 min DMF / 2- 1 x 6, 1 x chain Glu(AEEAc-AEEAc-OH)- PrOH, 6 x 20

[0646] OtBu DMF

[0647] 19 5 Fmoc-L-Gln(Trt)-OH 3 x 10 min DMF / 2- 6

[0648] (with PrOH, 6 x H2NNH2) DMF

[0649] — — Fmoc deprotection 1 x 20 min DMF / 2- —

[0650] PrOH, 6 x

[0651] DMF

[0652] — — Final washes DMF / 2-PrOH / DMF / 2-PrOH / DMF / 2- PrOH / 3 x 2-PrOH

[0653]

[0654] 2.3 SPPS of Fragment X1- / / -Ala18-resin (Fragment Fib)

[0655] The reaction scheme is shown in FIG.3.

[0656] Preparation of the Resin

[0657] H-Ala-2-chlorotrityl-amidomethyl resin (42.9 g, loading 0.70 mmol / g, 30 mmol) was charged into a fully automated 3 L SPPS reactor. The resin was swelled twice with DMF (10 mL / g resin) and stirred for 15 min at ambient temperature. The reactor was then drained.General Synthetic Procedure

[0658] Washing steps were designed to remove remaining deprotection solution, coupling / capping reagents, and additives between process steps. Before each wash, the reactor was completely drained (i.e., until the flow into the waste accumulation vessel has stopped). The wash solvent was added to the reactor and the mixture was stirred for 3 min (starting after solvent addition is complete and stirring is started). The stirrer was then stopped and the reactor was drained completely.

[0659] All Fmoc deprotections were performed by stirring the resin with piperidine / DMF (20% v / v). In all cycles, a single deprotection treatment was performed, except in cycle 1 (2 treatments). Stirring times with piperidine / DMF were 20 minutes in cycles 2, 3, 7-14, 16 and 17; 30 minutes in cycles 1, 4-6 and 15. After Fmoc removal, the resin was washed with DMF and 2-PrOH, followed by DMF washes.

[0660] For all couplings except cycle 1, a DIC / OxymaPure procedure was used. The mixture of protected amino acid or building block, OxymaPure and DIC in DMF was stirred at ambient temperature for 5 min to pre-activate the amino acid, except for cycle 16 (1 h of preactivation). In cycle 1, TBTU / DIPEA was employed.

[0661] Once the pre-activation was complete, the amino acid solution was added to the resin. The reaction mixture was then stirred. The reaction time for the coupling was 1.5-12 h.

[0662] Recoupling was performed for cycle 6.

[0663] Capping was performed using AC2O, 2,4,6-collidine and OxymaPure in DMF for approximately 10 minutes, followed by washing with DMF.

[0664] After completion of the solid phase synthesis, the resin was washed several times with DMF and 2-PrOH before discharging. The resin was dried under reduced pressure for 48 h.

[0665] Synthetic Procedure

[0666] The peptide was built using the general conditions for each amino acid coupling and deprotection outlined in Table 5.

[0667] The on-resin yield was 121.0%.Table 5: Conditions used for the synthesis of fragment XJ- / / -Ala18-resin (Fib).

[0668] Entry Condition / Parameter 30 mmol Build

[0669] 1 Initial H-Ala-2-chlorotrityl-amidomethyl resin 0.70 mmol / g

[0670] loading

[0671] 2 Amount of solvent / reagent mixture for all steps 10 mL / g resin

[0672] 3 Pre-activation time for all couplings 5 min (1 h for cycle 16) 4 Reagents used for coupling 1 2.0 equiv Fmoc-AA-OH in cycles

[0673] 1.8 equiv TBTU

[0674] 3.0 equiv DIPEA

[0675] DMF solvent

[0676] 2-17 2.0 equiv Fmoc-AA-OH or building block

[0677] 3.1 equiv Oxyma Pure 3.9 equiv DIC

[0678] DMF solvent

[0679] 5 Resin bound drying temperature RT

[0680] 6 Resin bound drying vacuum conditions ~5 mbar

[0681] 7 Resin bound drying duration 48 h

[0682]

[0683] Table 6: Conditions used for the synthesis of fragment XJ- / / -Ala18-resin (Fib).

[0684] AA# Cycle # Amino Acid / Building Number and PostCoupling /

[0685] Block Duration of deprotection Stir Time Deprotection washes [h] Treatments

[0686] — — H-Ala-2-chlorotrityl- — 0.25 (swell) amidomethyl resin

[0687] 17 1 Fmoc-L-Ile-OH 2 x 30 min DMF / 2- 3

[0688] PrOH, 6 x

[0689] DMF

[0690]

[0691] AA# Cycle # Amino Acid / Building Number and PostCoupling / Block Duration of deprotection Stir Time Deprotection washes [h] Treatments

[0692] 16 2 Fmoc-L-Lys(Boc)-OH 1 x 20 min DMF / 2- 6

[0693] PrOH, 6 x

[0694] DMF

[0695] 15 3 Fmoc-L-Asp(OMpe)-OH 1 x 20 min DMF / 2- 6

[0696] PrOH, 6 x

[0697] DMF

[0698] 14 4 Fmoc-L-Leu-OH 1 x 30 min DMF / 2- 3

[0699] PrOH, 6 x

[0700] DMF

[0701] 13 5 Fmoc-Aib-OH 1 x 30 min DMF / 2- 6

[0702] PrOH, 6 x

[0703] DMF

[0704] 12 6 Fmoc-L-Ile-OH 1 x 30 min DMF / 2- 2x 12 PrOH, 6 x

[0705] DMF

[0706] 11 7 Fmoc-L-Ser(OtBu)-OH 1 x 20 min DMF / 2- 1.5

[0707] PrOH, 8 x

[0708] DMF

[0709] 10 8 Fmoc-L-Tyr-OH 1 x 20 min DMF / 2- 1.5

[0710] PrOH, 8 x

[0711] DMF

[0712] 9 9 Fmoc-L-Asp(OMpe)-OH 1 x 20 min DMF / 2- 1.5

[0713] PrOH, 8 x

[0714] DMF

[0715] 8 10 Fmoc-L-Ser(OtBu)-OH 1 x 20 min DMF / 2- 1.5

[0716] PrOH, 8 x

[0717] DMF

[0718] 7 11 Fmoc-L-Thr(OtBu)-OH 1 x 20 min DMF / 2- 1.5

[0719] PrOH, 8 x

[0720] DMF

[0721] 6 12 Fmoc-L-Phe-OH 1 x 20 min DMF / 2- 1.5

[0722] PrOH, 8 x

[0723] DMF

[0724]

[0725] AA# Cycle # Amino Acid / Building Number and PostCoupling / Block Duration of deprotection Stir Time Deprotection washes [h] Treatments

[0726] 5 13 Fmoc-L-Thr(OtBu)-OH 1 x 20 min DMF / 2- 1.5

[0727] PrOH, 8 x

[0728] DMF

[0729] 4 14 Fmoc-Gly-OH 1 x 20 min DMF / 2- 1.5

[0730] PrOH, 8 x

[0731] DMF

[0732] 3 15 Fmoc-L-Glu(OtBu)- 1 x 30 min DMF / 2- 1.5

[0733] OH H2O PrOH, 8 x

[0734] DMF

[0735] 2 16 Fmoc-P-Ala-OH 1 x 20 min DMF / 2- 3

[0736] PrOH, 8 x

[0737] DMF

[0738] 1 17 2-(3-cyano-5- 1 x 20 min DMF / 2- 12

[0739] fluorophenyl)-2- PrOH, 8 x methylpropanoic acid DMF

[0740] — — Final washes DMF / 2-PrOH / DMF / 2-PrOH / DMF / 2- PrOH / 3 x 2-PrOH

[0741]

[0742] 2.4 SPPS of Fragment X1- / / -Lys20(sc)- / / -Phe22-resin (Fragment F3b, F3d)

[0743] 2.4.1 Process alternative A (Fragment F3a)

[0744] The reaction scheme is shown in FIG. 4a.

[0745] Preparation of the Resin

[0746] H-Phe-2-chlorotrityl resin (19.0 g, loading 0.79 mmol / g, 15 mmol) was charged into a fully automated 2 L SPPS reactor. The resin was swelled twice with DMF (10 mL / g resin) and stirred for 15 min at ambient temperature. The reactor was then drained.General Synthetic Procedure

[0747] Washing steps were designed to remove remaining deprotection solution, coupling / capping reagents, and additives between process steps. Before each wash, the reactor was completely drained (i.e., until the flow into the waste accumulation vessel has stopped). The wash solvent was added to the reactor and the mixture was stirred for 3 min (starting after solvent addition is complete and stirring is started). The stirrer was then stopped and the reactor was drained completely.

[0748] All Fmoc deprotections were performed by stirring the resin with piperidine / DMF (20% v / v). IvDde deprotection was performed by stirring the resin with hydrazine / DMF (10% v / v). In all cycles, a single deprotection treatment was performed, except in cycle 22 (3 treatments). Stirring times with piperidine(hydrazine) / DMF were 10 minutes in cycle 22; 20 minutes in cycles 1-4, 6, 7, 11-18, 20, 21 and 23-25; 30 minutes in cycles 5, 8-10 and 19. After Fmoc removal, the resin was washed with DMF and 2-PrOH, followed by DMF washes.

[0749] For all couplings except cycle 1, a DIC / OxymaPure procedure was used. The mixture of protected amino acid or building block, OxymaPure and DIC in DMF was stirred at ambient temperature for 5 min to pre-activate the amino acid, except for cycle 20 (1 h of preactivation). In cycle 1, TBTU / DIPEA was employed.

[0750] Once the pre-activation was complete, the amino acid solution was added to the resin. The reaction mixture was then stirred. The reaction time for the coupling was 1.5-12 h.

[0751] Recoupling was performed for cycle 10.

[0752] Capping was performed using AC2O, 2,4,6-collidine and OxymaPure in DMF for approximately 10 minutes, followed by washing with DMF.

[0753] After completion of the solid phase synthesis, the resin was washed several times with DMF and 2-PrOH before discharging. The resin was dried under reduced pressure for 48 h.

[0754] Synthetic Procedure

[0755] The peptide was built using the general conditions for each amino acid coupling and deprotection outlined in Table 7.

[0756] The on-resin yield was 82.6%.Table 7a: Conditions used for the synthesis of fragment X1- / / Lys20(sc)- / / -Phe22-resin (F3b).

[0757] Entry Condition / Parameter 15 mmol Build

[0758] 1 Initial H-Phe-2-chlorotrityl resin loading 0.79 mmol / g

[0759] 2 Amount of solvent / reagent mixture for all steps 10 mL / g resin

[0760] 3 Pre-activation time for all couplings 5 min (1 h for cycle 20) 4 Reagents used for coupling 1 2.0 equiv Fmoc-AA-OH

[0761] in cycles

[0762] 1.8 equiv TBTU

[0763] 3.0 equiv DIPEA

[0764] DMF solvent

[0765] 2-25 2.0 equiv Fmoc-AA-OH or building block

[0766] 3.1 equiv Oxyma Pure

[0767] 3.9 equiv DIC

[0768] DMF solvent

[0769] 5 Resin bound drying temperature RT

[0770] 6 Resin bound drying vacuum conditions ~5 mbar

[0771] 7 Resin bound drying duration 48 h

[0772]

[0773] The detailed coupling sequence and step conditions in the various cycles are listed in Table 8.

[0774] Table 8: Conditions used for the synthesis of fragment XJ- / / -Ala18-resin (F3b).

[0775] AA# Cycle # Amino Acid / Building Number and PostCoupling /

[0776] Block Duration of deprotection Stir Time Deprotection washes [h] Treatments

[0777] — — H-Phe-2-chlorotrityl resin — 0.25 (swell) 21 1 Fmoc-L-Ala-OH H2O 1 x 20 min DMF / 2- 3

[0778] PrOH, 4 x

[0779] DMF

[0780]

[0781] AA# Cycle # Amino Acid / Building Number and PostCoupling / Block Duration of deprotection Stir Time Deprotection washes [h] Treatments

[0782] 20 2 Fmoc-Lys(ivDde)-OH 1 x 20 min DMF / 2- 6

[0783] PrOH, 6 x

[0784] DMF

[0785] 19 3 Fmoc-L-Gln(Trt)-OH 1 x 20 min DMF / 2- 6

[0786] PrOH, 6 x

[0787] DMF

[0788] 18 4 Fmoc-L-Ala-OH-H2O 1 x 20 min DMF / 2- 2

[0789] PrOH, 6 x

[0790] DMF

[0791] 17 5 Fmoc-L-Ile-OH 2x 30 min DMF / 2- 3

[0792] PrOH, 6 x

[0793] DMF

[0794] 16 6 Fmoc-L-Lys(Boc)-OH 1 x 20 min DMF / 2- 6

[0795] PrOH, 6 x

[0796] DMF

[0797] 15 7 Fmoc-L-Asp(OMpe)-OH 1 x 20 min DMF / 2- 6

[0798] PrOH, 6 x

[0799] DMF

[0800] 14 8 Fmoc-L-Leu-OH 1 x 30 min DMF / 2- 3

[0801] PrOH, 6 x

[0802] DMF

[0803] 13 9 Fmoc-Aib-OH 1 x 30 min DMF / 2- 6

[0804] PrOH, 6 x

[0805] DMF

[0806] 12 10 Fmoc-L-Ile-OH 1 x 30 min DMF / 2- 2x 12 PrOH, 6 x

[0807] DMF

[0808] 11 11 Fmoc-L-Ser(OtBu)-OH 1 x 20 min DMF / 2- 1.5

[0809] PrOH, 8 x

[0810] DMF

[0811] 10 12 Fmoc-L-Tyr-OH 1 x 20 min DMF / 2- 1.5

[0812] PrOH, 8 x

[0813] DMF

[0814]

[0815] AA# Cycle # Amino Acid / Building Number and PostCoupling / Block Duration of deprotection Stir Time Deprotection washes [h] Treatments

[0816] 9 13 Fmoc-L-Asp(OMpe)-OH 1 x 20 min DMF / 2- 1.5

[0817] PrOH, 8 x

[0818] DMF

[0819] 8 14 Fmoc-L-Ser(OtBu)-OH 1 x 20 min DMF / 2- 1.5

[0820] PrOH, 8 x

[0821] DMF

[0822] 7 15 Fmoc-L-Thr(OtBu)-OH 1 x 20 min DMF / 2- 1.5

[0823] PrOH, 8 x

[0824] DMF

[0825] 6 16 Fmoc-L-Phe-OH 1 x 20 min DMF / 2- 1.5

[0826] PrOH, 8 x

[0827] DMF

[0828] 5 17 Fmoc-L-Thr(OtBu)-OH 1 x 20 min DMF / 2- 1.5

[0829] PrOH, 8 x

[0830] DMF

[0831] 4 18 Fmoc-Gly-OH 1 x 20 min DMF / 2- 1.5

[0832] PrOH, 8 x

[0833] DMF

[0834] 3 19 Fmoc-L-Glu(OtBu)- 1 x 30 min DMF / 2- 1.5

[0835] OH H2O PrOH, 8 x

[0836] DMF

[0837] 2 20 Fmoc-P-Ala-OH 1 x 20 min DMF / 2- 2

[0838] PrOH, 8 x

[0839] DMF

[0840] 1 21 2-(3 -cy ano-5 -fluorophenyl)- 1 x 20 min DMF / 2- 6

[0841] 2-methylpropanoic acid PrOH, 8 x

[0842] DMF

[0843] 20.1 22 Fmoc-AEEAc-OH 3 x 10 min DMF / 2- 3

[0844] PrOH, 8 x

[0845] (with

[0846] DMF

[0847] H2NNH2)

[0848]

[0849] AA# Cycle # Amino Acid / Building Number and PostCoupling / Block Duration of deprotection Stir Time Deprotection washes [h] Treatments

[0850] 20.2 23 Fmoc-AEEAc-OH 1 x 20 min DMF / 2- 3

[0851] PrOH, 8 x

[0852] DMF

[0853] 20.3 24 Fmoc-Glu-OtBu 1 x 20 min DMF / 2- 6

[0854] PrOH, 8 x

[0855] DMF

[0856] 20.4 25 Eicosanedioic acid mono1 x 20 min DMF / 2- 6

[0857] tert-butyl ester PrOH, 8 x

[0858] DMF

[0859] — — Final washes DMF / 2-PrOH / DMF / 2-PrOH / DMF / 2- PrOH / 3 x 2-PrOH

[0860]

[0861] 2.4.2 Process alternative B (Fragment F3d)

[0862] The reaction scheme is shown in FIG. 4b.

[0863] Preparation of the Resin

[0864] 2-Chlorotrityl chloride resin (10.0 g, loading 1.00 mmol / g, 10.0 mmol) was charged into an SPPS reactor. The resin was swelled with CH2Cl2(8 mL / g resin) and stirred for 30 min at ambient temperature. The reactor was then drained.

[0865] General Synthetic Procedure

[0866] Washing steps were designed to remove the remaining deprotection solution, coupling / capping reagents and additives between process steps. Before each wash, the reactor was completely drained (i.e., until the flow into the waste accumulation vessel has ceased). The wash solvent was added to the reactor and the mixture was stirred for the indicated time (starting after solvent addition is complete and stirring is started). The stirrer was then stopped, and the reactor was completely drained.

[0867] Fmoc deprotections were performed by stirring the resin with piperidine / DMF (20% v / v). In all cycles, two treatments were performed for deprotection. Stirring times with piperidine / DMF were 20 minutes in all cycles. After Fmoc removal, the resin was washed with the indicated solvents.In cycle 1, the resin was loaded using Fmoc-L-Phe-OH and DIPEA with CH2Cl2as the solvent. After this first coupling, a capping with MeOH / DMF / DIPEA was performed, followed by DMF washes.

[0868] For all couplings except in cycles 1 and 2, a DIC / Oxyma Pure procedure was used. The mixture of protected amino acid or building block, Oxyma Pure and DIC in DMF was stirred at ambient temperature for 20 min to pre-activate the amino acid. In cycle 2, TBTU / DIPEA was employed.

[0869] After pre-activation, the amino acid or building block solution was added to the resin. The reaction mixture was then stirred for 2-12 h. After coupling, the reactor was drained and the resin was washed with DMF.

[0870] After completion of the solid phase synthesis, the resin was washed several times with DMF and then sequentially with CH2Cl2, 2-PrOH and MTBE before discharging. The resin was dried under reduced pressure at 35 °C for 16 h.

[0871] Synthetic Procedure

[0872] The synthesis was carried out on 10.0 mmol scale, resulting in the isolation of fragment X1- / / -Lys20(sc)- / / -Phe22-resin (41.6 g, purity 95.0 area%).

[0873] Table 7b: Conditions used for the SPPS build of fragment X1- / / -Lys20(sc)- / / -Phe22-resin on 10.0 mmol scale.

[0874] Initial Resin Swelling

[0875] 2-CTC Resin CH2CI2

[0876] 1 x 8 vol.

[0877] 10.0 g

[0878] 30 min per swell

[0879] 1.00 mmol / g

[0880] 25 °C

[0881] Wash

[0882] De- Coupling Wash after Cycle Amino acids after Activation

[0883] Fmoc condition Coupling De-Fmoc

[0884] DMF

[0885] Loading: 2.0 equiv Fmoc- 6 x 8 vol. AA-OH 2 h,

[0886] 3 min per 4.0 equiv DIPEA 25°C

[0887] cycle 8 vol. CH2CI2

[0888] Fmoc-L-Phe- 25 °C 1 N / A

[0889] OH Capping: DMF 8 Vol. 6 x 8 vol. MeOH / DMF / DIPEA N / A 3 min per (1.6 vol. / 6.4 vol. / 2.0 equiv) cycle

[0890]

[0891] 30 mm, 25°C 25 °CDMF 2.0 equiv Fmoc-AA-OH

[0892] 1 x 10 1.8 equiv TBTU,

[0893] Fmoc-L-Ala- 2 h,

[0894] OH-H2O vol. 3.0 equiv DIPEA,

[0895] 25°C

[0896] 3 min, 25 10 vol DMF,

[0897] °C, then 5 mm, 25 °C

[0898] Bsmoc- Lys(AEEAc- 2-PrOH

[0899] E5 equiv Fmoc-AA-OH,

[0900] AEEAc-y- 1 x 10

[0901] vol. E5 equiv Oxy ma, 12 h,

[0902] Glu(O-tBu)- 3 min, 25 E65 equiv DIC 25°C

[0903] 19-carboxy- 8 vol DMF, 20 mm, 25°C

[0904] nonadecanoyl- °C, then

[0905] O-tBu)-OH

[0906] Fmoc-L- DMF

[0907] Gln(Trt)-OH 5 x 10

[0908] vol.

[0909] 3 min per

[0910] Fmoc-L-Ala- cycle

[0911] OH-H2O 25 °C

[0912] DMF

[0913] 1 x 10

[0914] vol.

[0915] 3 min, 25

[0916] °C, then

[0917] 20%

[0918] 2-PrOH

[0919] pip / DMF DMF 1 x 10

[0920] 2 x 10 6 x 10 vol.

[0921] vol.

[0922] Fmoc-L-Ile- vol. 3 min per 3 min, 25

[0923] OH 20 min cycle °C, then

[0924] per cycle 25 °C 25 °C

[0925] DMF 2.0 equiv Fmoc-AA

[0926] 6 x 10 2.0 equiv Oxy ma

[0927] vol. 2.2 equiv DIC 2 h

[0928] 3 min per 6 vol. DMF 25 °C

[0929] cycle 20 min

[0930] 25 °C 25 °C

[0931] Fmoc-L- DMF

[0932] Lys(Boc)-OH 1 x 10

[0933] Fmoc-L- vol.

[0934] Asp(OtBu)- 3 min, 25

[0935] OH °C, then

[0936] Fmoc-L-Leu- OH 2-PrOH

[0937] 1 x 10

[0938] vol.

[0939] 3 min, 25

[0940] °C, then

[0941] Fmoc-Aib-OH DMF

[0942] 8 x 10

[0943] vol.

[0944] 3 min per

[0945] cycle

[0946]

[0947] 25 °CDMF 2.5 equiv Fmoc-AA

[0948] 1 x 10 2.5 equiv Oxy ma 3 h, 40 °C

[0949] Fmoc-L-Ile- vol. 2.75 equiv DIC then

[0950] 11

[0951] OH 3 min, 25 6 vol. DMF recoupling

[0952] °C, then 20 min 4 h, 40 °C

[0953] 25 °C

[0954] Fmoc-L- 2-PrOH

[0955] 12

[0956] Ser(tBu)-OH 1 x 10

[0957] Fmoc-L vol.

[0958] 13 - Tyr(tBu)-OH 3 min, 25

[0959] Fmoc-L- °C, then

[0960] 14 Asp(OtBu)- OH DMF

[0961] lO x 10

[0962] vol.

[0963] Fmoc-L- 15 3 min per

[0964] Ser(tBu)-OH cycle 2.0 equiv Fmoc-AA

[0965] 25 °C 2.0 equiv Oxy ma

[0966] Fmoc-L- 16 2.2 equiv DIC

[0967] Thr(tBu)-OH DMF 6 vol. DMF

[0968] Fmoc-L-Phe- 1 x 10 20 min

[0969] 17

[0970] OH vol. 25 °C 2 h, 25°C

[0971] 3 min, 25

[0972] Fmoc-L- 18 °C, then

[0973] Thr(tBu)-OH

[0974] 19 Fmoc-Gly-OH 2-PrOH

[0975] 1 x 10

[0976] Fmoc-L- vol.

[0977] 20 Glu(OtBu)- 3 min, 25

[0978] OH °C, then

[0979] Fmoc-f-Ala- 21

[0980] OH DMF

[0981] 12 x 10

[0982] X-OH = vol. 1.5 equiv X-OH,

[0983] 3 min per 1.5 equiv Oxyma,

[0984] 22 YJV cycle 1.65 equiv DIC

[0985] 25 °C 6 vol DMF, 20 mm, 25°C

[0986]

[0987] 3. Soft Cleavage of Functionalized Fragments

[0988] 3.1 Soft Cleavage of Functionalized Fragment H-Gln19-Lys20(sc)- / / -Ser39-NH2 (Fragment Fla)

[0989] The reaction scheme is shown in FIG. 5.

[0990] Without pre-swelling, fragment H-Gln19-Lys20(sc)- / / -Ser39-NH-resin (20 g) was treated with 5% TFA (5 mL, 65.3 mmol) in CH2Cl2(95 mL) at ambient temperature for 30 min, followed by filtration and quenching of the filtered cleavage solution with pyridine (6.3 mL, 78.2 mmol, 1.2 equiv rel. to TFA amount). In the second cleavage step, the treatment with 5%TFA (5 mL, 65.3 mmol) in CH2Cl2(95 mL) was repeated for 30 min, again followed by filtration and quenching of the filtrate with pyridine (6.3 mL, 78.2 mmol, 1.2 equiv rel. to TFA amount). The third cleavage step was carried out using 2.5% TFA (2.5 mL, 32.7 mmol) in CH2CI2 (97.5 mL) for 30 min, with the same filtration and quenching procedure using pyridine (3.2 mL, 39.1 mmol, 1.2 equiv rel. to TFA amount). Finally, the spent resin was washed with CH2CI2 (100 mL, 5 vol.) for 20 min and the wash was combined with the quenched cleavage solutions.

[0991] ^-Heptane (1200 mL) was added to the combined cleavage filtrates at 0 °C. The resulting precipitate was filtered using a 2x8 pm PTFE filter (filtration rate: 45 mL / min). Then, a desalting wash using 10 vol. / g (rel. to solid) of water for 1 h was performed, followed by filtration using a 2x7 pm PES filter (filtration rate: 33 mL / min). Functionalized Fragment H-Gln19-Lys20(sc)- / / -Ser39-NH2 (F2a, 12 g, purity 85.0 area%, peptide content 94.9%) was isolated as a solid.

[0992] LC-MS (ESI+): mass calculated for C197H289N29O40 [M+] 3701.15, found [(m+2H)2+] 1851.58.

[0993] 3.2 Soft Cleavage of Functionalized Fragment H-Val23- / / -Ser39-NH2 (Fragment F4a)

[0994] 3.2.1 Process Alternative A

[0995] The reaction scheme is shown in FIG. 6a.

[0996] Without pre-swelling, fragment H-Val23- / / -Ser39-NH-resin (20 g) was treated with 5% TFA (5 mL, 65.3 mmol) in CH2Cl2(95 mL) at ambient temperature for 30 min, followed by filtration and quenching of the filtered cleavage solution with pyridine (6.3 mL, 78.2 mmol, 1.2 equiv rel. to TFA amount). In the second cleavage step, the treatment with 5% TFA (5 mL, 65.3 mmol) in CH2Cl2(95 mL) was repeated for 30 min, again followed by filtration and quenching of the filtrate with pyridine (6.3 mL, 78.2 mmol, 1.2 equiv rel. to TFA amount). The third cleavage step was carried out using 2.5% TFA (2.5 mL, 32.7 mmol) in CH2Cl2(97.5 mL) for 30 min, with the same filtration and quenching procedure using pyridine (3.2 mL, 39.1 mmol, 1.2 equiv rel. to TFA amount). Finally, the spent resin was washed with CH2Cl2(100 mL, 5 vol.) for 20 min and the wash was combined with the quenched cleavage solutions.

[0997] ^-Heptane (1200 mL) was added to the combined cleavage filtrates at room temperature. The resulting precipitate was filtered using a 2x8 pm PTFE filter (filtration rate: 129 mL / min). Then, a de-salting wash using 10 vol. / g (rel. to solid) of water for 1 h was performed,followed by filtration using a 2 / 7 gm PES filter (filtration rate: 44 mL / min). Functionalized Fragment H-Val23- / / -Ser39-NH2 (F4a, 8.7 g, purity 94.9 area%, peptide content 89.2%) was isolated as a solid.

[0998] LC-MS (ESI+): mass calculated for C110H161N20O23 [(M+H)+] 2130.20, found 2130.21.

[0999] 3.2.2 Process Alternative B

[1000] The reaction scheme is shown in FIG. 6b.

[1001] Fragment H-Val23- / / -Ser39-resin (5.0 g) was swelled with CH2Cl2(100 mL) for 30 min at 25 °C before it was drained. Pre-cooled (10 °C) 2.5% TFA in CH2CI2 (100 mL) was added to the resin. The resulting mixture was stirred at 10 °C for 10 min. The mixture was filtered, and the filtrate was added to pre-cooled (0 °C) pyridine (13 mL). This procedure was repeated four times with four portions of 2.5% TFA in CH2CI2 (100 mL). The spent resin was then washed with CH2CI2 (50 mL) at 10 °C for 3 min and the filtrate was combined with the above filtrates. The combined filtrates were concentrated under reduced pressure at <25 °C to 100 mL and were then added to pre-cooled (0 °C) ^-heptane (300 mL) at 0 °C. The resulting solid was isolated by filtration. The filter cake was dried under reduced pressure at 35 °C for 16 h, then washed with H2O (220 mL) at 25 °C for 30 min before it was again dried under reduced pressure at 35 °C for 15 h. Fragment H-Val23- / / -Ser39-NH2 (3.83 g, purity

[1002] 95.6 area%, assay calculated by peptide content 76.5%, 97.1% yield) was isolated as a white solid.

[1003] LC-MS (ESI+): mass calculated for C110H161N20O23 [(M+H)+] 2130.2072, found 2130.2060.

[1004] 3.3 Soft Cleavage of Functionalized Fragment X1- / / -Ala18-OH (Fragment Fla)

[1005] The reaction scheme is shown in FIG. 7.

[1006] Functionalized Fragment XJ- / / -Ala18-resin (20 g) was swelled in CH2CI2 (100 mL, 5 vol.) at ambient temperature for 30 min, after which the mixture was filtered and the filtrate was discarded. The resin was treated with 1% TFA (1 mL, 13.1 mmol) in CH2Cl2(99 mL, 5 vol.) for 30 min. The cleavage solution was filtered into the quench solution, which consisted of pyridine (2.5 mL, 31.3 mmol, 1.2 equiv rel. to overall TFA amount) in water (197 mL, 10 vol.), resulting in a biphasic neutralization mixture. In the second cleavage step, the treatment with 1% TFA (1 mL, 13.1 mmol) in CH2Cl2(99 mL, 5 vol.) was repeated for another 30 min, and the resulting solution was filtered into the quench solution from the first cleavage, maintaining the biphasic mixture. Finally, the spent resin was washed with CH2CI2 (100 mL,5 vol.) for 20 min and the wash was combined with the quenched cleavage solutions. The phases were then separated, and the aqueous layer was discarded. The volume of the organic layer was subsequently reduced to one-third (100 mL) through distillation, ensuring a peptide concentration between 100-120 g / L. The peptide concentration of fragment Fla was estimated by HPLC-UV assay as ~112 g / L (96.5% net yield, purity 95.4 area%).

[1007] LC-MS (ESI+): mass calculated for C133H215FN19O32 [(M+H)+] 2609.58, found 2609.57.

[1008] 3.4 Soft Cleavage of Functionalized Fragment X1- / / -Lys20(sc)- / / -Phe22-resin (Fragment F3a, F3c)

[1009] 3.4.1 Process Alternative A (Fragment F3a)

[1010] The reaction scheme is shown in FIG. 8a.

[1011] Functionalized Fragment X1- / / -Lys20(sc)- / / -Phe22-resin (20 g) was swelled in CH2Cl2(100 mL, 5 vol.) at ambient temperature for 30 min, after which the mixture was filtered and the filtrate was discarded. The resin was treated with 1% TFA (1 mL, 13.1 mmol) in CH2CI2 (99 mL, 5 vol.) for 30 min. The cleavage solution was filtered into the quench solution, which consisted of pyridine (2.5 mL, 31.3 mmol, 1.2 equiv rel. to overall TFA amount) in water (197 mL, 10 vol.), resulting in a biphasic neutralization mixture. In the second cleavage step, the treatment with 1% TFA (1 mL, 13.1 mmol) in CH2CI2 (99 mL, 5 vol.) was repeated for another 30 min, and the resulting solution was filtered into the quench solution from the first cleavage, maintaining the biphasic mixture. Finally, the spent resin was washed with CH2CI2 (100 mL, 5 vol.) for 20 min and the wash was combined with the quenched cleavage solutions. The phases were then separated and the aqueous layer was discarded. The volume of the organic layer was subsequently reduced to one-third (100 mL) through distillation, ensuring a peptide concentration between 100-120 g / L. The peptide concentration of fragment F3a was estimated by HPLC-UV assay as -119 g / L (65.9% net yield, purity 92.5 area%).

[1012] LC-MS (ESI+): mass calculated for C220H343FN28O49 [M+] 4180.52, found 4180.50.

[1013] 3.4.1 Process Alternative B (Fragment F3c)

[1014] The reaction scheme is shown in FIG. 8b.Fragment X1- / / -Lys20(sc)- / / -Phe22-resin (20.0 g) was treated with 1% TFA in CH2CI2 (100 mL). The resulting mixture was stirred at 25 °C for 30 min. The mixture was filtered, and the filtrate was added to H2O (200 mL, containing 2.6 mL of pyridine) at 25 °C. This procedure was repeated with another portion of 1% TFA in CH2CI2 (100 mL). The spent resin was then washed with CH2CI2 (100 mL) at 25 °C for 5 min and the filtrate was combined with the above filtrates. The phases were separated and the organic phase was concentrated under reduced pressure at <25 °C to 200 mL. z-PrOAc (200 mL) was added and the resulting mixture was concentrated under reduced pressure at <25 °C to 200 mL. This procedure was repeated three times. The resulting mixture was then added to pre-cooled (0 °C) zz-heptane (2.0 L) at 0 °C. The resulting solid was isolated by filtration. The filter cake was dried under reduced pressure at 35 °C for 15 h. Fragment X1- / / -Lys20(sc)- / / -Phe22-OH (13.5 g, purity 95.5 area%, assay calculated by peptide content 90.3%, 90.0% yield) was isolated as a white solid.

[1015] LC-MS (ESI+): mass calculated for C216H335FN28O49 [M+] 4126.4634, found [(M+2H)2+] 2064.2422.

[1016] 4. Fragment Coupling and Side Chain Deprotection

[1017] 4.1 Fragment Coupling for Route 1

[1018] The reaction scheme is shown in FIG. 9.

[1019] The coupling procedure was performed in an one-pot method. Fragment H-Gln19-Lys20(sc)- / / -Ser39-NH2 (Fragment F2a, 10.7 mmol, 1.3 equiv) was added as a solid to fragment Xk / AAla18-OH (Fragment Fla, 20 g, 8.2 mmol, 1.0 equiv, 112 g / L in CH2Cl2, telescoped from the soft-cleavage step). HOPO (1.82 g, 16.4 mmol, 2.0 equiv), DIC (2.07 g, 16.4 mmol, 2.0 equiv) and DIPEA (4.24 g, 32.8 mmol, 4.0 equiv) were then added, ensuring the pH was above 8. The mixture was stirred at 22 °C until full conversion was achieved, which took up to 48 h.

[1020] For the full-cleavage, the coupling solution was added to TFA / H2O (3 vol., 95:5 v / v) and allowed to react at 22 °C for 1-3 h. Precipitation was carried out using 3 vol. of IPE in an inverse addition mode at 22 °C. The product was isolated by centrifugation (each cycle: 5-13 min, 10 °C, up to 3500 rpm) as a wet cake (69 g, purity 65.2 area%, 2.8% epimerization at Ala18). The overall yield for Route 2 was calculated to be 46.0% based on the analysis of a dried aliquot.

[1021] LC-MS (ESI+): mass calculated for C226H345FN48O67 [M+] 4822.50, found [(m+3H)3+] 1608.50.4.2 Fragment Coupling for Route 2

[1022] 4.2.1 Process alternative A

[1023] The reaction scheme is shown in FIG. 10a.

[1024] The coupling procedure was performed in a one-pot method. Fragment H-Val23- Ser39-NH2 (Fragment F4a, 5.5 mmol, 1.1 equiv) was added as a solid to fragment X1- / / -Lys20(sc)- / / -Phe22-OH (Fragment F3a, 20 g, 5.0 mmol, 1.0 equiv, 119 g / L in CH2CI2, telescoped from the soft-cleavage step). HOPO (1.11 g, 10.0 mmol, 2.0 equiv), DIC (1.26 g, 10.0 mmol, 2.0 equiv) and DIPEA (2.59 g, 20.0 mmol, 4.0 equiv) were then added, ensuring the pH was above 8. The mixture was stirred at 22 °C until full conversion was achieved, which took up to 48 h.

[1025] For the full-cleavage, the coupling solution was added to TFA / H2O (3 vol., 95:5 v / v) and allowed to react at 22 °C for 1-3 h. Precipitation was carried out using 3 vol. of IPE in an inverse addition mode at 22 °C. The product was isolated by centrifugation (each cycle: 5-13 min, 10 °C, up to 3500 rpm) as a wet cake (72 g, purity 76.6 area%, 0.8% epimerization at Phe22). The overall yield for Route 2 was calculated to be 43.1% based on the analysis of a dried aliquot.

[1026] LC-MS (ESI+): mass calculated for C226H345FN48O67 [M+] 4822.50, found [(m+3H)3+] 1608.50.

[1027] 4.2.2 Process alternative B

[1028] The reaction scheme is shown in FIG. 10b.

[1029] Fragment Coupling:

[1030] Fragment H-Val23- / / -Ser39-NH2 (26.1 g, purity 94.0 area%, peptide content 86.1%, 1.0 equiv) and fragment X1- / / -Lys20(sc)- / / -Phe22-OH (Fragment F3c), (50.0 g, purity 95.6 area%, peptide content 88.7%, 1.0 equiv) were dissolved in DMSO / MeCN (457 mL, 4:1 v / v) at 18 °C. Then PyOxim (11.2 g, 2.0 equiv) was added and the mixture was stirred until everything was dissolved. DIPEA (8.79 mL, 5.0 equiv) was then added into the reactor and the reaction mixture was stirred for 1 h at 18 °C. After completion of the reaction, CH2Cl2(1.1 L) was added into the reactor and the organic phase was washed with water (3 x 550 mL). Then the organic phase was slowly added into ^-heptane (10 L) while stirring at 25 °C. The resulting solid was isolated by filtration. The filter cake was dried under vacuum at 35 °C for 13 h,resulting in the isolation of X1- / / -Lys20(sc)- / / -Ser39-NH2 (79.1 g, purity 75.5 area%, peptide content 67.8%, 80.0% yield) as a white solid.

[1031] Global Deprotection:

[1032] The cleavage solution (608 mL, TFA / H2O / TIS = 90:5:5(v / v / v)) was charged into a first vessel and cooled to 5 °C. Then X1- / / -Lys20(sc)- / / -Ser39-NH2 (76 g) was added while stirring and the resulting mixture was stirred for 2 h at 21 °C. In a second vessel, MTBE (5 L) was pre-cooled to 0 °C. The content of the first vessel was filtered and the filtrate was slowly added to the second vessel while stirring at 0 °C. The resulting precipitate was filtered to obtain the wet cake which was washed with MTBE (3 x 700 mL). The cake was dried under vacuum at 35 °C for 16 h, resulting in the isolation of the crude API (54.7 g, purity 65.6 area%, peptide content 56.5%, 93.0% yield) as a solid.

[1033] LC-MS (ESI+): mass calculated for C226H345FN48O67 [M+] 4824.5116, found [(M+3H)3+] 1609.1789.

[1034] ***

Claims

Claims1. Process for the preparation of the peptide of formula I, or of a pharmaceutically acceptable salt or ester thereofX1-P-Ala2-Glu3-Gly4-Thr5-Phe6-Thr7-Ser8-Asp9-Tyr10-Ser11-Ile12-Aib13-Leu14- Asp15-Lys16-Ile17-Ala18-Gln19-Lys20(AEEAc-AEEAc-y-Glu-19-carboxynonadecanoyl)- Ala21-Phe22-Val23-Gln24-Trp25-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31-Ser32-Ser33-Gly34- Ala35-Pro36-Pro37-Pro38-Ser39-NH2(I)wherein X isCNandAEEAc stands for 2-(2-(2-aminoethoxy)ethoxy)acetic acid;comprisinga) coupling of a functionalized peptide fragment FlX1-P-Ala2-Glu3-Gly4-Thr5-Phe6-Thr7-Ser8-Asp9-Tyr10-Ser11-Ile12-Aib13-Leu14-Asp15-Lys16-Ile17-Ala18-OH(Fl)with a functionalized peptide fragment F2H2N-Gln19-Lys20(AEEAc-AEEAc-y-Glu-19-carboxynonadecanoyl)-Ala21-Phe22-Val23-Gln24-Trp25-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31-Ser32-Ser33-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39-NH2(F2)or of a functionalized peptide fragment F3X1-P-Ala2-Glu3-Gly4-Thr5-Phe6-Thr7-Ser8-Asp9-Tyr10-Ser11-Ile12-Aib13-Leu14-Asp15-Lys16-Ile17-Ala18-Gln19-Lys20(AEEAc-AEEAc-y-Glu-19-carboxynonadecanoyl)-Ala21-Phe22-OH(F3)with a functionalized peptide fragment F4H2N-Val23-Gln24-Trp25-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31-Ser32-Ser33-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39-NH2(F4),wherein X and AEEAc are as defined above,b) cleaving off the protecting groups,c) precipitation of the peptide of formula I and optionallyd) purification / isolation.

2. Process of claim 1, wherein the coupling is performed in the presence of a coupling agent, an organic base and an organic solvent.

3. Process of claims 1 or 2, wherein the coupling agent is selected from benzotriazol- 1-yloxytris(dimethylamino)phosphonium hexafluorophosphate (BOP), benzotriazol-1-yloxytripyrrolidinophosphonium hexafluorophosphate (PyBOP), bromotripyrrolidinophosphonium hexafluorophosphate (PyBrOP), (7-azabenzotriazol-l-yloxy)tripyrrolidinophosphonium hexafluorophosphate (PyAOP), A-[(7A-benzotriazol-l-yl)(dimethylamino)methylene]-A-methylmethanaminium tetrafluoroborate A-oxide (TBTU), 2-(7A-benzotriazole-l-yl)-l,l,3,3-tetramethylaminium hexafluorophosphate (HBTU), 1-[bis(dimethylamino)methylene]-777-l,2,3-triazolo[4,5-b]pyridinium 3-oxide hexafluorophosphate, A-[(dimethylamino)-3A-l,2,3-triazolo-[4,5-b]pyridin-l-ylmethylene]-A-methylmethanaminium hexafluorophosphate A-oxide (HATU), propanephosphonic acid anhydride (T3P), O-(2-oxo-l(277)pyridyl)-AAA', A'-tetramethyluronium tetrafluoroborate (TPTU), l-cyano-2-ethoxy-2-oxoethylidenaminooxy)dimethylamino-morpholino-carbenium hexafluorophosphate (COMU), 1 -cyano-2-ethoxy-2-oxoethylideneaminooxy-tris-pyrrolidino-phosphonium hexafluorophosphate (PyOXIM), pentafluorophenyl diphenylphosphinate (FDPP), diphenylphosphoryl azide (DPP A), 4-(4,6-dimethoxy-l,3,5-triazin-2-yl)-4-methyl-morpholinium chloride (DMTMM) or from a combination of N, A'-diisopropylcarbodiimide (DIC) with A-hydroxysuccinimide, with 4-(dimethylamino)pyridine (DMAP), with 2-hydroxypyridine-A-oxide (HOPO) or with (ethyl-cyano (hydroximino)acetate) (OxymaPure) or from a combination of l-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) with 2-hydroxypyridine-A-oxide (HOPO).

4. Process of any one of claims 1 to 3, wherein the organic base is selected from N, N-diisopropylethylamine, A-methylmorpholine (NMM), A-methylimidazole (NMI), 2-6-lutidine, 2,4,6-collidine or from triethylamine.

5. Process of any one of claims 1 to 4, wherein the organic solvent is selected from -di methyl form am ide, toluene, methylene chloride, dimethyl sulfoxide, acetonitrile or mixtures thereof.

6. Process of any one of claims 1 to 5, whereinthe functionalized peptide fragment Fl has the formula FlaX1-P-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)- Ser8(OtBu)-Asp9(OMpe)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OMpe)-Lys16(Boc)-Ile17- Ala18-OH(Fla),the functionalized peptide fragment F2 has the formula F2aH2N-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-Val23-Gln24(Trt)-Trp25(Boc)-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31- Ser32(OtBu)-Ser33(OtBu)-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39(OtBu)-NH2(F2a),the functionalized peptide fragment F3 has the formula F3aX1-P-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)-Ser8(OtBu)-Asp9(OMpe)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OMpe)-Lys16(Boc)-Ile17-Ala18-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-OH(F3a), orthe formula F3cX1-P-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)-Ser8(OtBu)-Asp9(OtBu)- Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OTBu)-Lys16(Boc)-Ile17-Ala18-Gln19(Trt)- Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-OH(F3c),and the functionalized peptide fragment F4 has the formula F4aH2N-Val23-Gln24(Trt)-Trp25(Boc)-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31-Ser32(OtBu)- Ser33(OtBu)-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39(OtBu)-NH2(F4a),wherein X and AEEAc are as defined above.

7. Process of any one of claims 1 to 6, wherein the process comprises coupling the functionalized peptide fragment of formula FlaX1-P-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)- Ser8(OtBu)-Asp9(OMpe)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OMpe)-Lys16(Boc)-Ile17- Ala18-OH(Fla),with a functionalized peptide fragment of formula F2aH2N-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)- Ala21-Phe22-Val23-Gln24(Trt)-Trp25(Boc)-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31- Ser32(OtBu)-Ser33(OtBu)-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39(OtBu)-NH2(F2a),wherein X and AEEAc are as defined above.

8. Process of any one of claims 1 to 6, wherein the process comprises coupling the functionalized peptide fragment of formula F3aX1-P-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)-Ser8(OtBu)-Asp9(OMpe)- Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OMpe)-Lys16(Boc)-Ile17-Ala18-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-OH(F3a), orthe functionalized peptide fragment of formula F3cX1-P-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)-Ser8(OtBu)-Asp9(OtBu)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OTBu)-Lys16(Boc)-Ile17-Ala18-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-OH(F3c),with a functionalized peptide fragment of formula F4aH2N-Val23-Gln24(Trt)-Trp25(Boc)-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31-Ser32(OtBu)-Ser33(OtBu)-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39(OtBu)-NH2(F4a),wherein X and AEEAc are as defined above.

9. Process of any one of claims 1 to 8, wherein the cleaving off of the protecting groups is performed with a mixture of TFA and water and optionally an additional scavenger.

10. Process of any one of claims 1 to 9, wherein the peptide fragments Fl, Fla, F2, F2a, F3, F3a, F4 and F4a are prepared under conditions of solid phase peptide synthesis on a resin and thereafter cleaved form the resin.

11. Process of claim 10, wherein the solid phase peptide synthesis is an Fmoc-solid phase peptide synthesis.

12. Process of any one of claims 1 to 11, wherein the cleavage from the resin of the peptide fragments Fl, Fla, F2, F2a, F3, F3a, F3c, F4 and F4a is accomplished with a solution of 0.5% to 10% TFA in an organic solvent.

13. Process of claims 10 or 11, wherein the preparation of peptide fragment Fl or Fla comprises sequential coupling of the following functionalized building blocks on a resinAminoacid # Cycle# Building Block18 H- Al a-2 -chi orotrity 1 -resin17 1 Fmoc-L-Ile-OH16 2 Fmoc-L-Ly s(B oc)-OH15 3 Fmoc-L- Asp(OMpe)-OH14 4 Fmoc-L-Leu-OH13 5 Fmoc-Aib-OH12 6 Fmoc-L-Ile-OH11 7 Fmoc-L-S er(OtBu)-OH10 8 Fmoc-L-Tyr-OH9 9 Fmoc-L- Asp(OMpe)-OH8 10 Fmoc-L-S er(OtBu)-OH7 11 Fmoc-L-Thr(OtBu)-OH6 12 Fmoc-L-Phe-OH5 13 Fmoc-L-Thr(OtBu)-OH4 14 Fmoc-Gly-OH3 15 Fmoc-L-Glu(OtBu)-OH H2O2 16 Fmoc-|3-Ala-OF[1 17 2-(3 -cy ano-5 -fluorophenyl)-2- methylpropanoic acid14. Process of claims 10 or 11, wherein the preparation of peptide fragment F2 or F2a comprises sequential coupling of the following functionalized building blocks on a resinAminoacid # Cycle# Building BlockXanthenyl linker resin39 1 Fmoc-L-Ser(OtBu)-OH38-37 2 Fmoc-L-Pro-L-Pro-OH36-35 3 Fmoc-L-Ala-L-Pro-OH34 4 Fmoc-Gly-OH33 5 Fmoc-L-Ser(OtBu)-OH32 6 Fmoc-L-Ser(OtBu)-OH31 7 Fmoc-L-Pro-OH H2O30-29 8 Fmoc-Gly-Gly-OH28 9 Fmoc-L-Ala-OH H2O27 10 Fmoc-L-Ile-OH26 11 Fmoc-L-Leu-OH25 12 Fmoc-L-Trp(Boc)-OH24 13 Fmoc-L-Gln(Trt)-OH23 14 Fmoc-L-Val-OH22 15 Fmoc-L-Phe-OH21 16 Fmoc-L-Ala-OH H2O20 17 ivDde-Lys(Fmoc)-OHside-chain 18 tBu-O-19-carboxy-nonadecanoyl-L- Glu(AEEAc-AEEAc-OH)-OtBu19 19 Fmoc-L-Gln(Trt)-OH15. Process of claims 10 or 11, wherein the preparation of peptide fragment F3 or F3a comprises sequential coupling of the following functionalized building blocks on a resinAminoacid # Cycle# Building Block22 H-Phe-2-chlorotrityl-resin21 1 Fmoc-L-Ala-OH H2O20 2 Fmoc-Lys(ivDde)-OH19 3 Fmoc-L-Gln(Trt)-OH18 4 Fmoc-L-Ala-OH-H2O17 5 Fmoc-L-Ile-OH16 6 Fmoc-L-Ly s(B oc)-OH15 7 Fmoc-L- Asp(OMpe)-OH14 8 Fmoc-L-Leu-OH13 9 Fmoc-Aib-OH12 10 Fmoc-L-Ile-OH11 11 Fmoc-L-S er(OtBu)-OH10 12 Fmoc-L-Tyr-OH9 13 Fmoc-L- Asp(OMpe)-OH8 14 Fmoc-L-S er(OtBu)-OH7 15 Fmoc-L-Thr(OtBu)-OH6 16 Fmoc-L-Phe-OH5 17 Fmoc-L-Thr(OtBu)-OH4 18 Fmoc-Gly-OH3 19 Fmoc-L-Glu(OtBu)-OH H2O 2 20 Fmoc-P-Ala-OH1 21 2-(3 -cy ano-5 -fluorophenyl)-2- methylpropanoic acidsubsequent sequential built up of side chain on Lys2020.1 22 Fmoc-AEE Ac-OH20.2 23 Fmoc-AEE Ac-OH20.3 24 Fmoc-L-Glu-OtBu20.4 25 Eicosanedioic acid mono-te / 7-butyl esteror, alternatively,Aminoacid # Cycle# Building Block2-chlorotrityl resin22 1 Fmoc-L-Phe-OH21 2 Fmoc-L-Ala-OH H2O20 3 B smoc-Ly s( AEE Ac- AEE Ac-y- Glu(O-tBu)- 19-carboxy- nonadecanoyl-O-tBu)-OH19 4 Fmoc-L-Gln(Trt)-OH18 5 Fmoc-L-Ala-OH-H2O17 6 Fmoc-L-Ile-OH16 7 Fmoc-L-Lys(Boc)-OH15 8 Fmoc-L-Asp(OMpe)-OH14 9 Fmoc-L-Leu-OH13 10 Fmoc-Aib-OH12 11 Fmoc-L-Ile-OH11 12 Fmoc-L-Ser(OtBu)-OH10 13 Fmoc-L-Tyr-OH9 14 Fmoc-L-Asp(OMpe)-OH8 15 Fmoc-L-Ser(OtBu)-OH7 16 Fmoc-L-Thr(OtBu)-OH6 17 Fmoc-L-Phe-OH5 18 Fmoc-L-Thr(OtBu)-OH4 19 Fmoc-Gly-OH3 20 Fmoc-L-Glu(OtBu)-OH H2O2 21 Fmoc-P-Ala-OH1 22 2-(3 -cy ano-5 -fluorophenyl)-2- methylpropanoic acid16. Process of claims 10 or 11, wherein the preparation of peptide fragment F3 or F3c comprises sequential coupling of the following functionalized building blocks on a resinAminoacid # Cycle# Building Block2-chlorotrityl resin1 Fmoc-L-Phe-OH2 Fmoc-L-Ala-OH H2O3 B smoc-Ly s( AEE Ac- AEE Ac-y- Glu(O-tBu)- 19-carboxy- nonadecanoyl-O-tBu)-OH4 Fmoc-L-Gln(Trt)-OH5 Fmoc-L-Ala-OH-H2O6 Fmoc-L-Ile-OH7 Fmoc-L-Lys(Boc)-OH8 Fmoc-L-Asp(OtBu)-OH9 Fmoc-L-Leu-OH10 Fmoc-Aib-OH11 Fmoc-L-Ile-OH12 Fmoc-L-Ser(OtBu)-OH13 Fmoc-L-Tyr-OH14 Fmoc-L-Asp(OtBu)-OH15 Fmoc-L-Ser(OtBu)-OH16 Fmoc-L-Thr(OtBu)-OH17 Fmoc-L-Phe-OH18 Fmoc-L-Thr(OtBu)-OH19 Fmoc-Gly-OH20 Fmoc-L-Glu(OtBu)-OH H2O2 21 Fmoc-P-Ala-OH1 22 2-(3 -cy ano-5 -fluorophenyl)-2- methylpropanoic acid17. Process of claims 10 or 11, wherein the preparation of peptide fragment F4 or F4a comprises sequential coupling of the following functionalized building blocks on a resinAminoacid # Cycle# Building BlockXanthenyl linker resin39 1 Fmoc-L-S er(OtBu)-OH38-37 2 Fmoc-L-Pro-L-Pro-OH36-35 3 Fmoc-L-Ala-L-Pro-OH34 4 Fmoc-Gly-OH33 5 Fmoc-L-S er(OtBu)-OH32 6 Fmoc-L-S er(OtBu)-OH31 7 Fmoc-L-Pro-OH H2O30-29 8 Fmoc-Gly-Gly-OH28 9 Fmoc-L-Ala-OH H2O27 10 Fmoc-L-Ile-OH26 11 Fmoc-L-Leu-OH25 12 Fmoc-L-Trp(Boc)-OH24 13 Fmoc-L-Gln(Trt)-OH23 14 Fmoc-L-Val-OHor, alternatively,Aminoacid # Cycle# Building BlockXanthenyl linker resin39 1 Fmoc-L-Ser(OtBu)-OH38 2 Fmoc-L-Pro-OH H2O37-36 3 Fmoc-L-Pro-L-Pro-OH35 4 Fmoc-L-Ala-OH H2O34 5 Fmoc-Gly-OH33 6 Fmoc-L-Ser(OtBu)-OH32 7 Fmoc-L-Ser(OtBu)-OH31 8 Fmoc-L-Pro-OH H2O30-29 9 Fmoc-Gly-Gly-OH28 10 Fmoc-L-Ala-OH H2O27 11 Fmoc-L-Ile-OH26 12 Fmoc-L-Leu-OH25 13 Fmoc-L-Trp(Boc)-OH24 14 Fmoc-L-Gln(Trt)-OH23 15 Fmoc-L-Val-OH18. A functionalized peptide fragment of formula:X1-P-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)- Ser8(OtBu)-Asp9(OMpe)- Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OMpe)-Lys16(Boc)-Ile17- Ala18-OH(Fla), orX1-P-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)- Ser8(OtBu)-Asp9(OMpe)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OMpe)-Lys16(Boc)-Ile17- Ala18-O-2-chlorotrityl-amidomethyl resin(Fib), orX1-P-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)-Ser8(OtBu)-Asp9(OMpe)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OMpe)-Lys16(Boc)-Ile17-Ala18-Gln19(Trt)-Lys20(AEEAc-AEEAc-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-OH(F3a), orX1-P-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)-Ser8(OtBu)-Asp9(OMpe)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OMpe)-Lys16(Boc)-Ile17-Ala18-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-O-2-chlorotrityl resin(F3b), orX1-P-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)-Ser8(OtBu)-Asp9(OtBu)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OTBu)-Lys16(Boc)-Ile17-Ala18-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-OH(F3c), orX1-P-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)-Ser8(OtBu)-Asp9(OtBu)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OtBu)-Lys16(Boc)-Ile17-Ala18-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-O-2-chlorotrityl resin(F3d), orH2N-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O -19-carboxynonadecanoyl)-Ala21-Phe22-Val23-Gln24(Trt)-Trp25(Boc)-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31- Ser32(OtBu)-Ser33(OtBu)-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39(OtBu)-NH2(F2a), orH2N-Gln19(Trt)-Lys20(AEEAc-AEEAc- y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-Val23-Gln24(Trt)-Trp25(Boc)-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31- Ser32(OtBu)-Ser33(OtBu)-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39(OtBu)-NH-Xanthenyl linker resin(F2b), orH2N-Val23-Gln24(Trt)-Trp25(Boc)-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31-Ser32(OtBu)-Ser33(OtBu)-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39(OtBu)-NH2(F4a), orH2N-Val23-Gln24(Trt)-Trp25(Boc)-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31-Ser32(OtBu)- Ser33(OtBu)-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39(OtBu)- NH- Xanthenyl linker resin(F4b).

19. A functionalized peptide fragment of claim 18 of formulaX1-p-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)- Ser8(OtBu)-Asp9(OMpe)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OMpe)-Lys16(Boc)-Ile17- Ala18-OH(Fla).

20. A functionalized peptide fragment of claim 18 of formulaX1-p-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)- Ser8(OtBu)-Asp9(OMpe)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OMpe)-Lys16(Boc)-Ile17- Ala18-O-2-chlorotrityl-amidomethyl resin(Fib).

21. A functionalized peptide fragment of claim 18 of formulaX1-p-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)-Ser8(OtBu)-Asp9(OMpe)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OMpe)-Lys16(Boc)-Ile17-Ala18-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-OH(F3a), orof formulaX1-P-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)-Ser8(OtBu)-Asp9(OtBu)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OtBu)-Lys16(Boc)-Ile17-Ala18-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-OH(F3c).

22. A functionalized peptide fragment of claim 18 of formulaX1-P-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)-Ser8(OtBu)-Asp9(OMpe)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OMpe)-Lys16(Boc)-Ile17-Ala18-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-O-2-chlorotrityl resin(F3b) orof formulaX1-P-Ala2-Glu3(OtBu)-Gly4-Thr5(OtBu)-Phe6-Thr7(OtBu)-Ser8(OtBu)-Asp9(OtBu)-Tyr10-Ser11(OtBu)-Ile12-Aib13-Leu14-Asp15(OtBu)-Lys16(Boc)-Ile17-Ala18-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-O-2-chlorotrityl resin(F3d).

23. A functionalized peptide fragment of claim 18 of formulaH2N-Gln19(Trt)-Lys20(AEEAc-AEEAc-y-Glu(OtBu)-tBu-O -19-carboxynonadecanoyl)-Ala21-Phe22-Val23-Gln24(Trt)-Trp25(Boc)-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31- Ser32(OtBu)-Ser33(OtBu)-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39(OtBu)-NH2(F2a).

24. A functionalized peptide fragment of claim 18 of formulaH2N-Gln19(Trt)-Lys20(AEEAc-AEEAc- y-Glu(OtBu)-tBu-O-19-carboxynonadecanoyl)-Ala21-Phe22-Val23-Gln24(Trt)-Trp25(Boc)-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31- Ser32(OtBu)-Ser33(OtBu)-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39(OtBu)-NH-Xanthenyl linker resin(F2b).

25. A functionalized peptide fragment of claim 18 of formulaH2N-Val23-Gln24(Trt)-Trp25(Boc)-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31-Ser32(OtBu)- Ser33(OtBu)-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39(OtBu)-NH2(F4a).

26. A functionalized peptide fragment of claim 18 of formulaH2N-Val23-Gln24(Trt)-Trp25(Boc)-Leu26-Ile27-Ala28-Gly29-Gly30-Pro31-Ser32(OtBu)- Ser33(OtBu)-Gly34-Ala35-Pro36-Pro37-Pro38-Ser39(OtBu)- NH- Xanthenyl linker resin(F4b).***

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