SK280319B6 - Process for the production of peptides - Google Patents

Abstract

A process for the production of peptides of the formula (X)n - A - NH2 in which X is a natural or unnatural amino acid, azaamino acid or imino acid, n is an integer from 1 to 50, and A is an azaamino acid, and the physiologically tolerated salts thereof is described and is characterised in that a spacer is converted into a form which can be acylated, and the latter is reacted with a suitable formic acid derivative and subsequently with an appropriate amino acid hydrazide, where appropriate the protective group is converted into a protective group which is base-labile or labile to weak acids, the spacer obtained in this way is coupled to a resin, the required peptide is built up stepwise from the C-terminal end, and subsequently the peptide is cleaved off the resin and, where appropriate, converted into its physiologically tolerated salts.

Description

Technical field

The invention relates to a process for the production of peptides by solid phase synthesis, the peptides having C-terminal azaamino acids.

BACKGROUND OF THE INVENTION

A non-racemization process for the production of peptides with C-terminal azaamino acid amides by solid phase synthesis has not been described so far.

SUMMARY OF THE INVENTION

The present invention provides a process for the production of peptides of formula (I) (X) _n -A-NH ₂ (I), wherein:

X is a natural or non-natural amino acid, azaamino acid or imino acid, n an integer of 1 to 50, preferably 1 to 30, and

And the azaamino acid and their physiologically acceptable salts, which consists in converting the spacer into an acylable form, reacting it with a suitable formic acid derivative and then with the corresponding amino acid hydrazide, or converting the protecting group into a labile protecting group. with a basic medium or stable against weak acids, the spacer thus obtained is bound to the resin, the desired peptide is gradually formed from the C-terminal end, and finally the peptide is cleaved from the resin and optionally converted to its physiologically acceptable salts.

Natural or unnatural amino acids may, when optically active, be in the D- or L-form. Alpha-amino acids are preferred. Examples are:

Aad, Abu, GamaAbu, Abz, 2Abz, epsilonAca, Ah, Acp, Adpd, Ahb, Aib, betaAib, Ala, betaAla, deltaAla, Alg, AH, Ama, Amt, Ape, Apm, Apr, Arg, Asn, Asp, Asu, Aze, Bai, Bph, Can, Cit, Cys, (Cysty. Cyta, Daad, Dab, Dadd, Dap, Dapm, Dasu, Djen, Dpa, Dtc, Fel, Gin, Glu, Gly, Guv, hAla hArg, hCys, hGln, hGlu, His, hleu, hLeu, hLys, hMct, hPhe, hPro, hSer, hThr, hTrp, hTyr, Hyl, Hyp, 3Hyp, ile, Ise, Iva, Kyn, Lant, Len, Leu Min, nArg, Lsg, Lys, BetaLys, deltaLys, Met, Mim, Min, nArg, Nva, Oly, Om, Pan, Pac, Phe, Phg, Pie, Pro, deltaPro, Pse, Pya, Pyr, Pza, Qin , Ros, Sar, Sec, Sem, Ser, Thi, betaThi, Thr, Thy, Thx, Tia, Tie, Tly, Trp, Trta, Tyr, Val, Nal, Tbg, Npg, Cha, Chg, Thia Weyl, Methoden der organischen Chemie, Vol. XV / 1 and 2, Stuttgart, 1974).

Azaamino acids are derived from natural and unnatural amino acids, with the basic building block -CHR- or -CH2- being replaced by -NR- or -NH2-. For example, azaglycine, azavalin, azaleucine, azaisoleucine and azafenylalanine may be mentioned.

The term imino acids generally refers to natural or unnatural amino acids whose amino group is monosubstituted. Particularly contemplated in this context are compounds which are substituted with a C 1 -C 8 alkyl group, which may be mono- or di-unsaturated, and which may be substituted with up to three of the same or different moieties from the group consisting of mercapto, hydroxyl, C 1 -C 8 alkoxy. C 7 -C 7 carbamoyl, C 1 -C 8 alkanoyloxy, carboxy, C 1 -C 7 alkoxycarbonyl, fluoro, chloro, bromo, iodo, amino, amidino, which may optionally be substituted with one or two, or three C 1 -C 8 alkyl radicals, guanidino optionally substituted by one or two benzyloxycarbonyl radicals or one, two, three or four C 1 -C 8 alkyl radicals, C 1 -C 7 alkylamino, dialkylamino C 1 -C 7 -alkyl, C 1 -C 6 -alkoxycarbonylamino, C 7 -C 15 -alkoxycarbonyl, C 7 -C 15 -alkoxycarbonylamino, C 1 -C 4 -alkyloxy-alkoxycarbonyl-alkoxy, C 1 -C 6 alkyl, C 1 -C 6 alkylsulfinyl, C 1 -C 6 alkylthio, hydroxyamino, hydroxyimino and sulfamoyl.

Further suitable are heterocycles selected from the following group: pyrrolidine-2-carboxylic acid, piperidine-2-carboxylic acid, 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid, decahydroisoquinoline-3-carboxylic acid, octahydroindole- 2-carboxylic acid, decahydroquinoline-2-carboxylic acid, octahydrocyclopenta [b] -pyrrole-2-carboxylic acid, 2-azabicyclo [2.2.2] octane-3-carboxylic acid, 2-azabicyclo [2.2.1] heptane-3-carboxylic acid , 2-azabicyclo [3.1.0] hexane-3-carboxylic acid, 2-azaspiro [4.4] nonane-3-carboxylic acid, 2-azaspiro [4.5] decane-3-carboxylic acid, spiro (bicyclo [2.2. 1] heptane) -2,3-pyrrolidine-5-carboxylic acid, spiro (bicyclo [2.2.2] octane) -2,3-pyrrolidine-5-carboxylic acid, 2-azatricyclo [4.3.0.1 ^^] decane- 3-carboxylic acid, decahydro-cyclohepta [b] pyrrole-2-carboxylic acid, octahydrocyclopenta [c] pyrrole-2-carboxylic acid, octahydroisoindole-1-carboxylic acid, 2,3,3a, 4, 6a-hexahydrocyclopenta [b] pyrrole-2-carboxylic acid, 2,3,3a, 4,5,7a-hexahydroindole-2-carboxylic acid, tetrahydrothiazole-4-carboxylic acid, isoxazolidine-3-carboxylic acid, pyrazolidine-3- carboxylic and hydroxyproline-2-carboxylic acids, all of which may be substituted:

COT CCT CO- COco-, what-- ofL, <> - ’

SK 280319 Β6

Salts of the compounds of formula (I) are particularly pharmaceutically usable or non-toxic salts. Particularly suitable are alkali metal or alkaline earth metal salts, salts with physiologically acceptable amines such as methylamine and dimethylamine, and salts with inorganic or organic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, phosphoric acid, maleic acid, acid fumaric acid, citric acid, tartaric acid and acetic acid.

The process is preferably carried out by the compound of formula (II)

^R3 to a base or labile to weak acids or hydrogenation labile protecting group, for example a urethane protecting group (see, e.g., Hubbuch, Kontakte (Merck) 1979, no. 3, pp. 14 to 23) and

R ( ^{4) is} alkyl of 1 to 8 carbon atoms, cycloalkyl of 3 to 8 carbon atoms, aryl of 6 to 12 carbon atoms, arylalkyl of 6 to 12 carbon atoms in the aryl moiety and 1 to 8 carbon atoms in the alkyl moiety, a heteroaryl group, a C 1 -C 8 heteroarylalkyl group or a hydrogen atom, in a solvent in which compounds of formulas (III) and (IV) are soluble, such as dimethylformamide, to a compound of formula wherein γΐ, X ² , X ² , Y ⁴ and Y ³ hydrogen atom, C 1 -C 4 alkyl, C 1 -C 4 alkoxy or -O- (CH 2) _n -COOH, - (CH 2) _n - COOH or -NH-CO- (CH 2) _n -COOH, which radicals may be the same or different, but at least one of the radicals is -O- (CH 2) _n -COOH, - (CH 2) _n -COOH or -NH-CO (CH _{2) n} COOH, wherein n is an integer of 1 to 6, preferably 1 to 3 and

R * is hydrogen or an alkoxyaryl group having 1 to 6 carbon atoms in the alkoxy moiety and having 6 to 12 carbon atoms in the aryl moiety, preferably 4-methoxyphenyl, reacted with a silylating agent such as tert-butyldimethylsilyl chloride, tert-butylphenylsilyl chloride or trimethylchlorosilane, preferably trimethylchlorosilane, in a suitable solvent such as tetrahydrofuran, acetonitrile, methylene chloride, dimethylformamide or mixtures thereof, and then the silylated compound is converted with a chloroformic acid derivative, a particularly substituted ester derivative, to a compound of formula (III)

in which R, Yu X ^2, Y ^3, Y ^4, Y ³ and Y ^ above, and an aryl group having 6 to 12 carbon atoms which is substituted by electron-attracting substituents, preferably nitro or halogen, for example fluorine or chlorine , the compound of formula (111) thus obtained is reacted with an amino acid hydrazide of formula (IV)

R ³ - X - CO - NH - NH - R ⁴ (IV), in which it represents

Y a natural or unnatural amino acid or imino acid as defined,

wherein R ³ , R ⁴ and Y 4, X ² , Y ³ , Y ⁴ and Y ^{3 are} as defined above, wherein when R ³ represents a labile protecting group, preferably a benzyloxycarbonyl group, this protecting group is hydrogenated on palladium the catalyst is removed and converted to a base-labile urethane protecting group, preferably fmoc, or a weak acid labile urethane protecting group, preferably bpoc, prior to the next reaction, then the compound of formula (V) in which R *, R ^{4 have} , Y ¹ , X ² , Y ³ , Y ⁴ and Y ³ as defined above and R ³ represents a base-labile or weak acid labile urethane protecting group, with the aid of peptide chemistry, binds the common binding reagents via -O- (CH ₂ ) groups _n -COOH, - (CH ₂ ) _n -COOH or -NH-CO- (CH 2) _n -COOH per resin, the protecting group R ³ is cleaved off, successively bound natural or unnatural amino acids, imino acids or azaamino acids, tempo protected by base or weak acid labile amino acids, optionally in the form of their activated derivatives, and upon completion of the synthesis of the peptide of formula (I), are liberated from the resin by treatment with moderately strong acid, while temporarily introducing side protecting groups temporarily strings again cleave.

The compound of formula (IV) is prepared by reacting natural or unnatural amino acids and / or imino acids with the corresponding hydrazides using coupling methods common in peptide chemistry.

The alkyl group may be straight or branched. The same is true for derived radicals such as alkoxy, alkylthio, alkylamino, dialkylamino and alkanoyl. In particular, the alkyl group contains 1 to 4 carbon atoms.

The term cycloalkyl also includes alkyl-substituted radicals such as, for example, 4-methylcyclohexyl or 2,3-dimethylcyclopentyl.

The term halogen means fluorine, chlorine, bromine or iodine, in particular fluorine or chlorine.

Aryl having 6 to 12 carbon atoms is especially phenyl or naphthyl, phenyl being preferred. Heteroaryl represents a residue of a five or seven membered monocyclic or eight to ten membered bicyclic aromatic ring system which may be substituted with benzene, which may contain as heteroelements one, two or three different radicals selected from the group consisting of N, O, S, MO, SO, SO2, and may be substituted with one to six hydroxy groups or one, two or three of the same or different radicals selected from the group consisting of fluorine, chlorine, bromine, iodine, hydroxy, monohydroxyalkyl, dihydroxyalkyl or trihydroxyalkyl, in each case having 1 to 4 carbon atoms, trifluoromethyl, formyl, carboxyamide, monoalkylaminocarbonyl or dialkylaminocarbonyl of 1 to 4 carbon atoms, nitro, alkoxy of 1 to 7 carbon atoms, alkyl of 1 to 7 carbon atoms, alkoxycarbonyl (C až-C), amino, (C alky-C, alky) alkylamino, (C až-C dial dial) alkylamino, carboxy, carboxymethyloxy, (C až-C amino amino) aminoalkyl, (C až-C alky alky) alkylaminoalkyl group atoms in the alkyl moieties, dialkylaminoalkyl of 1 to 7 carbon atoms in the alkyl moieties, alkoxycarbonylethoxy of 1 to 7 carbon atoms in the alkoxy moiety, carbamoyl group, sulfamoyl group, alkoxysulfonyl group of 1 to 7 carbon atoms, alkylsulfonyl group C 1 -C 8 sulfoalkyl, C 1 -C 8 guanidinoalkyl and C 1 -C 8 alkoxycarbonyl and / or substituted once or twice with oxo. Particular mention may be made of furyl, thienyl, imidazolyl, pyrazolyl, oxazolyl, isoazolyl, thiazolyl, isothiazolyl, tetrazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyrrolidinyl, indolyl, indolyl, indolyl, indolyl, indolyl, indolyl, indolyl, indolyl, indolyl, indolyl, indolyl, indolyl, indolyl, a group, a quinolyl group, an isoquinolyl group, a quinoxalinyl group, a quinazolinyl group, a quinolinyl group, a beta-carbolinyl group, or a benzo derivative thereof.

If necessary to suppress side reactions or to synthesize special peptides, functional groups in the side chains of amino acids, azaamino acids or imino acids are additionally protected with suitable protecting groups (see, for example, TW Greene, Protective Groups in Organic Synthesis, New York, John Wiley) and Sons, 1981, Hubbuch, Contact (Merck)

1979, no. 3, p. 14-23, Bullesbach, Contact (Merck)

1980, no. 1, p. 23 to 35), using Arg (Tos), Arg (Mts), Arg (Mtr), Arg (Pmc), Asp (OBzl), Asp (OtBu), Cys (4-MeBzl), Cys ( Acm), Cys (StBu), Glu (OBzl), Glu (OtBu), His (Tos), His (Fmoc), His (Dnp), His (Trt), Lys (Boc), Met (O), Ser ( Bzl), Ser (tBu), Thr (Bzl), Thr (tBu). Furthermore, functional groups in the side chains may also be glycosylated, as described, for example, in EP-A 263 521 (IIOE 86 / F 253).

Resins used as carrier materials are commercially available or can be made, for example, alkoxybenzyl alcohol resins, aminomethyl resins or benzhydrylamino resins. Preferred are aminomethyl resins, benzhydrylamino resins (BHA) and methylbenzhydryla resins (MBHA). Saturation is determined by amino acid analysis and / or elemental analysis.

Suitable spacers are, for example, those described in Atherton, Sheppard in Perspectives in Peptide Chemistry, p. 101 to 117 (Karger, Basel 1981), EP-A 264 802 (HOE 86 / F 259), EP-A 287 882 (HOE 87 / F 101) and EP-A 322 348 (HOE 87 / F 386K), as well as derivatives derived therefrom, such as those in which the protecting group is cleaved. Preferred is 4-carboxylate propoxy-4'-methoxybenzhydrylamine and 5-carboxylateethyl-2,4-dimethoxy-4'-methoxybenzhydrylamine.

All activating agents used in peptide chemistry (see, for example, Houben-Weyl, Methoden der organischen Chemie, Band XV / 2, Stuttgart 1974), in particular carbodiimides, can be used as the coupling agent for the spacer of formula (V) and other amino acid derivatives, such as N, N'-dicyclohexylcarbodiimide, N, N'-diisopropylcarbodiimide or N-ethyl-N '- (3-dimethylaminopropyl) carbodiimide. The coupling can be carried out directly by the addition of an amino acid derivative with an activating agent and optionally with the addition of a racemization suppressant such as 4-dimethylaminopyridine, 1-hydroxybenzotriazole (HOBt) (W. Konig, R. Geiger, Chem. Ber. 103 ( 1970), 788-798) or 3-hydroxy-4-oxo-3,4-dihydrobenzotriazine (HOObt) (W. Konig, R. Geiger, Chem. Ber. 103 (1970), 2034-2040) per resin, or however, the pre-activation of the amino acid derivative separately as a symmetrical anhydride or HOBt ester or HOObt ester, respectively, can also be carried out and the solution of the activated substance in a suitable solvent is contacted with a peptide-capable resin.

The coupling or activation of the spacer of formula (V) and the amino acid derivative by means of said activating agents can be carried out in dimethylformamide or methylene chloride, or in a mixture thereof. The activated amino acid derivative is commonly used in a 1.5 to 4-fold excess. In cases where incomplete coupling occurs, the coupling reaction is repeated without unblocking the alpha-amino group of the peptide resin necessary to bind the next amino acid.

The successful course of the coupling reaction can be examined by a ninhydrin reaction, such as described in E. Kaiser et al. (Anal. Biochem. 34 (1970) 595). Synthesis can also be performed automatically, for example, using a peptide synthesizer (Peptide-Synthetizer Model 430A Applied Biosystems), using programs supplied by the instrument manufacturer or equally developed by the user. The latter are particularly useful when using Fmoc-protected amino acid derivatives.

The cleavage of the peptidamides from the resin is carried out by treatment with moderately strong acids such as trifluoroacetic acid, as is customary in peptide synthesis, with electron acceptor substances such as phenol, cresol, thiocresol, anisole, thioanisole, ethanedithiol, dimethylsulfide, ethylsulfide and ethylsulfide. which are customary for this process in solid phase synthesis, individually or in a mixture of two or more of these auxiliary agents. The trifluoroacetic acid can also be used in this case diluted with a suitable solvent, such as methylene chloride.

When the spacer is cleaved from the resin, the side chain protecting groups are simultaneously cleaved.

Purification of the crude peptides thus obtained is carried out by Sephadex chromatography, ion exchange resins or HPLC.

Preferred is a solid phase synthesis process for production

SK 280319 Β6

Ac-D-Nal (2) -p-Cl-D-Phe-D-Trp-Ser-Tyr-D-Ser (alpha-L-Rhay-Leu-Arg-Pro-Azagly-NH 3 and pGlu-His-Trp -Ser-Tvr-D-Ser (tBu) -Leu-Arg-Pro-Azagly-NH ₂ (Zoladex).

Abbreviations used: BSA bis-trimethylsilylacetamide

Cha cyclohexylalanine

Cg cyclohexylglycine

DCC dicyclohexylcarbodiimide

DIC diisopropylcarbodiimide

DMAP dimethylaminopyridine

Bpoc benzylpropoxycarbonyl

Fmoc 3-fluorenylmethoxycarbonyl

HOBt 1-hydroxybenzotriazole

HOObt 3-Hydroxy-4-oxo-3,4-dihydro-1,2,3-benzotriazine

Nal naphthylalanine

Npg neopentylglycine

Pmc 2,2,5,7,8-pentaethylchroman-6-sulfonyl

Tbg t-butylglycine

THF tetrahydrofuran

Thia 2-thienylalanine

The following examples serve to illustrate the invention in further detail without limiting it.

DETAILED DESCRIPTION OF THE INVENTION

Example 1

a) 5-Carboxylatoethyl-2,4-dimethoxy-4'-methoxybenzhydrylamine

17.5 g of 5-carboxylatoethyl-2,4-dimethoxy-4'-methoxybenzophenone oxime are dissolved in a 1: 1 mixture of ethanol and dimethylformamide and mixed with 2 ml of concentrated NH 2. After addition of the Pt / C catalyst, it is hydrogenated under normal pressure for 5 days. After completion of the reaction, the catalyst is filtered off with suction, the filtrate is concentrated and the product is precipitated with diethyl ether. It is used by itself without further purification.

b) N- (p-nitrophenyloxycarbonyl) -5-carboxylatoethyl-2,4-dimethoxy-4'-methoxybenzhydrylamine g of the compound of Example 1a) is added to 100 ml of a 4: 1 mixture of tetrahydrofuran and dimethylformamide and mixed with 2.1 equivalents of bis-trimethylsilylacetamide (BSA). The suspension became clear in a short time and the clear solution was stirred for two more hours. 3 g of nitrophenyl chloroformate are then added and the reaction mixture is stirred for an additional hour. After completion of the reaction, the solvent was removed under high vacuum. The residue is mixed with 300 ml of water and the resulting oily phase is extracted with ethyl acetate. The ethyl acetate phase is washed with 1 N potassium hydrogen sulphate solution and water. The organic phase is dried over anhydrous magnesium sulphate and evaporated to dryness. The residue (12 g) was determined by NHR, IR and MS.

The resulting N- (p-nitrophenyloxycarbonyl) -5-carboxylatoethyl-2,4-dimethoxy-4'-methoxybenzhydrylanone is then reacted with the amino acid hydrazides to give suitable substituted ankers.

c) Benzyloxycarbonyl-4-prolyl-azaglycyl- (5-carboxylatoethyl-2,4-dimethoxy-4'-methoxybenzhydryl) -amide

3.27 g of benzyloxycarbonylprolylhydrazide hydrochloride and 6.94 g of the compound of Example 1b) are dissolved in 40 ml of dimethylformamide (DMF) and mixed with 3 equivalents of N-ethylmorpholine and a catalytic amount of dimethylaminopyridine (DMAP). The reaction mixture was allowed to react for hours. After completion of the reaction, the mixture was evaporated to dryness. The residue is taken up in a mixture of ethyl acetate and butyl alcohol and the organic phase is washed with saturated sodium bicarbonate solution, 1 N potassium hydrogen sulphate solution and water. The organic phase is then dried over anhydrous magnesium sulphate and evaporated to dryness after filtration. The residue was recrystallized from pure ethyl acetate. 6.6 g of the title compound are obtained.

FAB-MS: 641 (M + Li ^&lt; ^{+ &gt;} )

IR: CO 1695 cm ^{-1 1} H-NMR (DMSO): δ = 3.7 s (6H, OCH ₃ ) ppm.

d) 9-Fluorenylmethoxycarbonyl-L-prolyl-azaglycyl- (5-carboxylatoethyl-2,4-dimethoxy-4'-methoxybenzhydryl) amide

26.5 g of the compound of Example 1c) are dissolved in 300 ml of methanol and 2 g of palladium catalyst are added. After one hour, the hydrogenation was complete. The catalyst is filtered off and the filtrate is concentrated to dryness. Without further purification, the residue (17.5 g) was taken up in a mixture of 80 ml of water and 80 ml of dioxane and treated with 8 g of sodium bicarbonate and 9-fluorenylmethoxycarbonyl-N-hydroxysuccinimide (Fmoc-CNSu). The reaction mixture was allowed to react for one day. After completion of the reaction, filter through a clarifying filter. The pH of the filtrate is adjusted to 6 with 2 N sulfuric acid and the volume is reduced to 80 ml in vacuo. The mixture is then diluted with 100 ml of water and extracted with a mixture of ethyl acetate and n-butyl alcohol (8.5: 1.5). The organic phase is washed with half-saturated sodium chloride solution and then evaporated to dryness. The residue is filtered through 500 g of silica gel with ethyl acetate. 20 g of the title compound are obtained. FAB-MS: 729 (M + Li ^&lt; ^{+ &gt;} )

IR: CO 1695 cm @ -1.

e) Binding the compound of Example 1d) to a polystyrene resin

1.0 g of aminomethyl polystyrene resin (1.07 mmol saturation) and 1.2 g of the compound of Example 1d) are suspended in 10 ml of dimethylformamide and mixed with 216 mg of 1-hydroxybenzotriazole (HOBt) and 0.75 ml of diisopropylcarbodiimide (DIC). . The reaction mixture was allowed to react overnight until the ninhydrin test showed complete reaction. The resin was filtered off and washed with dimethylformamide and methylene chloride and dried completely in vacuo. The resin saturation proline is 0.51 mmol / g.

f) Ac-D-Na (2) -p-G1-D-Phe-D-Trp-Ser-Tyr-D-Ser (alpha-L-Rha) -Leu-Arg-Pro-Azagly-NH2

The 9-fluorenylmethoxycarbonyl-N-amino protecting group of the compound of Example 1c) was cleaved with a 20% solution of piperidine in dimethylformamide (2x3 min, 2x8 mL). Then the resin is washed with N-methylpyrrolidone (5x10 ml) and the peptide is bound to the resin (785 mg of the resin of Example 1c)), cyclically performing the following steps:

- cleavage of the Fmoc-protecting group with 20% piperidine in DMP,

- washing the resin with DMP / N-methylpyrrolidone,

binding of the Fmoc-amino acid under in situ activation as HOBt-ester using diisopropylcarbodiimide as activating agent (1.5 mmol of amino acid, 2.25 mmol of HOBt, 1.6 mmol of diisopropylcarbodiimide).

If the binding was incomplete (Kaiser test), the binding step was repeated. Fmoc-D-Nal (2) -OH was used as the last amino acid. The N-terminal acetyl group is introduced by reaction with acetic anhydride.

After the solid-phase synthesis is complete, the resin is washed (DMF, CH 2 Cl 2) and dried thoroughly to give 1.35 g of substituted resin.

The dried resin was suspended at room temperature with 0.75 ml of ethanedithiol. After 15 minutes, 7.5 ml of trifluoroacetic acid is added and the suspension is stirred for 1.5 hours. After this time, the resin was filtered off and washed well with 80% trifluoroacetic acid.

The filtrate was evaporated in vacuo and taken up in 30 ml of water. The pH was adjusted to 6-7 by the addition of sodium bicarbonate and the peptide was shaken with n-pentanol (4 x 30 mL). The N-pentanol phase is evaporated, taken up in 10 ml of a mixture of methanol and water (9: 1) and mixed with 0.5 g of potassium carbonate. The reaction mixture was stirred for 30 minutes, filtered and the filtrate was concentrated. The residue is taken up in 100 ml of n-pentanol and the organic phase is washed with water. After drying over magnesium sulfate and filtration, the organic phase is evaporated. 740 mg of crude product are obtained. Chromatography on Sephex G 25 (1 M acetic acid) and silica gel yields 185 mg of the pure title compound. FAB-MS: 1531 (M + H &lt; ^{+ &gt;} ).

Claims (2)

PATENT CLAIMS A process for the production of peptides of the general formula (I) (X) _n -A-NH ₂ (I), in which: X is a natural or non-natural amino acid, azaamino acid or imino acid, n an integer of 1 to 50, preferably 1 to 30, and The azaamino acid and their physiologically acceptable salts, characterized in that the spacer is converted to an acylated form, which is reacted with a suitable formic acid derivative and then with the corresponding amino acid hydrazide, or the protecting group is converted into a base labile protecting group. or against weak acids, the spacer thus obtained is bound to the resin, the desired peptide is constructed from the C-terminal end, then the peptide is cleaved from the resin and optionally converted to its physiologically acceptable salt. A process according to claim 1, characterized in that the compound of formula (II) in which it is Y to Y ^2, Y ^3, Y ⁴ and Y ³ hydrogen, alkyl having 1 to 4 carbon atoms, alkoxy of 1 to 4 carbon atoms, or a group -O- _{(CH2) n-COOH,} - _(CH2 ) _n -COOH or -NH-CO- (CH ₂ ) _n -COOH, which radicals may be the same or different and at least one of the radicals is -O- (CH ₂ ) _n -COOH, - (CH ₂ ) _n -COOH or -NH-CO (CH ₂ ) _n -COOH and n is an integer from 1 to 6 a R * is a hydrogen atom or an alkoxyaryl group having 1 to 6 carbon atoms in the alkoxy moiety and having 6 to 12 carbon atoms in the aryl moiety, reacted with the silylating agent in a suitable solvent, and then the silylated compound is converted with the chloroformic acid derivative to III) in which R 1, Y ² , Y ² , Y ³ , Y ⁴ and Y ^{3 are} defined as ag R represents an aryl group having 6 to 12 carbon atoms which is substituted with electron-withdrawing substituents, preferably nitro or halogen, the compound of formula (III) thus obtained is reacted with an amino acid hydrazide of formula (IV) R ³ -X-CO-NH-NH-R ⁴ (IV) in which it represents X a natural or unnatural amino acid or imino acid as defined, R ^{3 is a} labile or weak acid labile, optionally hydrogenated labile protecting group, and R ^{4 is an} alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, an aryl group having 6 to 12 carbon atoms, an arylalkyl group having C 6 -C 12 aryl and C 1 -C 8 alkyl, heteroaryl, C 1 -C 8 heteroarylalkyl or hydrogen in a suitable solvent for compounds of formula (V) X-R ³ in which R ¹ , R ³ , R ⁴ and γΐ, Y ² , Y ³ , Y ⁴ and Y ^{3 are} as defined above, wherein when R ³ represents a labile protecting group, this protecting group is hydrogenated the palladium catalyst is removed and before the further reaction is converted to the base forms a labile, or to weak acid labile urethane protecting group, then the compound of formula (V), in which R, R ^4, γΐ, Y ^2, Y ^3, Y ⁴ and Y ^{3 are} as defined above and R ³ stands for bases or weak labile acids The urethane protecting group is bonded via the -O- (CH ₂ ) _n -COOH groups using coupling reagents common in peptide chemistry. - (CH ₂ ) _n -COOII or -NH-CO- (CH ₂ ) _n -COOH per resin, the protecting group R 1 is cleaved off, successively bound natural or unnatural amino acids, imino acids or azaamino acids, temporarily protected by amino-labile groups bases or weak acids, optionally in the form of their activated derivatives, and upon completion of the synthesis of the peptide of formula (I), they are liberated from the resin by treatment with moderately strong acid, and the temporarily introduced side chain protecting groups are cleaved thereafter.