SU1660578A3 - Method for synthesis of n-[3-(n-cyclopentacarbonyl-d-alanylthio)-2-d- methylpropanoyl]-l-proline - Google Patents

Abstract

The invention relates to the preparation of N- / 3- (N-cyclopentacarbonyl-D-alanylthio) -2D-methylpropanoyl] -L-proline, which has an antihypertensive effect, which can be used in medicine. The goal is to create a new active and low toxic compound of the indicated class. Synthesis is carried out by condensation of N-cyclopentacarbonyl-D-alanine (obtained from a cyclopentacarbonyl derivative with D-alanine) with 3-mercapto-2-D-methylpropionic acid in the presence of dicyclohexylcarbodiimide and N-oxide of succinimide, followed by treatment of the obtained product with a third. butyl ester of L-proline in the presence of dicyclohexylcarbodiimide and then a solution of trifluoroacetic acid in anisole medium (cleavage of the tert. butyl-protecting group). The novel compound at a dose of 40 mg is longer than 100 mg of captopril, less toxic and more resistant to hydrolysis with a longer shelf life. 1 tab.

Description

The invention relates to methods for preparing N- | 3- {M-cyclopentacarbonyl-0-alanylthio) -2-O-methylpropanoyl-L-proline, a novel biologically active compound that can be used in medicine.

The purpose of the invention is to obtain a new derivative in a series of peptides with antihypertensive activity, low toxicity, more resistant to hydrolysis, having a longer shelf life, which does not give undesirable side effects.

 Step 1. Preparation of M-cyclopenta-carbonyl-O-alanine,

O-Alanine (4.5 g) was dissolved in 230 ml of native 1N. sodium carbonate solution at

stirring. 100 ml of tetrahydrofuran containing 9 g of cyclopentacarbonyl chloride are added dropwise to the solution at 5-10 ° C and at this temperature the mixture is stirred for 30 minutes, then stirred at room temperature for 1.5 hours. Then, 2 n is added to the reaction mixture. . hydrochloric acid so that the pH is between 1 and 2. The reaction mixture is extracted with ethyl acetate. the organic layer is washed with a saturated solution of sodium chloride and dried over magnesium sulfate. The filtrate is evaporated under vacuum to obtain a crude product. By recrystallization from ethyl acetate - n-hexane, 4.65 g of M-cyclopentarbonyl-D-alanic are obtained.

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Stage 2. Preparation of 3- (M-cyclopenecarbonyl-0-alanylthio) -2-0-methylpropanoic acid.

M-Cyclopentacarbonyl-O-alanine (5.97 g) is dissolved in dried tetrahydrofuran (10 ml). Carbonyldiimidazole (5.84 g) is added to the solution at a temperature between -20 and -15 ° C, the mixture is stirred at this temperature for 1 hour. Then, 3-mercapto-2-O-methylpropanoic acid (3.60 g) is added and the mixture is stirred at a temperature between -15 and -10 ° C for 1 h, then at room temperature another 1 hour. The mixture is evaporated under vacuum to remove the solvent. 40 ml of water are added to the residue and 2N is added to the mixture. hydrochloric acid, acidified to a pH between 1 and 2. The mixture is extracted with ethyl acetate, the organic layer is washed with a saturated solution of sodium chloride (2 times) and dried over magnesium sulfate. The filtrate is evaporated under vacuum to obtain a crude compound. When it is recrystallized from ethyl acetate - / n-hexane, colorless prisms of the title compound are obtained.

Stage 3. Preparation of M-3-M (M-cyclopentacarbonyl-0-alanylthio) -20-methylpropanoyl} -1-proline,

3- (M-Cyclopentacarbonyl-0-alanyl-o-o) -2-0-methylpropanoic acid (1.51 g) is dissolved in dried tetrahydrofuran (40 ml). To this solution, 0.61 g of triethylamine and 0.65 g of ethyl chloroformate are added at -5 ° C with stirring. After 5 minutes, a solution containing 0.58 g of L-proline and 0.61 g of triethylamine in 5 ml of water was added, and the mixture was stirred at 0 ° C for 1 hour, then at room temperature for 30 minutes. The mixture is evaporated under vacuum to remove the solvent. After water was added to the residue, 2N was added to the mixture. hydrochloric acid, acidified to a pH between 1 and 2. The reaction mixture is extracted with ethyl acetate, the organic layer is washed with a saturated solution of sodium chloride (2 times) and dried over magnesium sulfate. The filtrate is concentrated under vacuum to remove ethyl acetate, and the residue is separated by chromatography on a flask using a mixture of chloroform and methanol in a ratio of 100: 1-100: 2 as eluant. The fractions containing the final compound are collected and evaporated under vacuum to give a resinous sample of this compound (0.3 g, 49%). The purity and uniformity of the product obtained is determined by silica gel chromatography.

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, 62 (chloroform - methanol - acetic acid 2: 1: 0.003). 74 (n-butanol - acetic acid - water 4: 1: 1). , 2 (, methanol).

Biological tests of N- {3- (M-cyclopentacarbonyl-O-ananylthio) -2-0 -methylpropanoyl -1 -proline obtained by the proposed method were carried out in rats.

The table shows the average percentage of inhibition induced by elevated pressure caused by the administration of the compound obtained by the proposed method and captopril in the amount of 0.4 mmol / kg.

From the table it can be seen that the compound obtained by the proposed method exhibits an antihypertensive effect compared with the effect of captopril at the selected dosage level. However, the aforementioned compound is more stable than captopril, both in biological media and in other conditions. Conducted in vitro tests show the stability of this compound under conditions of degrading media of tissue and plasma homogenates. Experiments have shown that captopril rapidly decomposes to its disulfide and other metabolites, which are inactive as inhibitors.

After 60 minutes of incubation with the plasma of rats, humans, monkeys, and dogs, the number of 35S captopril is always 0; 7, 10, 25% respectively; the main product was disulfide.

The supernatant fraction 9000 xd of the homogenate of the liver, kidney and intestine of rats almost completely translates captopril into its disulfide and other products for 120 minutes. The half-life of captopril in aqueous solutions is 30 min. In addition, M-3-M-cyclopentacarbonyl-0-alanylthio} 2-O-methylpropanoyl1-L-proline shows a low efficacy over a period of 90-180 minutes after oral administration.

Captopril reaches peak efficiency by 90 minutes, then it falls. After 180 minutes (M-cyclopenta-. Carbonyl-O-alanylthio) -2-0-methyl | -1-proline is a more effective inhibitor without any signs of weakening its reaction.

Comparative studies in healthy people have shown that the effect of 40 mg (0.096 mmol) M- | 3- {M-cyclohexylcarbonyl-D-ala nylthio) -2-0-methyl p-ropan oiol-Ln rolin lasts longer than the effect of 100 mg (0.46 mmol) of captopril.

Thus, the N-Ј3 - {N-cyclopentacarbonyl-0-alanylthio) -2-0-methylpropanoyl} obtained by the proposed method - L-pro-in - compound is low-toxic, more hydrolysis resistant than captopril, has a longer storage time. and easier to handle.

Claims (1)

The invention The method of obtaining 1 - / 3- {N-cyclopenta-carbonyl-0-alanylthio) -2-0-methylpropano-yl) -1 -proline formula D .. C-MH-CH-CO-S-CH2-CH-CO-N about CH, CH, soon characterized in that 1M-cyclope "is tacarbonyl-O-alanine of the formula Goose n-snsoon L- / C | OCH3 obtained by the interaction of cyclopentacarbonyl derivative with D-alanine, condensed in the presence of dicyclohexyl of carbodiimide and N-oxysuccinimide with 3-mercapto-2-O-methylpropionic acid and the resulting condensation product of 3- {N-cyclopentarbonyl-0-elanylthio) -2-O-methylpropanoic acid ten PG C-YAN-CH-CO-S-CH, -CH-COOH L- I | g | oh nooh introduced into reaction with L-proline t-butyl ether in the presence of dicyclohexylcarbodiimide and from the obtained 15 products (M-cyclopentacarbonyl-0-alanylthio) -2-0-methylpropanoyl-L-proline O-c-ln-cd-c-cng-cn-np 2Q ° Ш3СНзСООС4Н9тргт 25 by treating with a solution of trifluoroacetic acid in anisole, a tert-butyl protecting group is cleaved. (cyclopetacarbo-, nyl-B-alanylthio) -2-B-methylpropanoyl-L-npo1 LIN Captopril 21 46 35 56 42 58 42 48 42 37