CS255896B2 - Process for preparing derivatives of aminoacids - Google Patents

Abstract

Die Erfindung betrifft neue Aminosäurederivate der allgemeinen Formel sowie ihre Salze.

Gegenstand der Erfindung sind ferner Verfahren zu ihrer Herstellung, pharmazeutische Zusammensetzungen und die Anwendung als Arzneimittel.

In Formel I bedeuten:

• R, H, Acetyl, Benzoyl, Pivaloyl oder den Rest P eine der Zahlen 1 - 4; A den Rest einer der α-Aminosäuren oder
• R₂ Wasserstoff, C₁-C₄-Alkyl, gerade oder verzweigt, C₅-C₇-Cycloalkyl, wobei ein Phenylring ankondensiert sein kann, Phenyl, Phenyl-C₁-C₄-alkyl, einen Hetero-C₁-C₄- alkylrest, wobei der Heterocyclus aus einem 5- oder 6-Ring mit 1 - 2 der Heteroatome O; S oder N besteht,
• R₃ Wasserstoff, C₁-C₄-Alkyl, gerade oder verzweigt, Phenyl, Phenyl-C₁-C₄-alkyl oder einen Hetero-C₁-C₄-alkylrest, wobei der Heterocyclus aus einem 5- oder 6-Ring mit 1 - 2 der Heteroatome 0, S oder N besteht, oder
• R₂ und R₃ zusammen bilden mit dem N- und dem C-Atom einen 5-, 6- oder 7-gliedrigen Ring, der gesättigt sein oder eine Doppelbindung enthalten kann, oder einen 4-, 5-oder 6-gliedrigen Ring, der ein oder zwei weitere der Heteroatome 0, S oder N enthält;
• R₄ OH, C₁-C₄-ω-Hydroxyalkyl, C₁-C₄-Alkoxy, Phenyl-C,-C₄-alkoxy, C₁-C₄-Akylamino, (C₁-C₄)₂-Dialkylamino, eine der Gruppen oder oder eine α-Aminosäure, die peptidartig mit der CO-Gruppe des Moleküls verknüpft ist;
• R₅ C₁-C₄-Alkyl, C₁-C₃-Alkenyl, C₁-C₃-Alkinyl, gerade oder verzweigt, Hydroxy, Nitro, Amino, C₁-C₄-Alkoxy, Mercapto, C1-C,-Alkylthio, Hydroxy-C₁-C₄-alkyl, Mercapto-C₁-C₄-alkyl, F, Cl, Br, Amino-C₁-C₄-alkyl, Sulfonamido, Methylendioxy, Fluor-C,-C₄-alkyl, Chlor-C₁-C₄-alkyl, Brom-C₁-C₄-alkyl, Cyano oder Trifluormethyl;
• R₆ Wasserstoff oder Methyl;
• R₇ C₁-C₄-Alkyl, gerade oder verzweigt, wobei der Alkylrest durch F, Cl, Br, CF₃, Phenyl oder Pyridyl substituiert sein kann;
• X, Y und Z 0, S, NR_B, CR₉, CHR₉, oder mit der Maßgabe, daß nur einer der Reste X, Y und Z O, S )der und einer oder zwei der Reste X, Y und Z NR₈ bedeuten können;
• R₈ Wasserstoff oder C₁-C₄-Alkyl, gerade oder verzweigt;
• R₉ Wasserstoff, oder zusammen mit einem vicinal stehenden Rest Rg einen Phenylring oder, für m und n = 1, dessen Dihydroform mit der Doppelbindung in Konjugation zur C-terminalen Carboxygruppe und
• m und n jeweils 0, 1 oder 2, wobei die Summe aus m und n 1 oder 2 ist.

Die neuen Verbindungen besitzen eine starke Angiotensin-i-Converting-Enzym-Hemmung und sollen als Hypotensiva Verwendung finden.

Description

The invention relates to novel amino acid derivatives of the formula I

NHR

SR, (CH3).

I I

CH 2 CH-CO-NH-CH-CO-A and salts thereof, the present invention provides a process for the preparation of such compounds.

The invention further provides pharmaceutical compositions comprising the above compounds as active ingredients and their use in medicaments.

In the above general formula I

R 1 represents a hydrogen atom or an acetyl group,

R is hydrogen, acetyl or target, butoxycarbonyl, and

A is proline, 4-carboxythiazolidin-3-yl, (5-methoxy-2-oxo-)

1,3-dioxolen-4-yl) proline methyl ester, a proline O-pivaloyloxymethyl ester residue, or a 4- (pivaloxymethoxycarbonyl) thiazolidin-3-yl residue, wherein the above residues are linked via a peptide bond through a nitrogen atom.

The novel compounds generally contain several centers of asymmetry and therefore occur as diastereomers or in the form of their racemate or racemic mixtures. The invention includes both these racemic mixtures and the individual diastereomers. Preferred are those enantiomers in which the asymmetric carbon atoms have the S configuration.

The abovementioned racemates can be enriched in individual sterically uniform forms in a conventional manner, for example by fractional crystallization, chemical or biochemical resolution, or can be obtained in pure form.

The compounds of the invention exist in the form of their internal salts (betaines) and can therefore form salts with both acids and bases. Examples of inorganic bases suitable for this purpose include ammonia, alkali metal hydroxides such as sodium or potassium hydroxide, or alkaline earth metal hydroxides such as calcium or magnesium hydroxides, and suitable organic bases include N, N'-dibenzylethylenediamine or triethylamine. Examples of acids suitable for the preparation of salts include hydrohalic acids, sulfuric acid or sulfonic acids.

In accordance with the invention, the compounds of formula (I) and salts thereof are prepared by the preparation of compounds of formula (II)

NHR I Br 1 (ch ₂ ) ₄

(II)

CH-CO-NH-CH-CO-A in which

R and A are as defined above, reacted with a mercapto compound of formula III

HS - Ry in which

R1 is as defined above, whereupon the compound of formula I obtained is optionally converted into a salt.

The reaction of the intermediate bromo derivative of the formula II with the mercapto compound of the formula III is preferably carried out in ether as the reaction solvent. Reaction with thiol acetic acid affords the corresponding acetyl mercapto compound from which the acetyl group can be cleaved by treatment with a strong base.

The starting materials of the formula II are prepared from the individual amino acids by the condensation reactions customary in peptide chemistry, using activated forms of the respective acids or condensing agents. Suitable carboxyl-activating groups are residues of the acid chloride, azide, anhydride, p-nitrophenyl ester, cyanomethyl ether and the like. The condensing agent is preferably carbonyldiimidazole, dicyclohexylcarbodiimide, ethoxyacetyl, diphenylphosphoryl azide or chloroformic acid ester. The reactions are carried out at a temperature between 0 ° C and + 10 ° C. Specific preparations of the starting materials are given in the Examples.

In this case, the use of methylene chloride as solvent together with dicyclohexylcarbodiimide and triethylamine has proven advantageous.

The starting materials of the formula III are known.

The amino acid derivatives of formula I exhibit a strong and long-term blood pressure lowering effect based on the inhibition of angiotensin I converting enzyme and thereby blocking the formation of vasoconstrictor angiotensin II from angiotensin I. In addition, the compounds of the invention inhibit the kininase II enzyme responsible for degradation of bradykinin, which enzyme is considered identical to the aforementioned converting enzyme. Since bradykinin causes vascular expansion, the hypotensive effect of the novel compounds is enhanced by this complementary effect. Bradykinin-induced blood pressure lowering in normal rats is enhanced by the administration of the novel compounds. The effect of this could also be the hypotensive effect observed in untreated, genetically hypertensive rats.

In narcotized rats in which blood pressure was elevated by irttravene administration of 0.1 mg / kg of angiotensin I, intravenous administration of Ы-β * - (3-phenyl-2-S-mercaptopropanoyl) -S-lysyl] thiazolidin-4-S -carboxylic acids for a prolonged blood pressure reduction of 60%. N- [n * - (3-phenyl-2-S-mercaptopropanoyl) -S-lysyl] -S-proline shows 57% activity in this test.

N-fN ¹ * - (3-phenyl-2-S-mercaptopropanoyl) -S-lysyl] thiazolidine-4-S-carboxylic acid exhibits angiotensin I converting enzyme I inhibitory activity ΙΟ ΙΟ ΙΟ = 4.6 in vitro. 10 ~ ⁹ [mJ; IC _5O values for (3-phenyl-2-S-S-merkaptopropanoyll-lysyl] -S-proline is 2.7. 10 ⁸

См].

The IC 50 is the concentration that inhibits 50% of the angiotensin I converting enzyme [see H. S. Cheung, D. W. Cushman, Biochem. Biophys. Acta 293, 451 (1973)].

For therapeutic use, the novel compounds are mixed with conventional pharmaceutical fillers or carriers, binders, tablet disintegrants, glidants, thickeners or diluents. Suitable pharmaceutical forms are, for example, tablets, capsules, suppositories, solutions, syrups, emulsions or dispersible powders, the pharmaceutical forms which may optionally contain other known active substances, for example saluretics, diuretics and / or angihypertensive agents.

Suitable tablets may be prepared, for example, by mixing the active ingredient with known excipients such as inert diluents such as calcium carbonate, calcium phosphate or milk sugar, disintegrating agents such as corn starch or alginic acid, binders such as starch or gelatin, glidants substances such as magnesium stearate or talc, and / or depot effecting agents such as carboxypolymethylan, carboxymethylcellulose, cellulose acetate phthalate or polyvinyl acetate. The tablets may consist of several layers.

Similarly, dragees can be prepared by coating dragee cores prepared analogously to tablets using conventional agents used to coat dragee cores such as collidone or shellac, acacia, talc, titanium dioxide or sugar. In order to achieve a depot effect or to prevent the occurrence of an incompatibility, the dragee core may also consist of several layers, as well as dragee coatings may consist of several layers to achieve the depot effect. In preparing these dosage forms, the excipients mentioned above in the preparation of tablets may be used.

The active ingredient syrups may further contain a sweetening agent, such as saccharin, cyclamate, glycerin or sugar, as well as flavor enhancers, for example flavoring agents such as vanillin or orange extract. These syrups may additionally contain suspending aids or thickeners, such as sodium carboxymethylcellulose, wetting agents, for example, condensation products of meat alcohols with ethylene oxide, or preservatives, such as p-hydroxybenzoate.

Injectable solutions are prepared in conventional manner, for example, using preservatives, such as p-hydroxybenzoates, or stabilizers, such as alkali salts of ethylenediaminotetraacetic acid, and, if appropriate, to aid dissolution, and are filled into vials or ampoules.

Capsules containing one or more active compounds or combination of active compounds can be prepared by mixing the active compound with inert carriers such as milk sugar or sorbitol and filling the mixture with gelatin capsules.

The compounds of the formula I according to the invention or their salts are administered in daily doses ranging from 5 to 500 mg, preferably from 10 to 100 mg, and can be administered one to four times a day.

The invention is illustrated in more detail by the following non-limiting examples. The structure of all synthesized compounds in the examples was confirmed by NMR spectroscopy.

Example 1

N-N- (3-phenyl-2-S-acetylmercaptopropanoyl) -S-lysyl-5-proline

--COOH

10.7 g (26.7 mmol) of N- (N-t-butoxycarbonyl-S-lysyl) -S-proline tert-butyl ester and

6.11 g (26.7 mmol) of 3-phenyl-2-R-bromopropionic acid is dissolved in 270 ml of anhydrous dichloromethane and 5.5 g (26.7 mmol) of N are added under stirring at 0 ° C. , N'-dicyclohexylcarbodiimide. The reaction mixture was stirred at room temperature overnight, the precipitated urea derivative was filtered off with suction and the filtrate was evaporated in vacuo. The residue was dissolved in ethyl acetate and the insoluble material was filtered off. The organic phase is washed successively with 5% potassium hydrogen sulphate solution, sodium hydrogen carbonate solution and saturated sodium chloride solution, dried over magnesium sulphate and the ethyl acetate distilled off in vacuo. As an oily residue, 14 g (85.8% of theory) of the product formed by HNMR spectroscopy of N-fN ^ - (3-phenyl-2-R-bromopropanoyl) -N ^{'-tert-butoxycarbonyl-S-lysylJ-} S-proline.

To introduce the acetyl mercapto group, 3.48 g (45.8 mmol) of thiol acetic acid was dissolved in 120 ml of anhydrous ether and 4.62 g (45.8 mmol) of triethylamine, and at 0 [deg.] C. 14 g (22.9 g) were added to the solution. mmol) of the bromo derivative obtained above. The mixture was heated to reflux for 90 minutes, allowed to stand overnight, the precipitated triethylamine hydrobromide was filtered off with suction and the filtrate was distilled off in vacuo. 15.5 g of a brown oily material are obtained which, after chromatography on silica gel with a mixture of equal parts of ethyl acetate and n-hexane as eluent, yields 9.4 g (67.7% of theory) of tert-butyl ester. Ν ^{, ζ} - (3-phenyl-2-S-acetylmercaptopropanoyl) -N-tert-butoxycarbonyl-S-lysyl-5-proline.

To saponify the tert-butyl ester while cleaving the tert-butoxycarbonyl protecting group, 5.5 g (9.08 mmol) of the ester obtained in the previous paragraph are dissolved in 150 ml of trifluoroacetic acid and the mixture is stirred at room temperature overnight. After the trifluoroacetic acid was distilled off in vacuo, the residue was dissolved several more times in dichloromethane and evaporated. The residue was dissolved in sodium bicarbonate solution and shaken with ethyl acetate. The aqueous phase was acidified with concentrated hydrochloric acid and extracted twice with dichloromethane. The combined dichloromethane extracts were washed with water and saturated sodium chloride solution and, after drying, distilled off in vacuo. A 0.5 g residue is obtained. The aqueous phase is saturated with sodium chloride and extracted again with dichloromethane. After drying over magnesium sulfate and evaporation, an additional 3 g (together 3.5 g) of a solidified foamed product is obtained which, according to NMR spectroscopy, structurally corresponds to the title compound.

Rf = 0.22 (silica gel; butanol-acetic acid-water 3: 1: 1).

Example 2

N- (N-N- (3-phenyl-2-S-mercaptopropanoyl) -S-lysyl) -thiazolidine-4-S-carboxylic acid

3.5 g (7.6 mmol) of N- (3-phenyl-2-R-bromopropanoyl) -Nt-t-butoxycarbonyl-S-lysine and 1.4 g (7.6 mmol) of thiazolidine-methyl ester hydrochloride 4-S-carboxylic acids are dissolved in 70 ml of anhydrous dichloromethane and 769 mg (7.6 mmol) of triethylamine are added first to the solution while stirring and cooling to 0 ° C, followed by 1.6 g (7.6 mmol) η, N'-dicyclohexylcarbodiimide. The reaction mixture is stirred at room temperature for about 17 hours, then the precipitated dicyclohexylurea is filtered off with suction and the solvent is distilled off. The oily residue is dissolved in ethyl acetate, the solution is filtered again after cooling and the organic phase is washed successively with dilute potassium hydrogen sulphate solution, saturated sodium bicarbonate solution, water and saturated sodium chloride solution. After drying over magnesium sulfate, the solvent was distilled off in vacuo. 4.1 g of crude oily reaction product are obtained, which product is purified by chromatography on silica gel using equal parts of ethyl acetate and n-hexane as eluent. 2.9 g (68.8% of theory) of N- [N- (3-phenyl-2-R-bromopropanoyl) -N-tert-butoxycarbonyl-S-lysyl] thiazolidine-4-S-carboxylic acid methyl ester are obtained. in the form of a solidified foam which crystallizes from ether.

R _f = 0.43 / silica gel; ethyl acetate - n-hexane 2: 1).

To replace bromine with acetylmercapto, to a solution of 792 mg (10.4 mmol) of thiol acetic acid in 35 ml of anhydrous ether under nitrogen and with ice-cooling was slowly added 1.05 g (10.4 mmol) of triethylamine, and then dropwise added with stirring. solution of 2.9 g (5.2 mmol) of the above bromo derivative in 20 ml of ethyl acetate. The reaction mixture was refluxed for 60 minutes, cooled, filtered and washed successively with dilute potassium bisulfate solution, sodium bicarbonate solution, water and saturated sodium chloride solution. After drying over magnesium sulfate, the solvent was distilled off in vacuo and the yellowish oily residue (3.3 g) was purified by chromatography on a 100 g silica gel column eluting with ethyl acetate / n-hexane (2: 1). It is obtained

1.9 g (64.1% of theory) of pure methyl ester (3-phenyl-2-S-aceylmercaptopropanoyl)

-target. butoxycarbonyl-S-lysyl} thiazolidine-4-S-carboxylic acid as a solidified foam.

Rf = 0.36 (silica gel; ethyl acetate-n-hexane 2: 1).

For cleavage of the butoxycarbonyl protecting group, 1.9 (3,33 mmol) of the above prepared acetyl mercapto compound is stirred at room temperature with 40 ml of trifluoroacetic acid for 3 hours, then the mixture is evaporated to dryness in vacuo and the remaining traces of trifluoroacetic acid are removed successively three times. dissolved in acetone and chloroform and evaporated again. 2.7 g of (3-phenyl-N-S-acetyl-mercaptopropanoyl) -S-lysyl] thiazolidine-4-S-carboxylic acid methyl ester are obtained in the form of a viscous oil.

R _f = 0.23 (silica gel, chloroform - methanol - glacial acetic acid 90: 10: 5).

While saponifying the methyl ester moiety and the thiol acetic acid ester residue, 2.7 g (3.3 mmol) of the above reaction product are dissolved in 20 ml of methanol and 40 ml of water, and 4 ml of 5N sodium hydroxide are added. After stirring for 1.5 hours, 2 ml of 5N sodium hydroxide was added at room temperature and the mixture was further stirred

1.5 hours. The methanol was distilled off in vacuo, water was added to the residue, and the mixture was shaken with dichloromethane.

The aqueous phase is acidified with dilute hydrochloric acid, the precipitated viscous oil is separated in a separatory funnel, dissolved in a small amount of water and purified by chromatography on 100 g of Dowex 50W x 4 resin, eluting with 5% aqueous pyridine.

There was obtained 700 mg (45.9% of theory) of N- (3-phenyl-2-S-mercaptopropanoyl) -S-lysyl] -thiazolidine-4-S-carboxylic acid which was pure by NMR spectroscopy.

= 0.52 (silica gel; ethyl acetate - butanol - water - acetic acid 1: 1: 1: 1).

Preparation of starting materials

N 4 - (3-phenyl-2-R-bromopropanoyl) - N 4 -tert-butoxycarbonyl-S-lysine

3.25 g (14.2 mmol) of 3-phenyl-2-R-bromopropionic acid and 3.7 g (14.2 mmol) of N, N-tert-butoxycarbonyl-S-lysine methyl ester are dissolved in 70 ml of anhydrous dichloromethane, with stirring and cooling to 0 ° C, 2.9 g (14.2 mmol) of N, N'-dicyclohexylcarbodiimide are added and the mixture is stirred at room temperature overnight. The precipitated dicyclohexylurea is filtered off with suction, the solvent is distilled off and the residue is taken up in ethyl acetate. After cooling and re-filtration, the organic phase is washed successively with dilute potassium hydrogen sulphate solution, saturated sodium bicarbonate solution, water and saturated sodium chloride solution, dried over magnesium sulphate and evaporated to dryness in vacuo. A crystalline residue (6.2 g), recrystallized from ethyl acetate / n-hexane, gave 4.8 g (71.1% of theory) of the methyl ester of the title compound, m.p. 97-98 ° C.

R _f = 0.49 (silica gel; ethyl acetate - n-hexane 2: 1).

Rf = 0.7 (silica gel; chloroform-methanol-glacial acetic acid 90: 10: 5).

To saponify the methyl ester moiety, 4.8 g (10.2 mmol) of (3-phenyl-2-R-bromopropanoyl) -4-tert-butoxycarbonyl-S-lysine methyl ester is dissolved in 50 ml of methanol and the solution is dissolved in water with cooling 11 ml of 1N sodium hydroxide solution (11 mmol) was added with ice and stirring. After stirring at room temperature for 3 hours, the methanol was evaporated in vacuo, the aqueous residue was diluted with water, and the resulting cloudy solution was acidified with 5% potassium bisulfate solution and extracted with dichloromethane. The crystalline product precipitated from the dichloromethane solution was filtered off with suction (2.32 g) and a further 2 g of crystalline material were obtained from the filtrate. The two fractions were combined and recrystallized from chloroform with a small amount of methanol. 3.1 g (66.4 l of theory) of the title compound melting at 178 DEG-179 DEG C. are obtained.

R _f = 0.55 (silica gel, chloroform - methanol - glacial acetic acid 90: 10: 5).

Example 3

N- [3- (3-phenyl-2-S-acetylmercaptopropanoyl) -S-lysyl] -thiazolidine-4-S-carboxylic acid.

The S-acetylderivative of the title compound of Example 2 is obtained by repeating the procedure of Example 2 except that the thiazolidine-4-S-carboxylic acid tert-butyl ester is used in place of the thiazolidine methyl ester and the target is saponified in a single reaction step. butyl ester moiety in the reaction product while leaving the protecting group at the terminal nitrogen.

Example 4

N- (N-N- (3-phenyl-2-S-mercaptopropanoyl) -S-lysyl) -S-proline

To a solution of 0.989 g (13 mmol) of thiol acetic acid in 45 ml of anhydrous ether and 1.31 g (13 mmol) of triethylamine, a solution of 3.7 g (6.5 mmol) of (3-phenyl-2-) methyl ester is added dropwise with stirring. R-bromopropanoyl) tert-butoxycarbonyl-S-lysyl] -S-proline in 30 ml of ethyl acetate. The reaction mixture was heated to reflux, then cooled, filtered and the filtrate was washed successively with dilute potassium bisulfate solution, sodium bicarbonate solution, water and saturated sodium chloride solution, dried over magnesium sulfate, and the solvent was distilled off in vacuo. 4.0 g of a yellowish oil are obtained, which is purified by chromatography on 120 g of silica gel, eluting with ethyl acetate / n-hexane (2: 1). 3.0 g (81.9% of theory) of pure (3-phenyl-2-S-acetylmercaptopropanoyl) -N-tert-butoxycarbonyl-S-lysyl] -S-proline methyl ester are obtained in the form of a colorless oil.

Rf = 0.26 (silica gel; ethyl acetate-n-hexane 2: 1).

Cleavage of the protecting groups as described in Example 2 gave 1.7 g (78.7% of theory) of the title compound.

Rf = 0.52 (silica gel; ethyl acetate-butanol-water-acetic acid 1: 1: 1: 1). Example 5

The β-diastereomer analogous to the product prepared in Example 4 is obtained by using the R-bromo derivative of the corresponding S-isomer, i.e. the N-N (N-O-phenyl-2-S-bromopropanoyl) -N-4-tert-methyl ester. butoxycarbonyl-S-lysyl] -S-proline.

Rf = 0.44 (silica gel; n-butanol-glacial acetic acid-water 3: 1: 1).

Example 6 N-N '- (3-Phenyl-2-S-acetylmercaptopropanoyl) -S-lysyl] -S-proline (5-methyl-2-oxo-1,3-dioxolen-4-yl) methyl ester

A. 2.6 g (4.7 mmol) Ν- £ ^ν λ - (3-phenyl-2-R-bromopropanoyl) -N ^S -tert-butoxycarbonyl-S-lysyl] -S-proline were dissolved in 400 ml of acetone and 500.5 mg (5 mmol) of potassium bicarbonate, 141 mg (0.85 mmol) of potassium iodide and 965 mg (5 mmol) of 4-bromomethyl-5-methyl-2-oxo-1,3 are added successively. --dioxolene. The reaction solution was stirred and refluxed under nitrogen for 3 hours, then cooled and filtered to remove insoluble material. The solvent was distilled off, the residue was dissolved in ethyl acetate, the solution was washed with saturated sodium bicarbonate solution, water and saturated sodium chloride solution, dried over magnesium sulfate and the ethyl acetate was distilled off in vacuo. Evaporation mass

2.8 g is purified by chromatography on 90 g of silica gel using a 2: 1 mixture of ethyl acetate and n-hexane as eluent. 2.3 g (73.4% of theory) of an oily product are obtained which, according to NMR spectroscopy, corresponds to the corresponding proline (5-methyl-2-oxo-1,3-dioxolen-4-yl) methyl ester.

Rf = 0.68 (silica gel; ethyl acetate-n-hexane 2: 1).

B. To replace bromine with acetylmercapto, 0.7 g (6.9 mmol) of triethylamine was slowly added to a solution of 525 mg (6.9 mmol) of thiol acetic acid in 20 ml of anhydrous ether under ice-cooling, and the resulting solution was stirred with stirring. dropwise to a solution of 2.3 g (3.5 mmol) of the above bromo derivative in 20 mL of anhydrous ether and 10 mL of ethyl acetate. The reaction mixture was refluxed for a further 90 minutes, cooled, filtered and washed successively with dilute potassium hydrogen sulphate solution, sodium bicarbonate solution, water and saturated sodium chloride solution. After drying over magnesium sulfate, the solvent was distilled off in vacuo. 2.3 g of a yellowish oil are obtained which, after chromatographic purification on 7.5 g of silica gel using ethyl acetate / n-hexane (2: 1) as eluent, yields 1.7 g (74.4% of theory) ( 5-methyl-2-oxo-l, 3-dioxolen-4-yl) N- [N ^a - (3-phenyl-2-S-Acetylmercaptopropanoyl) -N-tertbutoxycarbonyl-S-S-lysylJ -proline.

C. To cleave the N-tert-butoxycarbonyl protecting group of the lysine residue, 1.7 g (2.57 mmol) of the product prepared in the stupefaction was stirred at room temperature with ml of trifluoroacetic acid for 3 hours, then evaporated to dryness in vacuo. and the residue was dissolved in acetone and chloroform three times in succession to remove residual trifluoroacetic acid and evaporated again. 2.3 g of the title compound are obtained.

Example 7

N- (3-phenyl-2-S-mercaptopropanoyl) -N-tert-butoxycarbonyl-S-lysyl] -S-proline

3.9 g (6.9 mmol) of methyl Ы- ^[ы г - (3-phenyl-2-S-Acetylmercaptopropanoyl) -N ^{'-tert-butoxycarbonyl-S-S-lysylJ-proline} (synthesized according to Example 2) The reaction mixture was saponified for 3 hours under nitrogen at room temperature with 10.5 ml of 5N sodium hydroxide in 40 ml of 50% aqueous methanol.

This afforded 2.9 g of the title compound as a white amorphous solid.

Rf = 0.57 (silica gel; chloroform-methanol-glacial acetic acid 90: 10: 5). EXAMPLE N-N '- (3-Phenyl-2-S-acetylmercaptopropanoyl) -N-tert-butoxycarbonyl-S-lysyl (5-methyl-2-oxo-1,3-dioxolen-4-yl) methyl ester -S-proline

A. N- (N '- (3-phenyl-2-R-bromopropanoyl) -N ^fc -tert-butoxycarbonyl-S-lysyl [-S-proline

The title compound was prepared from 13.2 g (28.9 mmol) of N ^'and - (3-phenyl-2-bromopropanoyl) -N-tert. butoxycarbonyl-S-lysine and 4.8 g (28.9 mmol) of methyl ester of S-proline hydrochloride by the condensation method described in Example 2, using N, N'-dicyclocarbodiimide as condensing agent.

12.8 g of crude oily reaction product are obtained which, after chromatographic purification (silica gel; ethyl acetate-n-hexane 2: 1), yields 8.9 g (54% of theory) of the title compound as an amorphous solid.

B. To saponify the methyl ester of paragraph A, 4 g (7 mmol) of this compound is dissolved in 40 ml of methanol, 7.5 ml (7.5 mmol) of 1N sodium hydroxide are added and the mixture is stirred at room temperature for 3 hours. . The methanol is distilled off in vacuo, the residue is diluted with water and acidified with dilute potassium hydrogen sulphate solution. The precipitated solid material is filtered off with suction and, after washing with water, dried in vacuo over phosphorus pentoxide.

S * «

Yield: 3.4 g (87.6% of theory).

R _f = 0.6 (silica gel, chloroform - methanol - glacial acetic acid 90 * 10: 5).

C. (5-Methyl-2-oxo-1,3-dioxolen-4-yl) methyl N-N- (3-phenyl-2-R-bromopropanoyl) -N-tert-butoxycarbonyl-S-lysyl ester -S-proline

2.6 g (4.7 mmol) of the acid prepared in V are dissolved in 40 ml of acetone and 500.5 mg (5 mmol) of potassium bicarbonate, 141 mg (0.85 mmol) of potassium iodide and 965 are added successively. mg (5 mmol) of 4-bromomethyl-5-methyl-2-oxo-1,3-dioxolene. The reaction solution was stirred and refluxed under nitrogen for 3 hours, then cooled and freed from precipitated potassium chloride by filtration. The filtrate was evaporated in vacuo, the residue was dissolved in ethyl acetate, washed with saturated sodium bicarbonate solution, water and saturated sodium chloride solution, dried over magnesium sulfate, and ethyl acetate was distilled off in vacuo. The oil (2.8 g) was purified by chromatography on silica gel using ethyl acetate / n-hexane (2: 1) as eluent. 2.3 g (73.4% of theory) of an oily product are obtained which, according to NMR spectroscopy, corresponds to the title compound.

R _f = 0.68 (silica gel; ethyl acetate - n-hexane 2: 1).

D. (5-Methyl-2-oxo-1,3-dioxolen-4-yl) methyl ster N-IN '- (3-phenyl-2-S-acetylmercapto) -N * -tert-butoxycarbonyl- L-lysyl-5-proline

700 mg (6.9 mmol) of triethylamine are slowly added to a solution of 525 mg (6.9 mmol) of thiol acetic acid in 20 ml of anhydrous ether under nitrogen, and a solution of 2.3 g (3 g) is added dropwise with stirring. (45 mmol) of the bromo derivative from Part C in 20 mL of anhydrous ether and 10 mL of ethyl acetate. The reaction mixture was refluxed for a further 90 minutes, cooled, filtered and washed successively with dilute potassium hydrogen sulphate solution *, sodium bicarbonate solution, water and saturated sodium chloride solution. After drying over magnesium sulfate, the solvent was distilled off in vacuo. The residue is obtained as a residue

2.3 g of the title compound which, after chromatographic purification on silica gel with ethyl acetate / n-hexane (2: 1) as eluent, afforded 1.7 g (74.4% of theory) of the title compound as a colorless solid. viscous oil.

R f = 0.21 (ethyl acetate-n-hexane 2: 1).

The following compounds can also be prepared in an analogous manner to the previous examples:

N £ n ^X - (3-phenyl-2-S-mercaptopropanoyl) -N- ^£ -acetyl-S-lysyl] -S-proline;

Rf ₌ 0.49 (silica gel; butanol-acetic acid-water 3: 2: 1);

ival- (N - (3-phenyl-2-S-acetylmercaptopropanoyl) -S-lysyl) -5-proline pivaloyloxymethyl ester;

R _f = 0.36 (silica gel; ethyl acetate - methanol 9: 1).

N-N, N '- (3-phenyl-2-S-acetyl-mercaptopropanoyl) -S-lysyl] thiazolidine-4-S-carboxylic acid pivaloyloxymethyl ester.

RSS diastereomers analogous to those listed above, specifically Γν Ν-N - (3-phenyl-2-R @ 1 -acetyInierkaptopropanoy) -S-lysis] .beta.-proline and N-JN ^C - (3-phenyl-1-2-R -mercaptopropanoyl) -N (N '- acetyl-S-lysyl) -S-proline, are obtained by using the corresponding S-isomer, i.e. 3-phenyl-2-, as the starting material instead of the R-bromo derivative. S-bromopropionic acid.

The following are examples of compositions and preparations of pharmaceutical compositions containing the compounds of the invention.

(a) Dragees

One dragee core contains:

active ingredient according to the invention 10.0 mg milk sugar 60.0 mg cornstarch 35.0 mg gelatine 3.0 mg magnesium stearate 2.0 mg total 110.0 mg

Preparation:

After moistening with a 10% aqueous gelatin solution, the active ingredient / milk starch mixture is granulated through a 1 mm sieve, dried at 40 DEG C. and passed through a sieve. The resulting granulate is mixed with magnesium stearate and dragee cores are pressed from the mixture. The cores thus obtained are conventionally coated with an aqueous suspension of sugar, titanium dioxide, talc and gum arabic. The finished dragee is then polished with beeswax.

(b) Tablets

Ingredients:

active ingredient according to the invention

10.0 mg

milk sugar 70.0 mg cornstarch ·· 50.0 mg soluble starch 7.0 mg magnesium stearate 3.0 mg

total 140.0 mg

Preparation:

The active ingredient and magnesium stearate are granulated using an aqueous solution of soluble starch, the granulate is dried and thoroughly mixed with milk sugar and corn starch. The mixture is then compressed into tablets weighing 230 mg each containing 100 mg of the active ingredient.

c) Solution for injection

Ingredients:

active ingredient according to the invention 5.0 mg ethanolamine 60.0 mg sodium chloride 20.0 mg distilled water make up to 2 ml

Preparation:

The active ingredient, together with the excipients, is dissolved in a sufficient quantity of distilled water and made up to the desired concentration with the necessary amount of water. The solution is filtered and aseptically filled with 2 ml ampoules. The ampoules are sterilized and sealed. Each ampoule contains 5 mg of active substance.

(d) Capsules

Ingredients:

active ingredient according to the invention 10.0 mg milk sugar 250.0 mg cornstarch 40.0 mg talc 10.0 mg total 310.0 mg

Preparation:

The active ingredient, milk sugar and corn starch are first mixed in a suitable mixer and then milled in a mill. The resulting mixture is again transferred to a mixer, mixed thoroughly with talc and filled into hard gelatin capsules by machine.

(e) Suppositories

Ingredients:

active ingredient according to the invention 0/1 g cocoa butter (melting point 36-37 ° C). 1.6 g carnauba wax M 9  total 1/8 g

Preparation:

Cocoa butter and carnauba wax are melted, mixed thoroughly and cooled to 45 ° C.

A finely pulverized active substance is mixed into this mass, the mixture is then poured into slightly pre-cooled rosehip molds of appropriate size and allowed to cool.

Claims (1)

SUBJECT OF THE INVENTION A process for the preparation of amino acid derivatives of formula I NHR (I) in which is hydrogen or acetyl, R represents a hydrogen atom, an acetyl group or a tert-butoxycarbonyl group and A is proline, 4-carboxythiazolidin-3-yl, proline (5-methyl-2-oxo-1,3 dioxolen-4-yl) proline, proline O-pivaloyloxymethyl or 4- (pivaloyloxymethoxycarbonyl) thiazolidin-3 an alkyl radical, wherein the aforementioned radicals are linked by a peptide bond through the nitrogen atom and their salts, characterized in that the compound of formula II NHR in which Br (CH3) ₄ I I CH ₂ -CH-CO-NH-CH-CO-A (II) R and A are as defined above, reacted with a mercapto compound of formula III Wherein - (III) n is as defined above and the resulting compound of formula (I) is optionally converted