FI95569B - Method for the preparation of new organic nitrates - Google Patents

Abstract

Organic nitrates with a specific structure, consisting of nitrato fatty acids (nitratoalkanoic acids) and sulphur-containing amino acids or peptides, of the general formula <IMAGE> in which the symbols have the meanings specified in the claims. Because of the general structural principle - presence of sulphhydryl groups - they prevent nitrate tolerance or attenuate a tolerance which has already occurred. The compounds are used in medicaments for treating circulatory disorders, high blood pressure, heart failure and for dilating peripheral vessels.

Description

x 95569

Method for the preparation of new organic nitrates

The invention relates to a process for the preparation of new organic nitrates.

Organic nitrates (esters of nitric acid) have been shown to be useful in the treatment of heart disease. They work both by reducing the load on the heart by reducing the pre- and post-load and by improving oxygen uptake by dilating the coronary artery.

In recent years, however, it has been found that in the case of the organic nitrates used so far, such as glycerol trinitrate (GTN), isosorbide-5-mononitrate or isosorbide dinitrate, the body shows a clear weak effect over a relatively short period of time when these nitrates are used continuously and in high doses. i.e. nitrate tolerance. Numerous experiments have shown that the presence of sulfhydryl groups can inhibit the development of nitrate tolerance and impair already developed tolerance.

The mechanism for the development of nitrate tolerance is currently assumed to be as follows. According to current knowledge. the pharmacological effect of organic nitro compounds depends on the presence of wood cysteine. Organic nitrate forms a common precursor with cysteine, the decomposition of which results in e.g. For the release of NO radicals. These radicals, in turn, activate the target enzyme, soluble guanylate cyclase in smooth muscle cells. Subsequent reactions triggered by cGMP formation then lead to triggering or vasodilation.

The reactive and short-lived, still hypothetical intermediate is probably nitric acid thioester or thionitrate. Intramolecular rearrangements and other, as yet unexplained, reactions are thought to eventually lead to the formation of nitrosothiol, from which nitrosothiol or nitrite ions are then released. In contrast, enzyme-dependent degradation by GSH reductase is likely to be insignificant to the pharmacological effect, as it results exclusively in the formation of nitrite ions. Thus, as mentioned above, non-enzymatic degradation requires the presence of cysteine and can thus be brought to a dose-dependent stop (depletion of all SH groups) so that sufficient nitric oxide NO, which acts as the actual activator of guanyl cyclase, can no longer be formed, resulting in clinically relevant to the decrease in effect.

The substances obtained by the process of the invention are structurally specific compounds consisting of nitrate fatty acids (nitroalkanoic acids) and sulfur-containing amino acids or peptides.

Accordingly, it is an object of the present invention to provide novel organic nitrates which, due to their general structure, i.e. the presence of sulfhydryl groups, are characterized in that the formation of nitrate tolerance is prevented or the already developed tolerance is impaired.

This object is achieved by compounds of the general formula: R1 0 R3 R4 0

I II I I II

02N-O-C- (CH2) m-C-N-C-C-R

12 R 2 R 5 wherein R is hydroxy, lower alkoxy or amino; R 1 is hydrogen or alkyl of 1 to 6 carbon atoms; R 2 is hydrogen or lower alkyl; R 3 is hydrogen or lower alkyl,; . ID i anti I I I M | 3,956,9 R4 is hydrogen or lower alkyl; R 5 is mercaptomethyl, mercaptoethyl, methylthioethyl, its S-acyl derivatives, especially S-acetyl, S-propionyl, S-butyryl, S-capronyl, S-capryl, S-isobutyryl, S-pivaloyl or S-benzoyl; R and R5 may be bonded together to form a thiolactone; m has a value of 0-10; as well as pharmaceutically acceptable salts of these compounds.

According to one embodiment of the invention, the nitrate fatty acids acting as components have a chain length of 2 to 6 carbon atoms. They may be straight-chain, branched, racemic or optical isomers.

The invention preferably uses cysteine, methionine or homocysteine as amino acids.

These amino acids are preferably in stereochemical L-form.

The cysteine and / or methionine may be in the form of its methyl, ethyl or propyl ester.

The SH group of the cysteine may be esterified with a lower alkanecarboxylic acid having 2 to 8 carbon atoms.

According to a particularly preferred embodiment of the invention, the process according to the invention gives compounds of the following chemical formulas: N- (2-nitrateacetyl) -cysteine ethyl ester N- (2-nitrate-acetyl) -S-acetyl-cysteine ethyl ester N- (2-nitrate-acetyl) -S-propionyl- cysteine ethyl ester 4 95569 N- (2-nitrateacetyl) -S-pivaloyl cysteine ethyl ester N- (2-nitrateacetyl) methionine methyl ester N- (2-nitrate propionyl) cysteine N- (2-nitrate propionyl) cysteine ethyl ester N- (2- Nitrate-propionyl) -methionine-ethyl ester N- (2-nitrate-butyryl) -cysteine N- (2-nitrate-butyryl) -cysteine-ethyl ester N- (2-nitrate-butyryl) -S-acetyl-cysteine-ethyl ester N- (2-nitrate-butyryl) -S-butyryl-cysteryl (2-Nitrate-butyryl) -methionine ethyl ester N- (2-nitrate-isobutyryl) -cysteine N- (2-nitrate-isobutyryl) -cysteine-ethyl ester N- (2-nitrate-isobutyryl) -S-benzoyl-cysteine-ethyl ester N- (2-nitrate-isobutyl) over) -S-acetyl-cysteine-ethyl ester N- (2-nitrate-isobutyryl) -S-pivaloyl-cysteine-ethyl ester N- (2-nitrate-isobutyryl) -methionine-ethyl ester N- (3-nitrate-butyryl) -cysteine N- (3-nitrate-butyryl) -cysteine ethyl ester N- (3-nitrate-butyryl) -S-acetyl-cysteine-ethyl ester N- (3-nitrate-butyryl) -S-propionyl-cysteine-ethyl ester N- (3-nitrate-butyryl) -methionine-ethyl ester N- (3-nitrate-butyrylthiocinyl) thiocinyl (3-Nitrate-pivaloyl) -cysteine N- (3-nitrate-pivaloyl) -cysteine ethyl ester N- (3-nitrate-pivaloyl) -cysteine-ethyl ester S-carbonate N- (3-nitrate-pivaloyl) -S-acetyl-cysteine-ethyl ester N- (3-nitrate-pivaloyl) ) -S-propionyl-cysteine ethyl ester N- (3-nitrate-pivaloyl) -S-butyryl-cysteine-ethyl ester N- (3-nitrate-pivaloyl) -S-isobutyryl-cysteine-ethyl ester! ia * t MU IIIM <5 95569 N- (3-Nitrate-pivaloyl) -S-pivaloyl-cysteine-ethyl ester N- (3-nitrate-pivaloyl) -S-benzoyl-cysteine-ethyl ester N- (3-nitrate-pivaloyl) -methionine-ethyl ester N- ( 3-Nitrate-pivaloyl) -methionine N- (3-nitrate-pivaloyl) -homocysteine thiolactone N- (2-nitrate-hexanoyl) -cysteine ethyl ester N- (2-nitrate-hexanoyl) -S-propionyl-cysteine-ethyl ester-N- (3-nitrate-ethyl) -hexanoate (3-Nitrate-hexanoyl) -methionine methyl ester N- (12-nitrate-lauroyl) -cysteine N- (12-nitrate-lauroyl) -cysteine ethyl ester N- (12-nitrate-lauroyl) -S-acetyl-cysteine N- (12-nitrate-lauroyl) -S-pivaloyl cysteine

The compounds obtained by the process of the invention can be used as a medicament containing a certain concentration of one compound of the invention and / or a mixture of these compounds. These drugs can be used to treat circulatory diseases, for example, as a dilator of coronary arteries, to treat hypertension and heart failure, and to dilate peripheral blood vessels, brain and kidney blood vessels, including Lukin.

In addition, these compounds can be prepared in a manner known per se by condensing the corresponding nitrate fatty acids or their reactive derivatives with the amino group of the amino acid. Optionally, the side chains of the resulting compounds can be alkylated or the alkane mercapto groups acylated by a further reaction.

The essential features of the invention are set out in the appended claims.

6 95569

Reactive derivatives of nitrate fatty acids used according to the invention are, for example, acid halides, acid anhydrides, activated amides or activated esters. Preferred are acid chloride, acid azide, symmetrical acid anhydrides, activated esters and mixed anhydrides with organic or inorganic acids.

Condensation reactions between nitrate fatty acids and amino groups of amino acids can also be carried out in an inert solvent and a condensation agent which promotes the formation of acid amide bonds, a carbodiimide such as N, N'-dicyclohexylcarbodiimide or another similar carbodiimide in the presence of pentamethylene ketene-N-cyclohexylimine, or a phosphate or phosphite such as triethyl phosphite, ethyl polyphosphate or isopropyl phosphate for 1 to 48 hours at temperatures from -10 ° C to the reflux temperature of the solvent used.

The following embodiments illustrate the invention without limiting it in any way.

Example 1 Preparation of N- (3-nitrate-butyryl) -cysteine ethyl ester Step I: Saponification of 3-hydroxybutyric acid ethyl ester To 13.2 grams (0.1 mol) of 3-hydroxybutyric acid ethyl ester (Aid-rich) was added 4.0 g (0.1 mol) of NaOH. dissolved in 100 ml of 7 95569 water. The reaction was complete when the solution had become homogeneous. The reaction mixture was worked up by acidifying the resulting solution with 10 ml of concentrated hydrochloric acid HCl and extracting twice with 100 ml of ethyl acetate each time.

The solution was then concentrated on a rotary evaporator to leave a thin oil. The yield was 8.81 g (theoretical yield: 10.4 g) of 3-hydroxybutyric acid.

Working step II: Nitration of 3-hydroxybutyric acid 8.81 g (0.08 mol) of 3-hydroxybutyric acid and 50 mg of urea were dissolved in 50 ml of acetic acid at 5 ° C. To this solution was then added dropwise 6.27 ml (0.15 mol) of nitric acid HNO3, followed by cooling with 14.17 ml (0.15 mol) of AcaO. The reaction mixture was stirred overnight.

The reaction mixture was worked up by adding 200 ml of ice water to the resulting solution and extracting with ethyl acetate. The organic phase was extracted with NaHCO 3. The NaHCO 3 phase was acidified with concentrated hydrochloric acid HCl and extracted with ethyl acetate. Finally, the solution was concentrated on a rotary evaporator to leave a thin oil. The yield was 9.4 g (theoretical yield: 11.9 g) of 3-nitrate butyric acid.

Working step III Preparation of N- (3-nitrated butyryl) -cysteyl ethyl ester 16.6 g (0.11 mol) of 3-nitrated butyric acid were dissolved in 100 ml of dichloromethane a. To this solution was slowly added, under nitrogen 175 g (0.12 mol) of cysteine ethyl ester at 1 ° C. The mixture is then slowly added dropwise at 15 ° C with nitrogen, giving 24.7 g (0.12 mol) of dicyclohexylcarbodiimide (DCC) dissolved in 80 ml of dichloromethane. After completion of the reaction, the dicyclohexylurea formed was filtered off with suction and the solution was washed with 150 ml of 0.1 N hydrochloric acid. The solution was then concentrated on a rotary evaporator.

· 8 95569

Further purification of the material was carried out by preparative column chromatography and recrystallization from a mixture of ethanol and n-hexane. The yield was 6.88 g (theoretical yield: 30, B3 g). Sp. 77.8 ° C.

Example 2 Preparation of N- (3-nitrate butyryl) methionine ethyl ester 6.35 g (0.043 mol) of 3-nitrate butyric acid, 7.47 g (0.043 mol) of methionine ethyl ester and a spatula tip of dimethylaminopyridine (DMAP) were dissolved. “Cooling and stirring at 100 ° C in 100 ml of dichloromethane. 10.31 g (0.05 mol) of DCC were dissolved in 80 ml of CH 2 Cl 2 and slowly added dropwise to the mixture under nitrogen. After completion of the reaction, the solution was filtered off with suction, and washed with NaHCl 3 and finally with hydrochloric acid HCl. The solution was concentrated on a rotary evaporator to leave an oil.

Further purification was carried out by the preparative column chromatography method or by crystallization in the cold. The yield was 1.95 g (theoretical yield: 12.05 g) of N- (3-nitrate-butyryl) -methionine ethyl ester as a colorless oil.

Example 3 Preparation of N- (3-nitrate pivaloyl) cysteine ethyl ester Step I:

Preparation of nitric acid methyl ester 25.0 g (0.19 mol) of hydroxypivalic acid methyl ester and 0.12 g of urea were dissolved at room temperature in 250 ml of CH 2 Cl 2 and the solution was cooled to 5 ° C with stirring. At this temperature, stirring the mixture, dropwise 23.8 g (0.3B mol) of 100 X nitric acid so that the temperature does not rise above 10 ° C. The mixture was then cooled to 5 ° C and 38.6 g (0.38 mol) of acetic anhydride were added dropwise with stirring so that the temperature did not rise above 10 ° C. The mixture was stirred for 15 minutes in an ice bath under cooling, after which it was slowly warmed to room temperature and further stirred overnight at room temperature. The reaction mixture was slowly poured, with stirring, into 500 ml of ice water. The CH 2 Cl 3 phase was separated and washed once with 100 ml of distilled water, 100 ml of saturated aqueous NaHCO 3 and a further 100 ml of distilled water. The CH 2 Cl 2 extract was then evaporated to dryness on a rotary evaporator at a water bath temperature of up to 40 ° C under a vacuum produced by a water jet. The pale yellow oily residue was distilled in a vacuum produced by an oil pump at a bath temperature of hO “C” as a clear thin oil. The yield was 31.5 g, i.e. 94.0 X of theory.

Phase II:

Quenching the nitric acid 14.0 g (0.350 mol) of NaOH were dissolved in distilled water and cooled to about 10 DEG C. To this solution, while stirring, 31.0 g (0.175 mol) of nitrate were added. pivamic acid methyl ester dissolved in 250 ml of methanol, whereupon the reaction mixture turned yellow and rose to about 25. The mixture was stirred for 90 minutes, then neutralized with 29.5 ml (0.35 mol) of 37 X hydrochloric acid HCl, and The aqueous phase was extracted twice with 200 ml of methylene chloride each time, the methylene chloride extracts were combined and washed once with 50 ml of distilled water, and then the methylene chloride was evaporated to dryness on a rotary evaporator. , the oily residue was dissolved in 10 ml of ethyl acetate and re-evaporated to dryness on a rotary evaporator to leave a solid white residue. a residue from which residual solvent was removed for 15 minutes on a rotary evaporator under oil pump vacuum (0.4 torr) at a bath temperature of about 40 ° C. A solid white residue weighing 25.44 g (89.1 X of theory) was dissolved in 100 ml of boiling n-hexane and 2 ml of diisopropyl ether were added. The mixture was cooled to room temperature and crystallized embryos were added to crystallize the product. The product was allowed to stand for 72 hours at 0 [deg.] C., after which the crystals were filtered off with suction, washed twice with 10 ml of n-hexane each time and then dried in a vacuum oven at about 2 torr at room temperature under constant pressure. -noon. Sp. 54.2 ° C. Yield: 23.66 g or 82.9 of the 7th theoretical.

Working Step III Quenching of N- (3-Nitrate-pivoyoyl) -cysteine ethyl ester 10.7 g (71.7 mmol) of L-cysteine ethyl ester base were dissolved in 200 ml of methylene chloride under nitrogen at room temperature with stirring. To the solution was added 11.4 g (70.0 mmol) of crystalline nitroxypivalic acid, which was dissolved at room temperature with stirring. To this mixture, 14.8 g (71.7 mmol) of N-N-dicyclohexylurea (DCC) dissolved in 50 ml of methylene chloride was added dropwise, with stirring, under a nitrogen atmosphere over a period of about 15 minutes at room temperature, raising the temperature to 35 ° C. C. As stirring was continued, white di cyclohexylurea precipitated. The reaction mixture was cooled to room temperature and stirred overnight under a nitrogen atmosphere. The dicyclohexylurea was then separated by suction through suction and washed once with 50 ml of methylene chloride in CH 2 Cl 2. The combined methylene chloride solutions were washed once with 100 ml of 1N hydrochloric acid HCl and twice with 100 ml of distilled water each time (under a nitrogen atmosphere) and then evaporated on a rotary evaporator at a bath temperature of about 40 ° C under a water jet vacuum of 550 m at the end about 20 mbar. This gave a light brown oil. Yield: 21.2 g, i.e. 102.9 7. of theory.

The product was purified by cold crystallization from a mixture of ethanol and hexane.

Yield: 13.42 g of 65.1 g of theoretical N- (3-nitrate-p-1-yl) cysteine ethyl ester as a pink oil.

Working step IV: attenuation of N- (3-nitrate pivoyl) -S-acetyl-cysteine ethyl ester •; To 10.3 grams (35.0 mmol) of N- (3-nitrated p-photoyl) -cysteine - and / or vinyl acetate dissolved in 70 ml of dichloromethane was added dropwise, with cold stirring, 4. 3 g (42.0 mmol) of acetic anhydride dissolved in 10 ml of dichloromethane. 5.0 g (49.0 mmol) of triethylamine dissolved in 20 ml of dichloromethane were then added dropwise with cold stirring. After completion of the reaction, the reaction mixture was washed with 1N hydrochloric acid HCl, aqueous sodium bicarbonate and water.

The dichloromethane extract was evaporated to dryness on a rotary evaporator. This gave 11.6 g of a pale yellow oily product which was crystallized in the cold from a mixture of ethanol and water by adding crystalline embryos to give 7.8 g of crystalline product (66.3 7% of theory). Sp. <5 ° C.

Modification of working step IV IV Preparation of N- (3-nitrate pivoyl) -S-butyryl-cysteine ethyl ester

When 6.7 g (42.00 mmol) of butyric anhydride are used instead of the acetic anhydride described in working step IV, the reaction and work-up carried out in the same manner give 13.0 g of a pale yellow oily product, which gives 9.7 g of crystals in the cold as described in working step IV. product (76.2 of the 7th theoretical).

Sp. <5 ° C

IV Working Step II Modification Preparation of N- (3-Nitrate Pivoyl) -S-p-poyloyl Cysteine Ethyl Ester

When 7.8 g (42.00 mmol) of pivalic anhydride are used instead of the acetic anhydride described in working step IV, the same reaction and work-up give 14.1 g of a pale yellow oily product, which crystallizes 10.5 g of crystals as described in working step IV. product (79.5 of the 7th theoretical).

Sp. - 45 ° C.

• · 95569 IV Step IV Modification N- (3-Nitrate Pivoyl) Cysteine Ethyl Ester S-Carbonate

When 4.3 g (42.00 mmol) of ethyl formic acid chloroformate are used instead of the acetic anhydride described in working step IV, the reaction and work-up carried out in the same manner give 11.5 g of a pale yellow oily product, which crystallizes 9 as described in working step IV, 5 g of crystalline product (74.1 from the 7th theoretical). Sp. = 36 ° C.

Example 4 Preparation of N- (3-nitratopyroyl) -methionine ethyl ester 12.4 g (70.0 mmol) of L-methionine ethyl ester base were dissolved in 250 ml of methylene chloride a under a nitrogen atmosphere with stirring at room temperature. 11.4 g (70.0 mmol) of crystalline nitric acid were added, which was dissolved at room temperature with stirring. To this mixture, 14.8 g (71.7 mmol) of N, N-dicyclohexylurea (DCC) dissolved in 50 ml of methylene chloride were added dropwise over about 15 minutes with stirring at room temperature under nitrogen, raising the temperature to 35 ° C. The mixture was further stirred. The reaction mixture was cooled to room temperature and stirred overnight under a nitrogen-air atmosphere, then the DCC-urea was then filtered off through 1-sinter and filtered once with 50 ml of CH 3 Cl 2 and the combined methylene chloride solutions were washed once with 100 ml. 1N hydrochloric acid in HCl and twice in each case with 100 ml of distilled water (under N2), and then evaporated on a rotary evaporator at a bath temperature of about 40 [deg.] C. under a water-1 jet vacuum of 550 mbar at the beginning and about 20 g at the end. mbar to give a pale yellow oil.

Yield: 24.9 g or 110.3 g of the theoretical crude N- (3-nitrated p-photoyl) -L-methionine ethyl ester.

• · «95569

The crude product was purified by preparative flash chromatography. Yield: 17.6 g or 78.0 g of the theoretical N- (3-nitrate pivaloyl) methionine ethyl ester as a colorless oil.

Example 5 Preparation of N- (12-nitrate-lauroyl) -S-acetyl-cysteine Working step I: Preparation of 12-nitrate-lauric acid 54.1 g (0.250 mol) of 12-hydroxy-lauric acid and 0.3 g of urea were slightly dissolved in 1.3 liters of CHCl 3 and cooled to 20 ° C with stirring. While stirring, 23.6 g (0.375 mol) of 100% nitric acid HND3 was slowly added to the mixture, raising the temperature to 27 ° C. The mixture was then cooled to 20 ° C and 38.3 g (0.375 mol) of acetic anhydride were added dropwise with stirring and cooling, keeping the temperature up to 25 ° C. The mixture was stirred at room temperature overnight. It was finally washed five times at a time. The CHCl 3 phase, dried over Na 2 SO 4 and clarified with powdered activated carbon, was evaporated to dryness on a rotary evaporator at a bath temperature of 50 ° C under a water-jet vacuum to give 60.8 g of an oily residue which was dissolved in 500 ml of ice-water. to room temperature and kept in a refrigerator at 0 ° C overnight. The crystallized product was filtered off with suction and washed twice with 50 ml of n-hexane each time. Finally, the product was dried to concentrated weight at room temperature, in a vacuum oven, at a pressure of about 2 torr.

Sp. 29 ° C, yield 39.4 g or 60.3 V. of theory.

Working Step II Preparation of 12-Nitrate Lauric Acid Chloride 2.61 g (10 mmol) of nitrate lauric acid was dissolved in 50 ml of methylene chloride and 4.44 g (35 mmol) of oxalyl chloride in 50 ml of methylene chloride were added dropwise with stirring at room temperature. The mixture was stirred overnight. . Finally, the product was evaporated to dryness on a rotary evaporator.

Yield 3 g or 93.2 7. of theory.

Step III Preparation of N- (12-nitrate-lauroyl) -cysteine 6.06 g (50 mmol) of L-cysteine were stirred in 300 ml of DMF under a nitrogen atmosphere with stirring. 5.60 g (20 mmol) of 12-nitrate-lauric acid chloride a were added dropwise to 50 ml of dichloromethane a. As no clear solution was obtained, the mixture was heated to 60 ° C. Finally, 100 ml of distilled water was added and stirred overnight at room temperature. The mixture was then diluted with 300 ml of distilled water and extracted four times with 200 ml of ethyl acetate each time. The organic phase was dried over Na 2 SO 4 and evaporated. The residue was dissolved in 100 ml of ether and allowed to crystallize overnight in a refrigerator at 0 ° C. White crystals were obtained.

Sp. 74-75 ° C. Yield 4.1 g of N- (12-nitrate-lauroyl) -cysteine.

Step IV Preparation of N- (12-nitrate-lauroyl) -S-acetyl-cysteine 1.82 g (5 mmol) of N- (12-nitrate-lauroyl) -cysteine were first dissolved in 20 ml of ethyl acetate under a nitrogen atmosphere. The mixture was then cooled to 0 ° C and 2.5 ml of acetic anhydride was added. 1.52 g (15 mmol) of triethylamine dissolved in 5 ml of ethyl acetate were then slowly added dropwise at -5 ° C. The reaction solution was washed with water and evaporated to dryness.

Sp. : oily at room temperature. Yield 2 g or 98.4 7. of theory.

Example 6 4 g (26.8 mmol) of cysteine ethyl ester base were dissolved in 50 ml of methylene chloride and 2.8 g (10 mmol) of 12-nitrate lauric acid chloride dissolved in 50 ml of methylene chloride were added to this solution with stirring, and the mixture was stirred overnight. The precipitated cysteine ethyl ester-HCl was removed by suction at 95569 and the solvent was removed on a rotary evaporator. the oily residue (6 g) was dissolved in 100 ml of ether and left overnight in a refrigerator at 0 ° C. The precipitated product was separated by suction.

Sp. 59-60 ° C. Yield 1.6 g or 40.0. of the theoretical.

Example 7 Preparation of N- (2-nitrate-propionyl) -cysteyl ethyl ester Step I:

Preparation of lactic acid ethyl ester 33 g (0.28 mol) of lactic acid ethyl ester was dissolved in 300 ml of dichloromethane a. To the solution was added 100 mg of urea and then at 5-10 ° C dropwise 22.5 ml (0.56 mol) of 100 % nitric acid. The solution was cooled to 0 ° C. 52.8 ml (0.56 mol) of acetic anhydride were then added dropwise so that the temperature did not rise above 5 ° C. The solution was allowed to stand overnight at room temperature, after which it was washed with 250 ml of water. The organic phase was separated and dried over sodium sulfate. The dichloromethane was removed by distillation after filtration. The resulting oily residue was further treated by distillation.

Yield 30.34 g or 66.4 V. of theory. Kp. 34 ° C (0.25 torr).

Phase II of work

Preparation of nitric lactic acid 30 g (0.18 mol) of nitric lactic acid ethyl ester were dissolved in 80 ml of dioxane a. To this solution were added 30 ml of water and 2 g (0.02 mol) of sulfuric acid and refluxed for 19 hours. The solution was evaporated to a volume of about 50 ml and then diluted with 300 ml of water. The pH was adjusted to 7-8 by the addition of sodium hydrogen carbonate. The unreacted ester was removed by extraction with dichloromethane 11a.

The pH of the aqueous phase was adjusted to 1 with concentrated hydrochloric acid and extracted three times with 150 ml of ethyl acetate each time.

.. The extracts were combined and dried over sodium sulfate 1 la. After filtration, the ethyl acetate was completely removed on a rotary evaporator.

Yield 14.6 g or 59.2 7. of theoretical colorless oil.

Working step III Preparation of N- (2-nitratopropylonyl) -cysteyl ethyl ester 17 g (0.13 mol) of nitrate lactic acid and 18.9 g <0.13 mol) of cysteine ethyl ester were dissolved in 10-15 ° C. under a nitrogen atmosphere to 200 ml of dichloromethane a. A solution of 28.6 g (0.14 mol) of N, N-dicyclohexylcarbodiimide and 75 ml of dichloromethane a was added at 15 to 20 ° C.

After 1 hour, the precipitated N-N-dicyclohexylurea was filtered off and washed with 75 ml of dichloromethane. The filtrate was extracted twice with 50 ml of 0.1 N hydrochloric acid each time.

The organic phase was completely evaporated on a rotary evaporator. The crude crystalline product (22.4 g) was recrystallized from 100 ml of a 1: 1 mixture of ethanol and n-hexane.

Yield 7.6 g or 22.6 7. of theory. Sp. 92.8 ° C.

The pharmacological activity of the compounds according to the invention is illustrated by an experimental arrangement.

Pharmacological test set - up 1

The effect of new organic nitrates on the circulatory parameters of the awake dog to show the effect of nitrates

The aim is to determine how these new organic nitrates affect the various circulatory parameters of the awake dog after intravenous and oral administration. All experiments were performed on a trained Beagle dog11a. Circulatory parameters were measured through a conduit placed in an artery with a tip manometer11a and a flushable conduit placed in the jugular vein V. Jugularis.

To illustrate the effect on the thymic system, animals were measured for systolic arterial pressure (SAP), mean arterial pressure (MAP), diastolic arterial pressure (BP) and heart rate (HR).

17 95569 heart rate). From these values, arterial air ventricular-on peripheral resistance (TPR total peripheral resistance) and expansion capacity (COMPL) were calculated. The low pressure system was illustrated by CVP central venous pressure and pulmonary arterial pressure (PAP). Isosorbide-5-mononitrate (ISM-5) was used as a reference.

Attached Figures 1 (Abb. 1: Fig. 1-8) and 2 (Abb. 2:

Figs. 1-8) graphically illustrate the spectrum of action of the organic nitrates according to the invention.

Figure 1 shows the effect of ISM-5 administered orally and intravenously. When given either way, ISM-5 slightly lowers systolic blood pressure, the effect on mean pressure is negligible, the ability of the air chamber to expand is greatly increased, and the pressures in the low-pressure system are reduced.

Figure 2 shows the corresponding effects of N- (3-nitrate-pivaloyl) -methionine ethyl ester (Nitrato-Piv-Meth-Et) in the corresponding parts of the circulation. Also in this case, a comparison between intra-arterial and oral administration shows good bioavailability.

In the case of N- (3-nitrate pivaloyl) cysteine ethyl ester, bioavailability is similarly found to be good and has a typical effect on nitrates.

The results show that both compounds tested have an effect comparable to ISM-5, with good bioavailability.

Pharmacological test set - up. The effect of new organic nitrates on the increase in flow in the coronary arteries in the case of individually flushed hearts to demonstrate undeveloped tolerance The aim of this study was to investigate the effect of new organic nitrate compounds and the development of tolerance in the case of separate, β 95569 1flushed rat hearts. For this purpose, the rat heart was isolated and prepared as a working heart.

In this experiment, the heart does a certain rotational work, which results in a certain amount of oxygen consumption and a certain amount of coronary flow. The effect of nitrate-like compounds can be measured in this experimental model as a drug-induced increase in coronary flow.

In the case of an isolated, striking rat heart, coronary artery resistance was chosen as the parameter indicating the nitrate effect. A rat heart weighing about 1 gram was flushed through the left atrium with a plasma-like solution containing nutrients and saturated with oxygen. Left ventricle against a certain pressure in the aorta of the pump-Pasi solution. According to physiological conditions, some of this solution flowed through the coronary arteries to service the heart itself. When the work done by the heart is constant, this proportion, from which the resistance of the crown can be calculated, remains unchanged. The addition of nitrate or another coronary vasodilator has this depressant effect. Thus, when organic nitrate was introduced into the heart at a concentrated concentration, after 20 minutes, after the decrease observed at the beginning of the resistance, the effect was found to be partially attenuated. These substances also had a coronary dilating effect in this experimental model, but were not associated with a decrease in effect. After another 60 minutes, the decrease in crown resistance was still at its highest. The substances tested were compared to nitroglycerins in equimolar amounts (10 -M). Continuous infusion of nitroglycerin resulted in a rapid increase in coronary flow by 7.6 ± 1.89 ml at 11 μl / min * gww (± SD). Flow. decreased by 55.9% over 20 minutes. As the rinse continued, the effect of nitroglycerin remained unchanged. The new nitrates also had a coronary flow-increasing effect in this experimental model, but only a very small decrease. This result indicates that the described new compounds do not have a tolerance behavior similar to traditional nitrates.

19 95569

table 1

Effect of new organic nitrates on crown flow compared to nitroglycerin in the case of separately rinsed rat cores. X ± SEM, n = 7.

Crest flow Maximum increase, decrease,

m17mx n tgww X

100 μΜ nitroglycerin 7.6 ± 0.71 56.0 100 μΜ N- (3-nitrate light-6.6 ± 0.88 5.2 yl) cysteine ethyl ester 100 μΜ N- (3-nitrate light-8.3 ± 0.92 (7.0 yl) -methionine ethyl ester ± SEM = standard deviation of the mean n = number of standard deviations

Finally, the effect of N- (3-nitrate pivaloyl) -cysteine ethyl ester (Nitrato-Piv-Cy-Et) on the guinea pig heart was investigated. Nitrato-Piv-Cy-Et results in an increase in coronary flow in the Working Heart test (using a guinea pig heart) depending on the concentration, even at very low doses. The flow increases with a concentration of Nitrato-Piv-Cy-Et of 7 in only 380 pg per liter of per-fusion solution, corresponding to a concentration of 1.3 pmol / l. The corresponding concentration in the case of glycerol trinitrate (GTN) is 5 mg / l, ie more than 12 times higher. Thus, the vascular activity associated with Nitrato-Piv-Cy-Et is particularly high. A decrease in the coronary vasodilatory effect as evidenced by the development of tolerance could not be observed during an hour-long serum perfusion at any dose level. From this it can be concluded that Nitrato — Piv — Cy — You do not cause vascular tolerance like GTN.

Nitrato-Piv-Cy — Et, in the case of isolated guanylate cyclase, results in concentration-dependent activation of the enzyme, corresponding to increased cGMP formation per unit time (compare figures). A special feature of this compound compared to conventional organic nitro compounds is that activation in vitro in 95569 also occurs in the absence of cysteine. At the same time, this explains the observation that Nitrato — Piv — Cy — Et and chemical compounds, for example, do not cause any tolerance in the so-called “Working Heart Experiment,” which is of particular practical importance when using these compounds clinically for long periods of time. 50 V. of the maximum activity (ED-, o>, is about 200 pmol / l. For comparison, this value in the case of GTN (in the presence of 5 mmol / l cysteine) is about 80 pmol / l.

Claims (8)

1. A process for the preparation of organic nitrate compounds for the host of heart disease and their pharmaceutically useful salts having the following general formula: R 2 R 2 R 2 which R is hydroxy, lower alkoxy or amino; R 1 is hydrogen or an alkyl containing 1-6 carbon atoms; R 2 is hydrogen or lower alkyl; R 3 is hydrogen or lower alkyl, R 1 is hydrogen or lower alkyl, R 2 is mercaptomethyl, mercaptoethyl, methylthioethyl, its S-acyl derivatives, especially S-acetyl, S-propionyl, S-butyryl, S-capronyl, S caprylic, S-isobutyryl, S-pivaloyl or S-benzoyl; R 2 and R 2 may be bonded together to form thiolactone; m carried the value 0-10; characterized in that these compounds are prepared in a manner known per se by condensing the corresponding nitrate fatty acids or reactive derivatives thereof with amino acid or an amino group and / or by optionally acylating the alkane-capacitor group in the following reaction steps or by alkylating a side chain. Process according to claim 1, characterized in that the compounds in which the chain contains 2-6 carbon atoms in the nitrato fatty acid component are prepared as straight-chain, branch-chain,; racemic or optical isomers. Process according to claims 1 and 2, characterized in that the amino acids are cysteine, methionine or homocysteine. .1 µm in mx i> i t · Method according to claims 1-3, characterized in that 2. the amino acids have a stereochemical L form. 95569 5. A process according to claims 1-4, characterized in that the amino acids cysteine and / or methionine are in the form of their methyl, ethyl or propyl ester. Process according to claims 1-5, characterized in that cysteine is esterified in its SH group with alkanecarboxylic acids, whose chain has a length of 2-8 carbon atoms. Process according to claims 1-6, characterized in that the compounds prepared have the following chemical formulas: N- (2-nitratoacetyl) cysteine ethyl ester N- (2-nitratoacetyl) -S-acetyl-cysteine ethyl ester N- (2-nitratoacetyl) - S-propionyl cysteine ethyl ester N- (2-nitratoacetyl) -S-pivaloyl cysteine ethyl ester N- (2-nitratoacetyl) -methionine methyl ester N- (2-nitratopropionyl) cysteine N- (2-nitratopropionyl) cysteine ethyl ester N- (2- nitratopropionyl) methionine ethyl ester N- (2-nitrratobutyryl) cysteine N- (2-nitrratobutyryl) cysteine ethyl ester N- (2-nitratobutyryl) -S-acetyl-cysteine ethyl ester N- (2-nitrratobutyryl) -S-butyryl cysteine ethyl ester N (2-nitratobutyryl) methionine ethyl ester N- (2-nitratoisobutyryl) cysteine N- (2-nitratoisobutyryl) cysteine ethyl ester in 'N- (2-nitratoisobutyryl) -S-benzoyl-cysteine ethyl ester N- (2-nitratoisobutyryl) -S- acetyl-cysteine ethyl ester N- (2-nitratoisobutyryl) -S-pivaloyl-cysteine ethyl ester N- (2-nitratoisobutyryl) -methionine ethyl ester N- (3-nitratobutyryl) cysteine N- (3-nitratobutyryl) cysteine ethyl ester N- (3-nitr atobutyryl) -S-acetyl-cysteine ethyl ester N- (3-nitratobutyryl) -S-propionyl-cysteine ethyl ester N- (3-nitratobutyryl) -methionine ethyl ester N- (3-nitratobutyryl) homocysteine thiolactone N- (2-nitratohexanoyl) cysteine ethyl ester (2-Nitratohexanoyl) -S-propionyl-cysteine ethyl ester N- (3-Nitratohexanoyl) -cysteine ethyl ester 95569 N- (3-Nitratohexanoyl) -methionine methyl ester N- (12-nitratolauroyl) -cysteine N- (12-nitratolauroyl) -cysteine ethyl (12-nitratolauroyl) -S-acetyl-cysteine N- (12-nitratolauroyl) -S-pivaloyl-cysteine. A process for the preparation of organic nitrate compounds for the host of heart disease and their pharmaceutically useful salts of the following chemical formula: N- (3-nitrate topivaloyl) cysteine N- (3-nitrate topivaloyl) cysteine ethyl ester N- (3 nitrate topivaloyl) -cysteine ethyl ester S-carbonate N- (3-nitrate topivaloyl) -S-acetyl cysteine ethyl ester N- (3-nitrate topivaloyl) -S-propionyl cysteine ethyl ester N- (3-nitrate topivaloyl) -S-butyryl cysteine ethyl ester N- nitrate topivaloyl) -S-isobutyryl cysteine ethyl ester N- (3-nitrate topivaloyl) -S-pivaloyl cysteine ethyl ester N- (3-nitrate topivaloyl) -S-benzoyl cysteine ethyl ester N- (3-nitrate topivaloyl) methionine ethyl ester N- (3-nitrate top -methionine N- (3-nitrate topivaloyl) homocysteine thiolactone, characterized in that these compounds are prepared in a manner known per se by condensing the corresponding nitrate fatty acids or reactive derivatives thereof with the amino group of the amino acid and / or by optionally acylating following reaction steps or by a to alkylate a side chain. • ·