SE451839B - PROCEDURE FOR PREPARING KETAL AND TIOKETAL DERIVATIVES OF MERCAPTOACYL PROLINES - Google Patents

Description

\ N N pentyl, etc. The preferred lower alkyl groups have up to 4 carbon atoms and methyl and ethyl are most preferred.

The term "halogen-substituted lower alkyl" refers to the lower alkyl groups described above in which one or more hydrogen atoms are replaced by chlorine, bromine or fluorine, such as trifluoromethyl, pentafluoroethyl, 2,2,2-trichloroethyl, chloromethyl, bromomethyl, etc.

With respect to the mercaptoacyl side chain, the final products are those compounds in which R5 represents hydrogen, m represents 0 or 1 and R represents hydrogen, lower alkyl having 1 to 4 carbon atoms, especially methyl or trifluoromethyl.

Particularly preferred as end products are those compounds of formula I having a mercaptoacyl side chain wherein R 5 represents hydrogen, m represents 1, R 3 represents methyl and the asymmetric carbon atom to which R 3 is attached is in the D-configuration.

Preferred compounds with respect to the substituents on the proline ring are those wherein R 1 and R 2 independently represent alkyl of 1-4 carbon atoms, especially methyl or ethyl.

The most preferred compounds with respect to the substituents on the proline ring are those wherein X 1 and X 2 are the same, especially those wherein X 1 - R 1 and X 2 - R 2 both represent methoxy or ethoxy or wherein X 1 - R 1 and X 2 - R 2 combine to form about ./ “Ä / CIÄY aC-CHZ f Hc-cn, Hc ca, Hc '\ cn 2 1 2 2 2 2 2 1 1 \ a | The compounds of formula I can be obtained by coupling the substituted proline of the formula: HN CH-COOR with an acid or its chemical equivalent such as an acid chloride of the formula: fa RS .___ S: - (C 1 -C 6 CH 2 COOH wherein R 5 'is lower alkanoyl or benzoyl, and removes said group to form a product wherein R is hydrogen and oxidizes said product with iodine to form the bis-symmetrical disulfide product.

This reaction can be effected in the presence of a coupling agent such as dicyclohexylcarbodiimide or the like or the acid can be activated by the formation of its mixed anhydride, symmetrical anhydride, acid halide, active ester or by the use of Woodward reagent K, N-ethoxycarbonyl-2 -ethoxy-1,2-dihydroquinoline or the like. Regarding the acylation methods, compare the method in Methoden der Organischen Chemie (Houben-Weyl), Volume XV, Part II, page 1 and the following (1974).

Preferably the acid halide, especially the acid chloride of formula III is reacted with the acid of formula II.

If the proline of formula II is allowed to react in the ester form, the resulting ester product of formula IV, i.e. R represents alkyl, is converted to the free acid, i.e. R represents hydrogen, in a conventional manner. For example, if R is ethyl, this ester protecting group can be removed by saponification. 451 859 The final product is preferably isolated and purified by crystallization, e.g. by formation of the dicyclohexylamine salt, after which salts are transferred to the free acid form by treatment with an aqueous solution of an acid such as potassium hydrogen sulphate.

The esters in which R represents lower alkyl can be obtained from the carboxylic acid compounds, i.e. wherein R represents hydrogen, according to conventional esterification procedures, e.g. by esterification with a diazoalkane such as diazomethane, a 1-alkyl-3-p-tolyltriazen such as 1-n-butyl-3-p-tolyltriazen or the like.

The disubstituted starting prolines, wherein X 1 - R 1 and X 2 - R 2 are the same, can be obtained by reacting an N-protected keto compound of the formula: (V) wherein Cbz represents carbobenzyloxy, with an alcohol or thiol of the formula: (VI) R - X -H 11i presence of an orthoformate or thioformate of the formula HC (X1-R1) 3 and an acid such as concentrated sulfuric acid or p-toluenesulfonic acid. This reaction can be effected in an inert organic solvent such as benzene, acetic acid, ether, cyclohexane or the like, preferably under heating, e.g. to approximately reflux temperature. Compare Buehler et al., Survey of Organic Syntheses (Wiley & Sons, 1977), vol. 1, p. 516-519. The product of this reaction is the N-protected intermediate of the formula: 4-51 839 _- n 5 (VII) RI Rl I L X I fl C- ../ \ CH.

The N-protected intermediate of formula VII can be treated with one molar equivalent of an alcohol or thiol of formula (VIII) R 2 -X 2 -H according to the conditions for the preparation of the intermediate (IX) described above. RR 1 2 li XX 2 à C f, / \. uzc Cfïz | In Cbz - N f- (lí-COOR H Using a molar excess of the alcohol or thiol of formula VIII, the intermediate Ö - [I> is obtained.

G1 ... x C 'CN \ O _. 6 (X) lfz 1.92 xx \ 2C / 2, / \\ cH aZCI: I 2 Cbz N ___... Fig. H The N - protecting group can then be removed in a conventional manner, for example when both X1 and X2 represents oxygen by hydrolysis in the presence of a palladium-carbon catalyst or when one or both of groups X1 and X2 are sulfur by treatment with HBr and acetic acid to the di-substituted compounds of formula II.

References are also made to the following publications for further harmful methods of preparing starting materials and intermediates: U.S. Pat. Patents 4,046,889, 4,107,776, 4,154,935 and 4,116,962; Can. J. Biochem. & Physiol. volume 37 (1959) page 584; J.A.C.S. Volume 79 (1957) page 189; J. Med. Chem. volume Z1 (1978) page 445; Aus. J. Chem. volume 20 (1967) pp. 1493 - 1509; Buehler et al., Survey of Organic Syntheses (Wiley & Sons, 1977), Volume 1, pages 516-519, Volume 2, pages 461-470; Chem. Pharm. Bull., Tokyo, Volume 26 (1978) pages 2209 and 2217; Can. J. Chem. volume 47 (1969) page 860; J. Amer. Chem. Soc., Volume 80 (1958) p. 6350; Harrison et al., Compendium of Organic Synthetic Methods (Wiley-Interscience, New York, 1971), pp. 449-456; J. Amer. Chem. Soc., Volume 79 (1956) p. 192; Bull. Soc.

Chem., 1965 (8) pages 2253 - 2259; J. Org. Chem. volume 25 (1960) pages 521 - 530. kw 451 859 The methods illustrated therein can be used as general methods for the synthesis of compounds and the separation of isomers which can be used according to the invention described in this application. Further illustrative details appear from the examples, which serve as a model for the presentation of other members of the group.

The compounds of the present invention form base salts with a variety of inorganic or organic bases. The salt-forming ions derived from such bases may be metal ions, e.g. aluminum, alkali metal ions such as sodium or potassium, alkaline earth metal ions such as calcium or magnesium or an amine salt ion of which a number are known for this purpose such as aralkylamines such as dibenzylamine, N, N-dibenzylethylenediamine, lower alkylamines such as methylamine, t-butylamine, procaine , lower alkylpiperidine such as N-ethylpiperidine, cycloalkylamines such as cyclohexylamine or dicyclohexylamine, 1-adamantanamine, benzatin or salts derived from amino acids such as arginine, lysine or the like. HM The physiologically acceptable salts such as the sodium or potassium salts may be used medically as described below and are preferred. These and other salts, which may not necessarily be physiologically acceptable, can be used to isolate or purify a product acceptable for the purposes described below, as illustrated by the dicyclohexylamine salt in the examples. The salts are prepared by reacting the acid form of the compound with an equivalent of the base which adds the desired base ion in a medium in which the salt precipitates or in aqueous medium and subsequent lyophilization. The free acid form can be obtained from the salt according to conventional neutralization techniques, e.g. with potassium bisulfate, hydrochloric acid etc.

The compound of formula I wherein R 5 represents hydrogen, lower alkanoyl or the disulfide type substituent, especially wherein R 5 represents hydrogen can be used as hypotensive agents. They inhibit the transfer of decapeptide angiotensin I to angiotensin II and are therefore useful in relieving angiotensin-related hypertension. 451 859 8 _- p, Effect of the enzyme renin on angiotensinogen, a pseudoglobulin in blood plasma produces angiotensin I. Angiotensin I is transferred by angiotensin-transferring enzyme (ACE) to angiotensin II.

The latter is an active compressor substance that has been reported as a causative agent in various forms of hypertension in various mammalian species, e.g. rats and dogs. The compounds of the present invention interfere with the angiotensinogen -> (renin) -o angiotensin I-9 (ACE) -oangiotensin II sequence by inhibiting the angiotensin-transferring enzyme and reducing or eliminating the formation of the pressor substance angiotensin II.

By administering a composition containing one or a combination of compounds of formula I, angiotensin-dependent hypertension is alleviated in mammalian species suffering therefrom. A single dose or preferably two or four divided daily doses, provided in an amount of about 0.1 to 100 mg per kg of body weight per day, preferably about 1-15 mg per kg of body weight per day is suitable for reducing blood pressure. . The substance is preferably administered orally but by parenteral routes such as subcutaneous, intramuscular, intravenous. . .. ..: '55 nost or intraperitoneally can also be used.

The compounds of the present invention may also be formulated in combination with a diuretic for the treatment of hypertension. A combination product comprising a compound of the present invention and a diuretic may be administered in an effective amount comprising (for a 70 kg mammal) a total daily dose of about 30 to 600 mg, preferably about 30 to 300 mg, of a compound of the present invention. invention and about 15 to 300 mg, preferably about 200 mg of the diuretic to mammalian species in need thereof. Examples of diuretics that can be used in combination with a compound of the present invention are thiazide diuretics, e.g. chlorothiazide, hydrochlorothiazide, flumethiazide, hydroglumethiazide, benzdroflumethiazide, methclothiazide, trichloromethiazide, polythiazide or benstiazide as well as ethacrynic acid, ticrynaphene, chlorthalidone, furosemide, musolimine, bumethanid, triamone and the pyramids, aminothenone and the triamterene and the aminates, The compounds of formal I can be formulated for use in reducing blood pressure in compositions such as tablets, capsules or in elixirs for oral administration or in sterile solutions or suspensions for parenteral administration.

Approximately 10 to 500 mg of a compound or mixture of compounds of formula I is incorporated into a physiologically acceptable vehicle, carrier, excipient, binder, preservative, stabilizer, flavoring agent, etc. in a unit dosage form suitable for accepted pharmaceutical practice. The amount of active substance in these compositions or preparations is such that a suitable dose within the range indicated will be obtained.

The invention is further illustrated by the following examples in which the temperatures refer to degrees Celsius.

Example 1 [7 (S) (35) 7 '/ 3- (Acetylthio) -2-methyl-1-oxooronyl] -4,4-dinxin-7 azaziro [4.4] nonane-8-carboxylic acid a) N-carbobenzyloxy -4-hydroxy-L-proline 26.5 g (0.20 mol) of 4-hydroxy-L-proline and 32.8 ml (0.23 mol) of benzyl chloroformate are reacted in 200 ml of water and 100 ml of acetone in the presence of 20 g (0.02 mol) of potassium bicarbonate and 69.2 g (0.50 mol) of potassium carbonate and work up with 90 ml of concentrated hydrochloric acid as described in Can. J. Biochem. & Physiol, Volume 37 (1959) page 584 and gives N-carbobenzyloxy-4-hydroxy-L-proline. This product is reacted with cyclohexylamine to give the cyclohexylamine salt in a yield of 69 g, mp 193-195 °. The salt (34 g) is neutralized with N-hydrochloric acid to give 27 g of the free acid as colorless glass [a] 26 O D -70, (c, 1% in chloroform). b) N-Carbobenzyloxy-4-keto-L-proline 21.5 g (0.8 l mol) of N-carbobenzyloxy-4-hydroxy-L-proline are oxidized in 1.2 liters of acetone with 83 ml of 8N chromic acid in sulfuric acid as described in JACS volume 79 (1957) page 189. To facilitate the subsequent filtration of chromium salts, 30 g of Celite (diatomaceous earth) was added to the acetone solution before the introduction of the oxidizing agent. An air stirrer was used.

The reaction mixture is filtered and the acetone filtrate is concentrated to about 300 ml before dilution with 1 liter of chloroform. The solution is washed with 300 ml of saturated sodium chloride (four times), dried (MgSO 4), filtered and the solvent is evaporated to give N-carbobenzyloxy-4-L-proline (22.8 g) which is crystallized from ether (50 ml) -hexane (150 ml) to give 17.2 g (81%) of the product, m.p. 99 DEG-1010 DEG, [.alpha.] D @ 20 + 17 DEG (C, 1% in chloroform). 11 c) N-Carbobenzyloxy-4,4-ethylenedioxy-L-proline A stirred mixture of 12.8 g (0.049 mol) of N-carbobenzyloxy-4-keto-L-proline, 53 ml (0.095 mol) of ethylene glycol and 0, 35 g of p-toluenesulfonic acid - H 2 O in 1.31 liters of benzene are heated and the resulting solution is refluxed for 7 hours (water formed is collected in a Dean-Stark apparatus). After standing overnight at room temperature, the lower glycol layer is separated and the benzene solution is washed with 150 ml of saturated sodium chloride, dried (MgSO 4) and the solvent is evaporated to give 14.6 g of N-carbobenzyloxy-4,4-ethylenedioxy-L -proline as a syrup-like residue. The latter is dissolved in 60 ml of ethanol, filtered, treated with 5 g of cyclohexylamine and diluted with ether. Upon grafting and tearing, the crystalline cyclohexylamine salt is separated; weight after cooling overnight, 9.0 g, m.p. 179 DEG-180 DEG (p. 173 °). The material is recrystallized from acetonitrile, melting point isz - 1840 (p. 179 °), [α] 6 -21 ° (C, 1% 1 EtOH). 8.4 g of the cyclohexylamine salt are suspended in 40 ml of ethyl acetate, stirred, cooled and treated with 40 ml of 1N hydrochloric acid. The layers are separated, the aqueous phase is extracted with additional ethyl acetate (3 x 40 ml), the combined organic layers are dried (MgSO 4) and the solvent is evaporated, finally at 0.2 mm. The syrup-like residue, which begins to crystallize, is triturated under ether and the ether evaporates to give 6.4 g (42%) of almost colorless N-carbobenzyloxy-4,4-ethylenedioxy-L-proline, melting point lol - 10 ° (S. 9s °) [α] 25 D -34 ° (C, 1% 1 cac13>. d) 4,4-ethylenedioxy-L-proline A solution of 3.2 g (0,0104 mol) of N-carbobenzyloxy-4,4-ethylenedioxy-L -proline in 100 ml of methanol-water (2: 1) is treated with 1g \ 5% palladium-carbon and shaken on a Parr hydrogenator for 6 hours. The catalyst is filtered off under nitrogen, washed with methanol and the combined filtrates are evaporated, finally at 0.1 to 0.2 mm to give 1.7 g (94%) of a colorless solid, 4,4-ethylenedioxy-L -proline; melting point 245 - 2470 (decomposition), [α] D 6 -32 ° (C, o, s% 1 1 = 1 meon-H 2 O). e) [7 (S), 8S] -7- [3- (acetylthio) -2-methyl-1-oxopropyl] -1,4-dioxy-7-azaspiro [4,4] nonane-8-carboxylic acid A stirred solution of 3.2 g of 4,4-ethylenedioxy-L-proline (0.0185 mol) in 50 ml of water is cooled to 50 and treated portionwise with solid sodium carbonate to pH 8.5. With continued stirring and cooling, a solution of 3.7 g (0.020 mol) of D-3-acetylthio-2-methylpropanoyl chloride in 5 ml of ether is added portionwise while maintaining the pH at 8.5 with 25% sodium carbonate solution. (approximately 14 ml). After 1 l / 4 hour, the solution is treated with 50 ml of ethyl acetate, stirred, cooled, thoroughly acidified with hydrochloric acid (Izl) to pH 2.0, saturated with sodium chloride and the layers separated. The aqueous phase is extracted with additional ethyl acetate (3 x 50 ml), the combined organic layers are dried (MgSO 4) and the solvent is finally evaporated at 0.2 mm. N The solid residue is triturated under ether and the evaporation is repeated to give 5.9 g (10%) [7 (S), 8S] -7- [3- (acetylthio) -2-methyl-1-oxopropyl] -1 , 4-dioxo-7-azaspiro [4,4] nonane-8-carboxylic acid; melting point 108 - lllo.

The product is converted into dicyclohexylamine salts with 3.4 g of dicyclohexylamine in 70 ml of ethyl acetate. Upon seeding and grating, the crystalline salt precipitates and is recrystallized from 95 ml of acetonitrile; yield 6.7 g, mp 187-19 ° (S. 1a4 °), [α] -5 -59 ° (C, 1% 1 Eton).

The dicyclohexylamine salt is transferred to the free acid by suspending in ethyl acetate and treating with 75 ml of 10% potassium bisulfate and stirring until two layers are obtained. After separation, the aqueous phase is extracted with ethyl acetate (4 x 75 ml), the organic layers are combined, dried (MgSO 4) and the solvent is evaporated to give 4.1 g of colorless [7 (S), 8S] -7 ¥ [3- (acetyl). thio) -2-methyl-1-oxopropyl] -1,4-dioxo-7-azaspiro [4,4] nonane-8-carboxylic acid, m.p. 120-1220 (p. 117), [d] h- G1 _A CO LN \ O (C, 1% in EtOH).

Example 2 [7 (S) -8S] -7- (3-mercapto-2-methyl-1-oxopropyl) -1,4-dioxo-7-azaspiro [4.4] nonane-8-carboxylic acid Argon is passed through a cold solution of 8.5 ml of concentrated ammonium hydroxide in 20 ml of water. 4.0 g (0.013 mol) [7 (S), 8S] - 7- [3- (acetylthio) -2-methyl-1-oxopropyl] -1,4-dioxo-7-azaspiro- [4, 4] Nonane-8-carboxylic acid from Example 1e is then added and the mixture is stirred on an ice bath for a few minutes and then at room temperature under argon for 2 hours. The solution is treated with 30 ml of ethyl acetate, cooled, stirred and acidified with 16 ml of hydrochloric acid (1: 1). The layers are separated, the aqueous phase is extracted with an additional 30 ml of ethyl acetate (twice), the ethyl acetate extracts are combined, dried (MgSO 4) and the solvent is evaporated to give [7 (S), 8S] -7- (3-mercapto-2-methyl-1). oxopropyl) -1,4-dioxo-7-azaspiro [4,4] nonane-8-carboxylic acid as solid residue. The product is triturated under ether and evaporation is repeated. The product is then decomposed with 30 ml of hexane, cooled for 1 hour, filtered under argon and dried in vacuo to give 2.7 g of a colorless solid [7 (S), 8S] -7- (3-mercapto-2-methyl-1 - oxopropyl) -1,4-dioxo-7-azaspiroI4,4] nonane-8-carboxylic acid, m.p. 131 DEG-133 DEG (p. 125 DEG.), [.alpha.

Example 3 (S) -1 - [(3-acetylthio) -2-methyl-1-oxopropyl] -4,4-dimethoxy-L-proline a) N-carbobenzyloxy-4,4-dimethoxy-L-proline, methyl ester A stirred solution of 7.8 g (0.03 mol) of N-carbobenzyloxy-4-keto-L-proline from Example 1 in 60 ml of methanol is treated with 96 ml of trimethyl orthoformate, followed by 0.6 ml of concentrated sulfuric acid. and then allowed to stand overnight at room temperature.

The pale yellow solution is stirred, treated with 1.0 g of potassium carbonate, followed by 30 ml of water and the majority of the solvent is removed on a rotary evaporator to give a syrup-like residue which is shaken with 30 ml of water and 30 ml of chloroform. After separation of the layers, the aqueous phase is extracted with additional chloroform (3 x 30 ml) and the combined organic layers are washed with 45 ml of saturated sodium chloride solution and dried (MgSO 4). Evaporation of the solvent gives 8.4 g (88%) of N-carbobenzyloxy-4,4-dimethoxy-L-proline, methyl ester. b) N-Carbobenzyloxy-4,4-dimethoxy-L-proline The ester (8.4 g, 0.026 mol) from part a is dissolved in 80 ml of methanol, treated dropwise at -1 to 40 with 18 ml (0.036 mol) of 2N sodium hydroxide at Oo il hour and at room temperature overnight. After removing about half of the solvent on a rotary evaporator, the solution is diluted with 150 ml of water, washed with 100 ml of ether (the washing liquid is discarded), acidified under cooling with 63 ml of 1: 1 hydrochloric acid to pH 2 and extracted with ethyl acetate (4 x 750 ml). The combined extracts are washed with 50 ml of saturated sodium chloride solution, dried (MgSO 4) and the solvent is evaporated to give 8.0 g of a light yellow viscous oil.

The oil is dissolved in 35 ml of ethanol, treated with 3.0 g of cyclohexylamine in 10 ml of ethanol and diluted to 500 ml with ether. Upon grafting and rubbing, the crystalline N-carbobenzyloxy-4,4-dimethoxy-L-proline cyclohexylamine salt is separated; weight after cooling overnight 7.0 g, melting point l57 - 1590 (s, l5l) [d] š6 -340 (c, 1% in EtOH). This material is recrystallized from 100 ml of acetonitrile to give the salt as a colorless solid, m.p. 158 DEG-100 DEG (s, 1.4 DEG), mesh -33 DEG (c, 1% in mare).

The N-carbobenzyloxy-4,4-dimethoxy-L-proline cyclohexylamine salt is suspended in 40 ml of ethyl acetate, stirred and treated with 1 ml of 1N hydrochloric acid. When two clear layers are obtained, they are separated, the aqueous phase is extracted with additional ethyl acetate (3 x 40 ml), the combined organic layers are dried (MgSO 4) and the solvent is evaporated, finally at 0.2 mm and 400 to give 7.2 g (70 g). %) N-carbobenzyloxy-4,4-dimethoxy-L-proline as a light yellow viscous syrup. c) 4,4-Dimethoxy-L-proline A solution of N-carbobenzyloxy-4,4-dimethoxy-L-proline (72 g, 0.022 mol) in 20 ml of methanol-water (2: 1) is treated with 2.3 g% palladium-carbon and shaken on a Parr hydrogenator for 6 hours. The catalyst is filtered off under nitrogen, washed with methanol and the combined filtrates are evaporated, finally at 0.1 - 0.2 mm to give a partially crystalline residue. This residue is taken up in ZOO ml of methanol and evaporation is repeated.

When the solid is triturated under ether (evaporation is repeated), 3.6 g (95%) of an almost colorless 4,4-dimethoxy-L-protein are obtained, m.p. 192 DEG-194 DEG (sonication); [α] 25 D -47 ° (C, 1% in MGOH).

A sample crystallized from methanol-ether is colorless and melts via 197 DEG-19 DEG (sonication); {α] D6 -49 ° <0.1% 1 MeOH). d) (S) -1- [3- (acetylthio) -2-methyl-1-oxopropyl] -4,4-dimethoxy-L-proline A stirred solution of 3.3 g (0.019 mol) 4.4 -dimethoxy-L-proline in 50 ml of water is cooled to 50 and transferred to pH 8.5 by the addition of 25% sodium carbonate solution (w / v). Then, with continued stirring and cooling, a solution of 3.8 g (0.02 l mol) of D-3-acetylthio-2-methylpropanoyl chloride in 5 ml of ether is added portionwise while maintaining the pH at 7.5 - 8.5 by dropwise addition of 25% sodium carbonate solution. When the pH has stabilized at 8.2 - 8.4 (after about minutes), stirring and cooling continue for a total of 1 hour. The solution is then washed with 50 ml of ethyl acetate (the wash is discarded, layered with 50 ml of ethyl acetate, cooled, stirred, thoroughly acidified with 1: 1 hydrochloric acid to pH 2.0, saturated with sodium chloride and the layers separated. with additional ethyl acetate (3 x 50 ml), the combined organic layers are dried (MgSO 4) and the solvent is finally evaporated at 0.2 mm to give 6.7 g of syrupy product, which is treated in 70 ml of ethyl acetate with 3.9 g of dicyclohexylamine. and gives 6.5 g of colorless (S) -1- [3- (acetylthio) -2-methyl-1-oxopropyl] -4,4-dimethoxy-L-prolindicyclohexylamine salt in crops (3.1 g and 3, 4 g), m.p. 158 DEG-110 DEG (s, 14 DEG C.), [.alpha.] D @ 20 -71 DEG (C, 1% in EtOH).

After recrystallization from 20 ml of hot ethyl acetate - 60 ml of hexane, the colorless solid salt weighs 6.0 g, m.p.

The dicyclohexylamine salt is converted to the free acid by suspending 0 g in 50 ml of ethyl acetate, cooling and treating with 60 ml of 10% potassium bisulfate solution to give two clear layers.

After separation, the aqueous phase is extracted with ethyl acetate (3 x 50 ml), the combined organic layers are dried (MgSO 4) and the solvent is evaporated, finally at 0.1 - 0.2 mm and 450 to give 4.1 g (69%) (S). -1- [3- (acetylthio) -2-methyl-1-oxopropyl] -4,4-dimethoxy-L-proline as a viscous, almost glass-like material [α] -5 -112 ° (C, 1% 1 mare).

Example gel 4 (S) -1- (3-mercapto-2-methyl-1-oxopropyl) -4,4-dimethoxy-L-proline Argon is passed through a cold solution of 8.5 ml of concentrated ammonium hydroxide in 20 ml of water in 0.25 hours. The latter is then added under cooling and under an argon atmosphere to 4.1 g (0.013 mol) of (S) -1- [3- (acetylthio) -2-methyl-1-oxopropyl] -4,4-dimethoxy-L- proline and the mixture is stirred in an ice bath until a light yellow solution is obtained (about 15 minutes). Stirring under argon is continued at room temperature for a further 2 hours, then the solution is extracted with 30 ml of ethyl acetate (this and subsequent processes are carried out as much as possible under an argon atmosphere). The aqueous layer is cooled, stirred, layered with 30 ml of ethyl acetate and acidified portionwise with about 16 ml of 1: 1 hydrochloric acid. The layers are separated, the aqueous phase is extracted with additional ethyl acetate (3 x 30 ml), the combined ethyl acetate layers are dried (MgSO 4) and the solvent is evaporated to give 3.5 g (100%) of (S) -1- (3-mercapto). 2-methyl-1-oxopropyl) -4,4-dimethoxy-L-proline as a colorless viscous syrup, [α] -5 -72 ° (C, 1% 1 mare).

The latter (3.4 g) is decomposed with 20 ml of ethyl acetate, grated, diluted with 30 ml of hexane and cooled to give a colorless solid weighing 2.6 g, m.p. 108 DEG-110 DEG, [.alpha.] D @ 25 -770 ( c, 1% in EtOH).

Example 5 (S) -1- [3- (acetylthio) -2-methyl-1-oxopropyl] -4,4-diethoxy-L-proline a) N-carbobenzyloxy-4,4-diethoxy-L-proline, ethyl ester According to the procedure of Example 3 (a) but using triethyl orthoformate instead of the trimethyl orthoformate and ethanol instead of methanol, 10.8 g of N-carbobenzyloxy-4,4-diethoxy-L-proline ethyl ester were obtained as a yellow oil. b) N-Carbobenzyloxy-4,4-diethoxy-L-proline The crude ester from part (a) (10.8 g, 0.03 mol) is saponified with 70 ml of 1N sodium hydroxide according to the procedure of Example 4 (b), ml of ethanol is added in 10 ml portions to a solution to give 10.5 g of a yellow viscous oil. This oil is dissolved in 100 ml of ether and treated with 3.0 g of cyclohexylamine. Upon grafting and tearing, 8.3 g of the crystalline N-carbobenzyloxy-4,4-diethoxy-L-prolinccyclohexylamine salt are separated; melting point 123 - 12e ° (S. 114 °) [α126 -32 ° (C, 1% in ethanol).

D This material is recrystallized from 20 ml of acetonitrile to give - ~ 18 7.0 g of the salt as a colorless solid; mp 125-1280 (S. 11s °> [alsö -31 ° (C, 1% 1 ethanol).

The N-carbobenzyloxy-4,4-diethoxy-L-proline cyclohexylamine salt is suspended in 40 ml of ethyl acetate, stirred and treated with 20 ml of 1N hydrochloric acid. The layers are separated and the aqueous phase is extracted with additional ethyl acetate (3 x 40 ml), the organic layers are combined, dried (MgSO 4) and the solvent is evaporated to give 5.6 g (56%) of N-carbobenzyloxy-4,4-diethoxy-L-proline as bright yellow oil. c) 4,4-Diethoxy-L-proline A solution of N-carbobenzyloxy-4,4-diethoxy-L-proline (5.6 g, 0.017 mol) in 108 ml of 2: 1 ethanol-water is treated with 2 g of 5 % palladium-carbon catalyst and shake under 3 atmospheres of hydrogen for 6 hours. The crude partially solid product is first triturated under ethanol, then ether and evaporation is repeated each time to give 3 g (91%) of almost colorless solid 4,4-diethoxy-L-proline; melting point 172 - 1740 (decomposition9); the precursor of gradual labeling and sintering [a] š6 -4o ° (C, 1% 1 methanol). (m6 Analysis Calculated for C 9 H 17 NO 4: 0.25 H 2 O: C, 52.03; H, 8.49; N, 6.74 Found: C, 52.22; H, 8.59; N, 6.69 d) (S) -1- [3- (acetylthio) -2-methyl-1-oxopropyl] -4,4-diethoxy-L-Broline 2.9 g (0.014 mol) 4,4-diethoxy-L-proline from part (c) and 3 g (0.017 mol) of D-3-acetylthio-2-methylpropionyl chloride dissolved in 3.5 ml of ether are reacted with 35 ml of water in the presence of sodium carbonate according to the procedure of Example 3 (d). and gives 5.4 g of light yellow viscous oil. This oily product is treated in 40 ml of ethyl acetate with 2.6 g of dicyclohexylamine and diluted with 60 ml of hexane to give two harvests of 4.9 g of (S) -1 - [(3-acetylthio) -2-methyl-1-oxypropyl]. -4,4-diethoxy-L-prolindicyclohexylamine salt, [:> LH-J-CO LN \ O melting point 135-380 (p. 1320). After recrystallization from 15 ml of hot ethyl acetate-45 ml of hexane, the colorless solid salt weighs 4.2 g; mp 138 - 14 ° (s 135 °), [u6š6 -63 ° (c, 1% 1 ethanol).

Analysis Calculated for Cl5H25NO6S. Cl 2 H 23 N: C, 61.33; H, 9.15; N, 5.30; S, 6.06 Found: C, 61.48; H, 9.55; N, 5.25; S, 5.9 L The dicyclohexylamine salt is transferred to the free acid by suspending 4.2 g in 40 ml of ethyl acetate, cooling and treating with 40 ml of 10% potassium bisulfate solution to give two layers. After separation, the aqueous phase is extracted with ethyl acetate (3 x 50 ml), the combined organic layers are dried (MgSO 4) and the solvent is evaporated to give 3.0 g (61%) of (S) -1-I3- (acetylthio) -2- methyl-1-oxopropyl] -4,4-diethoxy-L-proline as a light yellow viscous syrup. Example 6 (S) -4,4-Diethoxy-1- (3-mercapto-2-methyl-1-oxopropyl) -L-proline Argon is passed through a cold solution of 5.5 ml of concentrated ammonium hydroxide in 13 ml of water for 0.25 hours. The latter is then added under cooling under an argon atmosphere to 3.0 g (0.0086 mol) of (S) -1- [3- (acetylthio) -2-methyl-1-oxopropyl] -4,4-diethoxy-L-proline and the mixture is worked up as described in Example 4 to give 2.4 g (92%) of (S) -4,4-diethoxy-1- (3-mercapto-2-methyl-1-oxopropyl) -L-proline as almost colorless viscous syrup [a1š6 -64 ° (C, 1% 1 ethanol).

Analysis Calculated for C 13 H 23 NO 5. 0.25 H 2 O: C, 50.38; H, 7.64; N, 4.52; S, 10.35 Found: C, 50.68; H, 7.96; N, 4.78; S, 10.07 45? Example 7 [2 (S), 3S] -2- [3- (acetylthio) -2-methyl-1-oxopropyl] -6,10-dioxo-2-azaspiro [4,5] decane-3-carboxylic acid a ) N-Carbobenzyloxy-4,4-trimethylenedioxy-L-proline Interaction of 8.2 g (0.03l mol) of N-carbobenzyloxy-4-keto-L-proline and 45 ml (0.62 mol) 1,3- propanediol in 450 ml of benzene in the presence of 500 mg of p-toluenesulfonic acid gives 12.3 g of crude viscous ester product. This product is saponified with 70 ml of 1N sodium hydroxide to give 10.6 g of crude N-carbobenzyloxy-4,4-trimethylenedioxy-L-proline as a yellow oil. The latter is dissolved in 40 ml of ethanol - 400 ml of ether and treated with 3.2 g of cyclohexylamine to give 10.1 g of N-carbobenzyloxy-4,4-trimethylenedioxy-L-proline, cyclonexylamine salt; mp 163-1es ° (S. 160 °), [α] D 6 -270 (c, 1% in ethanol). Crystallization of 9.8 g of the salt from 300 ml of acetonitrile gives 9.5 g of a colorless solid cyclohexylamine salt; melting point 165 - 1s7 ° (s. 1sz °> [oqå-r ”-27 ° (c, 1% in ethanol).

The cyclohexylamine salt (9.0 g) is suspended in 40 ml of ethyl acetate, stirred and cooled and treated with 45 ml of 1N hydrochloric acid. The layers are separated, the aqueous phase is extracted with additional ethyl acetate (3 x 40 ml), the combined organic layers are dried (MgSO 4) and the solvent is evaporated to give 7.1 g (75%) of glass-like N-carbobenzyloxy-4.4 -trimethylenedioxy-L-proline. b) 4,4-Trimethylenedioxy-L-proline A solution of 7.1 g (0.022 mol) of N-carbobenzyloxy-4,4-trimethylenedioxy-L-proline in 200 ml of 2: 1 methanol-water is hydrogenated in the presence of 2 g of 5% palladium-carbon catalyst to give 3.8 g (93%) of almost colorless 4,4-trimethylenedioxy-L-proline; melting point 234 - 2360 (decomposition); the precedence of gradual darkening and sintering; [α] D -360 (c, 0.5% in 1: 1 methanol-water). 4> LH .A CD CN \ D 21 Analysis Calculated for C 8 H 13 NO 4: C, 51.33; H, 7.00; N, 7.48 Found: C, 51.42; H, 7.11; N, 7.40 c) [2 (S), 3S] -2- [3- (acetylthio) -2-methyl-1-oxopropyl] -6,10-dioxo-2-azaspiro [4,5] decane 3-Carboxylic acid 4,4-trimethylenedioxy-L-proline (3.7 g, 0.02 mol) is acylated with 4.0 g (0.022 mol) of D-3-acetylthio-2-methylpropionyl in 50 ml of water in the presence of sodium carbonate according to the procedure of Example 1 (e) to give 7.3 g of glass-like crude product.

The product is converted to its cyclohexylamine salt with 3.6 g of dicyclohexylamine in 70 ml of ethyl acetate. Upon grafting and grating, the crystalline salt precipitates to give 7.5 g of dicyclohexyl ore salt; melting point 168 - 11ø ° (s. 166%, mšö -59 ° (s, 1% in ethanol). Recrystallization from 30 ml of acetonitrile gives 6.5 g of color solid; says melting point 169 - 171 °, [sqšs -63 °, (s, 1% in ethanol).

In the W Dicyclohexylamine salt is transferred to the free acid by suspending 6.4 g in 75 ml of ethyl acetate and treating with 75 ml of 10% potassium bisulfate and stirring until two layers are obtained. After separation, the aqueous phase is extracted with ethyl acetate (4 x 75 ml), the organic layers are combined, dried (MgSO 4) and the solvent is evaporated to give 4.3 g (67%) of glass-like [2 (S), 3S] -2- [ 3- (acetylthio) -2-methyl-1-oxopropyl] -6,10-dioxo-2-azaspiro [4,5] decane-3-carboxylic acid.

Example Gel 8 [2 (S), 3S] -2- (Bmercapto-2-methylel-oxopropyl) -6,10-dioxo-2-azaspiro [4,5] decane-3-carboxylic acid [2 (S), 3S] -2- [3- (acetylthio) -2-methyl-1-oxopropyl] -6,10-dioxo-2-azaspiro [4,14] decane-3-carboxylic acid (4.3 g, 0.013 mol) is hydrolyzed with 8 , 5 ml of concentrated ammonia in 20 ml according to the procedure of Example 2 to give 0.9 g of colorless solid product; Ialâs -640 (c, 0.5% in ethanol). An additional 0.8 g of the product is obtained by extracting the aqueous phase with chloroform; lalšs are triturated under ether and the evaporation is repeated to give 1.7 g -660. The two crops are dissolved in chloroform, evaporated, (46%) [2 (S), 3S] -2- (3-mercapto-2-methyl-1-oxopropyl) -6,10-dioxo-2-azaspiro [4, Sldecane-3-carboxylic acid; mp 169 DEG-171 DEG (S. 17 DEG C.), [.alpha.] D @ -1 -71 DEG (C, 1% in methanol).

Analysis Calculated for C 12 H 19 NO 5 S: C, 49.81; H, 6.62; N, 4.84; S, 11.08 Found: C, 49.67; H, 6.67; N, 4.93; S, 11,10 Example 9 [7 (S), 8S] -7- [3- (acetylthio) -2-methyl-1-oxopropyl] -7-aza-1,4-dithiazpiro [4,4] nonane 8-Carboxylic acid a) N-Carbobenzyloxy-4,4-ethylenedithio-L-proline, methyl ester A stirred solution of 3.9 g (0.014 mol) of N-carbobenzyloxy-4-keto-L-proline, methyl ester in 60 ml methylene chloride is treated with 3 ml (0.036 mol) of ethanedithiol, cooled to 80 and treated under argon with 3 ml (0.024 mol) of boron trifluoride etherate. After removing the cooling bath, the pale yellow solution is stirred for a further hour and kept at room temperature overnight. The solution is stirred, treated with several pieces of crushed ice, followed by ml of water. After 30 minutes, the layers are separated and the aqueous phase (50 ml) is extracted with additional methylene chloride (3 x ml). The combined organic layers are washed with 50 mL of saturated sodium chloride solution, dried (MgSO 4) and the solvent removed on a rotary evaporator to give 6 g (10%) of a light yellow oil of N-carbobenzyloxy-4,4-ethylenedithio-L-proline methyl ester. b) N-Carbobenzyloxy-4,4-ethylenedithio-L-proline The methyl ester product from part (a) (7.4 g, about 0.018 mol). CO CN \ O 23 is dissolved in 65 ml of methanol, treated dropwise at -10 to 40 with 14.5 ml (0.029 mol) of 2N sodium hydroxide, kept at 0o for 1 hour and at room temperature overnight. After removing about half of the solvent on a rotary evaporator, the solution is diluted with 125 ml of water, washed with ether (the washing liquid is discarded), acidified under cooling with 5 ml of 1: 1 hydrochloric acid to pH 2 and extracted with ethyl acetate (4 x 50 ml). The combined extracts are washed with 50 ml of saturated sodium chloride, dried (MgSO 4) and the solvent is evaporated to give 6 g of a light yellow viscous oil. This oil is dissolved in 25 ml of ethanol, treated with 1.8 g of cyclohexylamine in 5 ml of ethanol and diluted to 300 ml with ether. Upon grafting and shredding, the crystalline cyclohexylamine salt separates to give, after cooling overnight, 7 g of N-carbobenzyloxy-4,4-ethylenedithio-L-proline cyclohexylamine salt; melting point 205 - 2070 (p. 2010). Recrystallization from 50 ml of ethanol - 400 ml of ether gives 4.9 g of colorless solid salt; melting point 207 - 2o9 ° (s. 2o1 °), [cqšs -1s ° (c, 1% in chloroform). The cyclohexylamine salt (4.8 g) is suspended in 25 ml of ethyl acetate, stirred and treated with 25 ml of 1N hydrochloric acid. When two clear layers are obtained, these are separated, the aqueous phase is extracted with additional ethyl acetate (3 x 25 ml), the combined layers are dried (MgSO 4) and the solvent is evaporated to give 3.8 g (62%) of N-carbobenzyloxy-4,4-ethylenedithio L-proline as a bright yellow viscous syrup. c) 4,4-ethylenedithio-L-proline, hydrobromide N-carbobenzyloxy-4,4-ethylenedithio-L-proline (3.7 g, 0.011 mol) is treated with 20 ml of hydrogen bromide in acetic acid (30 - 32%), packed dissolved and stirred magnetically. The mixing is difficult due to the viscosity of the starting material and the latter is broken up as much as possible with a spatula. Meanwhile, the crystalline product begins to separate. Additional amounts of hydrogen bromide in acetic acid are added after 15 minutes (10 ml) and after 25 minutes (5 ml) and stirring is continued for a total of 24 minutes. Ether (250 ml) is added to complete the precipitation of the product and after cooling for 15 minutes the cream is filtered under nitrogen, washed with ether and dried in vacuo to give 2.7 g of 4,4-ethylenedithio-L-proline , hydrobromide; melting point 240 - 2420 (decomposition); sintering and darkening from about 2000; [α] D 6 -400 (c, 0.5% in 1zl chloroform-methanol). d) [7 (S), 8S] -7- [3- (acetylthio) -2-methyl-1-oxopropyl} -7-aza-1,4-dithiaziro [4.4] nonane-8-carboxylic acid One stirred solution of 2.6 g (0.009l mol) of 4,4-ethylenedithio-L-proline, hydrobromide in 25 ml of water is cooled to 50 and transferred to pH 8.2 by the addition of 25% sodium carbonate (w / v). With continued stirring and cooling, a solution of 1.9 g (0.01 mol) of D-3-acetylthio-2-methylpropionyl chloride in 2.5 ml of ether is added portionwise while maintaining at 7.5 to 8 mol. , 2 by dropwise addition of 25% sodium carbonate.

When the pH has stabilized at 8.2 - 8.5 (after about 15 minutes), stirring and cooling continue for a total of 1 hour. The solution is then washed with 25 ml of ethyl acetate (the washing liquid is discarded), layered with 25 ml of ethyl acetate, cooled, stirred, thoroughly acidified with 1l hydrochloric acid to pH 2.0, saturated with sodium chloride and the layers separated. The aqueous phase is extracted with additional ethyl acetate (3 x 25 ml), the combined organic layers are dried (MgSO 4) and the solvent is finally evaporated at 0.2 mm to give 2.6 g of syrupy product which begins to crystallize. The latter is treated in 30 ml of ethyl acetate with 1.5 g of dicyclohexylamine to give 3.0 g of colorless dicyclohexylamine salt; melting point 176 - 17 ° ° (s. 17o °); gull -5s ° (c, 1% in ethanol). This material is ground in a mortar under 15 ml of acetonitrile, cooled for 1 hour, filtered, washed with 5 ml of cold acetonitrile and ether and dried to give 2.9 g of dicyclohexylamine salt; mp 177 - 179 ° (s. 172%; [oqåö -se ° (e, 1% in ethanol). 4> ~ (II _ .. å Ci) C vd \ O Analysis Calculated for Cl3H19NO4S _ Cl2H23N: C , 56.56; H, 7.98; N, 5.28; S, 18, 12 Found: C, 56.21; H, 8.18; N, 5.05; S, 18.00 The above dicyclohexylamine salt Transfer to the free acid by suspending 2.8 g of 30 ml of ethyl acetate, cooling and treating with 30 ml of 10% potassium bisulfate to give two clear layers.After separation, the aqueous phase is extracted with ethyl acetate (3 x 30 ml), the combined the organic layers are dried (MgSO 4) and the solvent is evaporated, finally at 0.1 - 0.2 mm and 450 to give 2.0 g (63%) of a colorfully solid [7 (s), ss1-7- [3- (acetylthio) -2-methyl-1-oxopropyl] -7-aza-1,4-dithiazpiro [4,41-nonaag-8-carboxylic acid, m.p. 125 DEG-1260 DEG (p. 1220); % in ethanol).

Example 10 [7 (S), 8S] -7- (3-mercapto-2-methyl-1-oxopropyl) -7-aza-1,4-dithispiro [4,4] nonane-8-carbogyl acid Argon is allowed to pass through a cold solution of 3.5 ml of concentrated ammonia in 8.5 ml of water for 15 minutes. The latter is then added under cooling and under an argon atmosphere to 1.79 (0.0054 mol) [7 (S), 8S] -7- [3- (acetylthio) -2-methyl-1-oxopropyl] -7-aza-1,4-dithiazpiro [4,4] nonane-8-carboxylic acid and the mixture is stirred in an ice bath until a solution is obtained. Stirring under argon is continued at room temperature for a further 2 hours, after which the solution is extracted with 15 ml of ethyl acetate under an argon atmosphere. The aqueous layer is cooled, stirred, layered with 15 ml of ethyl acetate and acidified portionwise with about 6.5 ml of 1: 1 hydrochloric acid. The layers are separated, the aqueous phase is extracted with additional ethyl acetate (3 x 1S ml), the combined acetate layers are dried (MQSO 4) and the solvent is evaporated to give a glass-like residue which solidifies on decomposition under ether. The evaporation is repeated and the colorless product is suspended in 30 ml of hexane, filtered and dried in vacuo to give 1.4 g (84%) of [7 (S), 8S] -7- (3-mercapto-2-methyl-1-451). 859 ..- n 26 oxopropyl) -7-aza-1,4-dithiazpiro [4,4] nonane-8-carboxylic acid; melting point 116 - 11s ° (s. 1os °); [α] 25 D -44 ° (c, 1% in ethanol).

Analysis Calculated for C 11 H 17 NO 3 S 3: C, 42.97; H, 5.57; N, 4.56; S, 31.29; SH, MI% Rnmætz C, 42.70; H, 5.71; N, 4.54; S, 31.16; SH, MI% Exemgel 11 [2 (S), 3S] -2- (3-mercapto-2-methyl-1-oxopropyl) -6,10-dithia-2-azaspiro [4,5] decane-3-carboxylic acid a) [2 (S), 3S] -2- {3- (acetylthio) -2-methyl-1-oxopropyl] -6,10-dithia-2-azaspiro [4,5] decane-3-carboxylic acid According to the procedure in Example 9 but using 1,3-propanedithiol instead of the ethanedithiol in part (a), [2 (S), 3S] -2- [3- (acetylthio) -2-methyl-1-oxopropyl] -6 10-dithio-2-azaspiro [4,5] decane-3-carboxylic acid. b) [2- (S), 3S] -2- (3-mercapto-2-methyl-1-oxopropyl) -6,10-dithia-2-azaspiro [4,5] decane-3-carboxylic acid The product from part (a) hydrolyzed with concentrated ammonia according to the procedure of Example 10 to give [2 (S), 3S] -2- (3-mercapto-2-methyl-1-oxopropyl) -6,10-dithia-2-azaspiro [4,5] decane-3-carboxylic acid. n: 451 839 27 Exemgel 12 [7 (S), 8S] -7- (3-mercapto-2-methyl-1-oxopropyl) -1-oxo-4-thia-7-azaspiro [4,4] nonan- 8-Carboxylic acid a) [7 (S), 8S] -7- [3- (acetylthio) -2-methyl-1-oxopropyl] -1-oxo-4-thia-7-azaspiro [4.4] nonane- 8-Carboxylic acid According to the procedure of Example 1, but using 2-mercaptoethanol instead of the ethylene glycol in part (c), [7 (S), 8S] -7- [3- (acetylthio) -2-methyl-1 -oxopropyl] -1-oxo-4-thia-7-azaspiro [4,4] nonane-8-carboxylic acid. b) [7 (S), 8S] -7- (3-mercapto-2-methyl-1-oxopropyl) -1-oxo-4-thia-7-azaspiro [4,4] nonane-8-carboxylic acid The product of part (a) is hydrolyzed with concentrated ammonia according to the procedure of Example 2 to give [7 (S), 8S] -7- (3-mercapto-methyl-1-oxopropyl) -1-oxo-4-thia-7-azaspiro [4,4] nonane-8-carboxylic acid.

Example Gel 13 (85) -7- [3- (acetylthio) -2-trifluoromethyl-1-oxypropyl] -1,4-dioxo-7-azaspiro [4.4] nonane-8-carboxylic acid (Isomers A and B) a D, L-3- (acetylthio) -2-trifluoromethylpropionic acid Q-trifluoromethylacrylic acid (10 g, 0.071 mol) (prepared according to the procedure of J. Chem. Soc., 1954, page 371) is cooled in a salt-ice-water bath, The mixture is stirred and treated portionwise with 5.7 ml (0.075 mol) of 97% thiolacetic acid. After the addition, the yellow liquid is stirred in cold for 1 hour, allowed to warm to room temperature and distilled to give 14 g (91%) of D, L- 3 ~ (acetylthio) -2-trifluoromethylpropionic acid as light yellow oil, b.p. 149 - 1530/13 mm. The material solidifies when stored under cold conditions. b) D, L-3- (acetylthio) -2-trifluoromethylpropionyl chloride D, L-3- (acetylthio) -2-trifluoromethylpropionyl acid (7 g, 0.032 mol) is treated with 18 ml (0.25 mol) of redistilled thionyl chloride and the mixture is refluxed for 3 hours. After removing the excess thionyl chloride on a rotary evaporator, the residue is distilled to give 6.8 g of D, L-3- (acetylthio) -2-trifluoromethylpropionyl chloride as pale yellow oil; boiling point ao - 82 ° / 16 m. c) (SS) -7- [3- (acetylthio) -2-trifluoromethyl-1-oxopropyl] -1,4-dioxo-7-azaspiro [4.4] nonan-8 Carboxylic acid (Isomers A and B) 4,4-ethylenedioxy-L-proline (2.4 g, 0.014 mol) is reacted with 3.4 g (0.014 mol) of D, L-3- (acetylthio) -2 trifluoromethylpropionyl chloride in 40 ml of water in the presence of sodium carbonate according to the procedure of Example 1 (e) to give 4.5 g of an almost colorless solid product; melting point 126 - 14s ° (S. 11s °), [a1š5 -34 ° (C, 1% in ethanol).

The mixture of diastereoisomers (4.2 g) is suspended in 45 ml of ether, stirred for 2 hours, cooled for 20 minutes and the undissolved solid is filtered, washed with cold ether and air dried to give 2.7 g of product; melting point 166 - 1720 (p. 1400), [a1š5 -62 ° tel under 25 ml of ether, filtered after 15 minutes, washed with a small amount of ether and air dried again to give 2.1 g of product, melting point l72 - 177 ° (s 1430). After crystallization from 11 ml of boiling isopropanol and cooling overnight, 1.55 g of colorless (85) -7- [3- (acetylthio) -2-trifluoromethyl-1-oxopropyl] -1,4-dioxo-7-azaspiro are obtained. [4,4] nonane-8-carboxylic acid, isomer A; melting point 192 - 194 ° (S. 1s3 °), [α] -5 -3z ° (C, 1% 1 ethanol). A sample is recrystallized from isopropanol; mp 193-195 ° (p. 184 °), [α] D -134 ° (C, 1% 1 ethanol). (c, 1% in ethanol). The material is then ground in the isomer B is obtained by combining the above ether and isopropanol filtrates and removing the solvents under reduced pressure to give 2.2 g of a pale yellow solid; Melting point 108 DEG-109 DEG (5.9 DEG C.> [.alpha.] D @ 20 + 30 DEG C. (C, 1% of ethanol) This material is purified by crystallization from 6 ml of isopropanol to give 1.2 g of an almost colorless solid; Melting point 153 DEG-1.5 DEG. ° (S. 130 °), (@ 1š5 + 40 ° (C, 1% 1 ethanol).

After crystallization from 4 ml of ethyl acetate - 6 ml of hexane, 1,1 g (8S) -7- [3- (acetylthio) -2-trifluoromethyl-1-oxopropyl] -1,4-dioxo-7-azaspiro [4.4] are obtained. nonane-8-carboxylic acid, isomer B; mp 153 - 15s ° (S. 141 °), [e1š5 + 41 ° (C, 1% 1 ethanol).

Example gel 14 (8S) -7- (3-mercapto-2-trifluoromethyl-1-oxopropyl) -1,4-dioxo-7-azaspiro [4.4] nonane-8-carboxylic acid, Isomer A Isomer A product from Example 13 (1.45 g, 0.0039 mol) is hydrolyzed in 2.5 ml of concentrated ammonia in 6 ml of water for 1 hour as described in Example 2 to give 1.25 g (97%) of colorless (8S). ) -7- (3-mercapto-2-trifluoromethyl-1-oxopropyl) -1,4-dioxo-7-azaspiro [4,4] nonane-8-carboxylic acid, isomer A, as a glass-like product, [o] š5 -610 (c, 1% in ethanol). TLC: Rf 0.40 (95: 5: 5 methylene chloride-methanol-acetic acid; vis. SH reagent, PMA and heat).

Analysis Calculated for C 11 H 14 F 3 NO 5 S: C, 40.12; H, 4.28; N, 4.25; S, 9.74; F, 17.31 Found: C, 40.10; H, 4.43; N, 4.51; S, 9.63; F, 17, 10 The above acid was dissolved in ethyl acetate and treated with 1-adamantanamine to produce the 1-adamantanamine salt; mp 213-215 ° (solar temperature), [α] 25-47 ° (C, 1% in methanol).

Example 15 (8S) -7- (2-Mercapto-2-trifluoromethyl-1-oxopropyl) -1,4-dioxo-7-azaspiro [4.4] nonane-8-carboxylic acid, Isomer B Isomer B product from Example 13 (1.05 g, 0.0028 mol) is hydrolyzed with 2 ml of concentrated ammonia in 5 ml of water according to the procedure of Example 2 to give 0.9 g (97%) of (8S) -7- (3-mercapto- 2-trifluoromethyl-1-oxopropyl) -1,4-dioxo-7-azaspiro [4,4] nonane-8-carboxylic acid, isomer B as pale yellow viscous syrup; [α] D -1 -160 (c, 1% in ethanol). This material solidifies into a waxy solid; melting point 61 - 640 (p. 550).

Analysis Calculated for C 11 H 14 F 3 NO 5 S. 0.25 H 2 O: CI 39:58; H: 4:38; Nr4r2O; S: 9:61; F: 17:01 Found: C, 39.60; H, 4.28; N, 4.26; S, 9.62; F, 16.89 Example 16 M '1- [3- (acetylthio) -2-trifluoromethyl-1-oxopropyl] -4,4-dimethoxy-L-proline, isomers A and B Following the procedure of Example 13 but using 4,4-dimethoxy-L-proline instead of 4,4-ethylenedioxy-L-proline in part (c), 1- [3- (acetythio) -2-trifluoromethyl-1-oxopropyl] -4,4 -dimethoxy-L-proline as racemic mixture. The individual isomers can be separated in the manner set forth in Example 13. Example 17 1- (3-Mercapto-2-trifluoromethyl-1-oxopropyl) -4,4-dimethoxy-L-pgpline, isomer A and isomer B Each individual isomer product from Example 16 is hydrolyzed with concentrated ammonia according to the procedure of Example 4 to give 1- (3-mercapto-2-trifluoromethyl-1-oxopropyl) -4,4-dimethoxy-L-proline, isomer A and 1- ( 3-mercapto-2-trifluoromethyl-1-oxopropyl) -4,4-dimethoxy-L-proline, isomer B.

Example Gel 18 (85) -7- (3-mercapto-1-oxopropyl) -1,4-dioxo-7-azaspiro [4,4] nonane-8-carboxylic acid a) ((s) -7- [3- (acetylthio) -1-oxopropyl] -1,4-dioxo-7-azaspiro- [4,4] nonane-8-carboxylic acid 4,4-ethylenedioxy-L-proline is reacted with 3-acetylthiopropionyl chloride according to the procedure of Example 1 (e) to give (8S) -7- [3- (acetylthio) -1-oxopropyl] -1,4-dioxo-7-azaspiro [4.4] nonane-8-carboxylic acid b) (85) - 7- (3-Mercapto-1-oxopropyl) -1,4-dioxo-7-azaspiro [4,4] nonan-8-carboxylic acid The product from part (a) is hydrolyzed with concentrated ammonia according to the procedure of Example 2 to give ( 8S) -7- (3-mercapto-1-oxopropyl) -1,4-dioxo-7-azaspiro [4,4] nonane-8-carboxylic acid.

Example 19 1- (3-mercapto-1-oxopropyl) -4,4-dimethoxy-L-proline a) 1- [3- (acetylthio) -1-oxopropyl] -4,4-dimethoxy-L-proline 4, 4-Dimethoxy-L-proline is reacted with 3-acetylthiopropionyl chloride according to the procedure of Example 3 (d) to give 1- [3- (acetylthio) -1-oxopropyl] -4,4-dimethoxy-L-proline . b) 1- (3-Mercapto-1-oxopropyl) -4,4-dimethoxy-L-proline The product from part (a) is hydrolyzed with concentrated ammonia according to the procedure of Example 4 to give 1- (3-mercapto-1-oxo propyl) -4,4-dimethoxy-L-proline. Example 20 (85) -7- (4-Mercapto-1-oxobutyl) -1,4-dioxo-7-azaspiro [4,4] nonane-8-carboxylic acid a) (85) -7- [ 4- (Acetylthio) -1-oxobutyl] -1,4-dioxo-7-azaspiro- [4,4] nonane-8-carboxylic acid 4,4-ethylenedioxy-L-proline is reacted with 4-acetylthiobutyroyl chloride according to the procedure in Example 1 (e) to give 8 (S) -7- [4- (acetylthio) -1-oxobutyl] -1,4-dioxo-7-azaspiro [4.4] nonane-8-carboxylic acid. b) (85) -7- (4-mercapto-1-oxobutyl) -1,4-dioxo-7-azaspiro [4,4] nonane-8-carboxylic acid The product from part (a) is hydrolyzed with concentrated ammonia according to the procedure in Example 2 to give (8S) -7- (4-mercapto-1-oxobutyl) -1,4-dioxo-7-azaspiro [4.4] nonane-8-carboxylic acid.

Example 21 1- (4-Mercapto-1-oxobutyl) -4,4-dimethoxy-L-proline a) 1- [4- (acetylthio) -1-oxobutyl] -4,4-dimethoxy-L-proline 4, 4-Dimethoxy-L-proline is reacted with 4-acetylthiobutyroyl chloride according to the procedure of Example 3 (d) to give 1- [4- (acetylthio) -1-oxobutyl] -4,4-dimethoxy-L-proline . b) 1- (4-mercapto-1-oxobutyl)> 4,4-dimethoxy-L-proline The product from part (a) is hydrolyzed with concentrated ammonia according to the procedure of Example 4 to give 1- (4-mercapto-1-oxo - butyl) -4,4-dimethoxy-L-proline. $> CH __; 33 Exemgel 22 (8S) -7- (2-mercapto-1-oxoethyl) -1,4-dioxo-7-azaspiroI4,4] nonane-8-carboxylic acid a) (8S) -7- [2 - (acetylthio) -1-oxoethyl] -1,4-dioxo-7-azaspiro [4,4] nonane-8-carboxylic acid 4,4-ethylenedioxy-L-proline is reacted with acetylthioacetyl chloride according to the procedure of Example 1 (e) to give (8S) -7- [2- (acetylthio) -1-oxoethyl] -1,4-dioxo-7-azaspiro [4.4] nonane-8-carboxylic acid. b) (8S) -7- (2-mercapto-1-oxoethyl) -1,4-dioxo-7-azaspiro [4,4] nonan-8-carboxylic acid The product from part (a) is hydrolyzed with concentrated ammonia according to the procedure in Example 2 to give (85) -7- (2-mercapto-1-QW oxoethyl) -1,4-dioxo-7-azapiro [4,4] nonane-8-carboxylic acid.

Example Gel 23 1- (2-Mercapto-1-oxoethyl) -4,4-dimethoxy-L-proline a) 1- [2- (acetylthio) -1-oxoethyl] -4,4-dimethoxy-L-proline 4, 4-Dimethoxy-L-proline is reacted with acetylthioacetyl chloride according to the procedure of Example 3 (d) to give 1F [2- (acetylthio) -1-oxoethyl] -4,4-dimethoxy-L-proline. b) 1- (2-Mercapto-1-oxoethyl) -4,4-dimethoxy-L-proline The product from part (a) is hydrolyzed with concentrated ammonia according to the procedure of Example 4 to give 1- (2-mercapto-1-oxo ethyl) -4,4-dimethoxy-L-proline. 451 859 34 Example 24 [7 (S), 8S) -7- (3-mercapto-2-ethyl-1-oxopropyl] -4,4-dioxo-7-azaspiro [4,4] nonane-8-carbq§ Acidic acid a) [7 (S), 8S) -7- [3- (acetylthio) -2-ethyl-1-oxopropyl] -1,4-dioxo-7-azaspirol4,4] nonane-8-carboxylic acid 4 , 4-ethylenedioxy-L-proline is reacted with D-3-acetylthio-2-ethylpropionyl chloride according to the procedure of Example 1 (e) to give [7 (S), 8S] -7- [3- (acetylthio) -2- ethyl 1-oxopropyl] -1,4-dioxo-7-azaspiro [4,4] nonane-8-carboxylic acid. b) [7 (S), 8S] -7- (3-mercapto-2-ethyl-1-oxopropyl) -1,4-dioxo-7-azaspiro [4,4] nonane-8-carboxylic acid (a) hydrolyzed with concentrated ammonia according to the procedure of Example 2 to give [7 (S), 8S] -7- (3-mercapto-2-ethyl-1-oxopropyl) -1,4-dioxo-7-azaspiro [4 , 4] nonane-8-carboxylic acid.

Example 25 (S) -1- (3-Mercapto-2-ethyl-1-oxopropyl) -4,4-dimethoxy-L-proline a) (S) -1- [3- (acetylthio) -2-ethyl- 1-oxopropyl] -4,4-dimethoxy-L-Broline 4,4-dimethoxy-L-proline is reacted with D-3-acetylthio-2-ethyl-propionyl chloride according to the procedure of Example 3 (d) to give (S) -1- [3- (acetylthio) -2-1-oxopropyl] -4,4-dimethoxy-L-proline. b) (S) -1- (3-mercapto * 2-ethyl-1-oxopropyl) -4,4-dimethoxy-L-proline The product from part (a) is hydrolyzed with concentrated ammonia according to the procedure of Example 4 and gives (S) -1- (3-mercapto-2-ethyl-1-oxopropyl) -4,4-dimethoxy-L-proline.

Example Gel 26 [8S] -7- (3-mercapto-2-trifluoromethyl-1-oxopropyl) -7-aza-1,4-dithiazpiro [4,4] nonane-8-carboxylic acid a) 3 ~ [[(4- methoxy) phenylmethyl] thio] -2-trifluoromethylpropionyl chloride A pure mixture of 1-trifluoromethylacrylic acid (3.9 g) and 4-methoxybenzylthiol (4.3 g) is stirred at 100-110 ° for 1 hour.

The mixture is allowed to cool to room temperature and the solid is recrystallized from cyclohexane to give 3 - [[(4-methoxy) phenylmethyl] thio] -2-trifluoromethylpropionic acid; melting point 72 - 74 °.

Treatment of this acid with thionyl chloride gives 3 - [[(4-methoxy) -phenylmethyl] thio] -2-trifluoromethylpropionyl chloride. b) [8S1-7- [3 - [[(4-methoxy) phenylmethyl] thio] -2-trifluoromethyl-1-oxopropyl] -7-aza-1,4-dithiazpiro [4,4] nonane-8-carboxylic acid 3 - [[(4-methoxy) phenylmethyl] thio] -2-trifluoromethylpropionyl chloride from part (a) is reacted with 4,4-ethylenedithio-L-proline according to the procedure of Example 9 (d) to give [8S ] -7- [3F [[(4-methoxy) phenylmethyl] thio] -2-trifluoromethyl-1-oxopropyl] -7-aza-1,4-dithiazpiro [4,4] nonane-8-carboxylic acid. 451 859 c) [8S] -7 - (- mercapto-2-trifluoromethyl-1-oxopropyl) -7-aza-1,4-dithiazpiro [4,4] nonane-8-carboxylic acid The product from part (b) is mixed with trifluoroacetic acid and anisole under nitrogen. The solvents are removed in vacuo to give the remaining [8S] -7- (3-mercapto-2-trifluoromethyl-1-oxopropyl) -7-aza-1,4-dithiazpiro [4,4] nonane-8-carboxylic acid.

Example 27 1- (3-Mercapto-1-oxopropyl) -4,4-dimethylthio-L-proline a) 4-Keto-L-proline, hydrobromide To 4.0 g (0,05 mol) of N-carbobenzyloxy-4 -keto-L-proline was added 20 ml of hydrogen bromide in acetic acid (30 - 32%). The mixture is stirred occasionally for a period of 8 minutes. At the end of this period (foaming ceases) the yellow-orange solution is layered with 250 with ether which decomposes the gum-like product.

The ether is discarded and the resulting sticky solid is decomposed with new ether and finally with 50 ml of acetonitrile to give 4-keto-L-proline, hydrobromide as a crystalline solid weighing 2.7 g (85%), (decomposition) , gull -49 ° (c, 1% in water). b) 1- [3- (acetylthio) -1-oxopropyl] -4-oxo-L-proline A stirred solution of 4.1 g (0.0195 mol) of 4-keto-L-proline, hydrobromide in 50 ml of water cooled to 50 and treated portionwise with solid sodium carbonate (foaming is controlled by the addition of a few drops of ether) to pH 8.0 (approximately 2 g is required). With continued stirring and cooling, a solution of 3.5 g (0.012 mol) of 3-acetylthiopropanoyl chloride in 5 ml of ethyl acetate is added portionwise using a pipette while maintaining the pH at 7.0-8.0 by dropwise addition of 25% (w / v) sodium carbonate solution (approximately 10 ml).

After about 10 minutes, the pH stabilizes at 8.0 - 8.4. After further stirring and cooling for a total of 1 hour, the solution is washed with ethyl acetate (2 x 50 ml), layered with 50 ml of ethyl acetate, stirred, cooled, thoroughly acidified with concentrated hydrochloric acid to pH 2. 0, saturated with sodium chloride and the layers separated. The aqueous phase is extracted with additional ethyl acetate (3 x 50 ml), the combined organic layers are dried (MgSO 4) and the solvent is evaporated, finally at 0.2 mm to give 4.8 g of a yellow-orange glass-like residue. This residue is dissolved in 35 ml of ethyl acetate and treated with a solution of 3.5 g of dicyclohexylamine in 5 ml of ethyl acetate. Upon grafting and shredding, crystalline 1- [3- (acetylthio-1-oxopropyl)] f4-oxo-L-prolindicyclohexylamine salt is separated off, which after cooling overnight weighs 2.7 g (almost colorless), m.p. , [a1ê6 -z4 ° (c, 1% i cHc1¿).

This dicyclohexylamine salt is converted to the free acid using potassium bisulfate as described in Example 1 (e) to give 3.7 g of 1- [3- (acetylthio) -1-oxopropyl] -4-oxo-L-proline as a bright yellow glass-like solid. (N c) 1- [3- (acetylthio) -1-oxopropyl] -4,4-dimethylthio-L-proline 1- [3- (acetylthio) -1-oxopropyl] -4-oxo-L-proline is reacted with methylthiol according to the procedure of Example 9 (a) to give 1- [3- (acetylthio) -1-oxopropyl] -4,4-dimethylthio-L-proline. d) 1- (3-Mercapto-1-oxopropyl) -4,4-dimethylthio-L-proline The product from part (a) is hydrolyzed with concentrated ammonia according to the procedure of Example 2 to give 1- (3-mercapto-1-oxo propyl) -4,4-dimethylthio-L-proline. 451 839 38 Example 28 (S, S, S, S) -7,7 '- [dithiobis (2-methyl-1-oxo-3,1-propanediyl)] bis- [1,4-dioxa-7-azaspiro [4,4] nonane-8-carboxylic acid] [7 (S), 8S] -7- (3-mercapto-2-methyl-1-oxopropyl) -1,4-dioxo-7-aza-spiro [4, 4] Nonane-8-carboxylic acid (3.0 g, 0.0109 mol) from Example 2 is dissolved in 80 ml of water and the pH is adjusted to 6.5 with 1N sodium hydroxide. To this stirred solution is added dropwise a total of 11 ml of 0.5 M iodine solution in 95% ethanol (6.34 g iodine / 50 ml solution) while maintaining the pH of the mixture at 5.5 - 6.5 with 1N sodium hydroxide. After 15 minutes, remove traces of excess iodine with dilute sodium thiosulfate and concentrate the solution to about 50 ml, cool and acidify with 1: 1 hydrochloric acid. 30 ml of methylene chloride are added and the mixture is measured with sodium chloride, stirred and the layers are separated. The aqueous phase is extracted with additional methylene chloride (3 x 20 ml), the combined organic layers are dried (MgSO 4) and the solvent is evaporated, finally at 0.2 mm. The brittle residue is triturated under ether and the evaporation is repeated to give 8.2 g of pale yellow solid residue. This material is redissolved in 50 ml of methylene chloride, washed with water (3 x 10 ml), the combined aqueous layers are re-extracted with 20 ml of methylene chloride and the combined layers are dried (MgSO 4). Evaporation and decomposition with ether in the manner described above give 2.2 g (73%) of cream amorphous solid (S, S, S, S) -7,7 '- [dithiobis (2-methyl-1-oxo- 3,1-propanediyl) bis [1,4-dioxo-7-azaspiro [4,4] nonane-8-carboxylic acid]; melting point 61 - 630 (foaming). S. 500), [u] š6 ~ 92 °, (c, 1% in ethanol).

Analysis Calculated for C 22 H 32 N 2 O 10 S. H 2 O: C, 46.63; H, 6.05; N, 4.94; S, ll, 31l Found: C, 46.52; H, 6.29; N, 4.63; S, 10.96 451 839 Exemgel 29 (S, S, S, S) -7,7 '- [dithiobis (2-methyl-oxo-3,1-propanediyl)] bis- [7-aza-1,4 -ditiaspiro [4,4] nonane-8-carboxylic acid] [7 (S), 8S] -7- (3-mercapto-2-methyl-1-oxopropyl) -7-aza-1,4-dithiaspiro [ 4.4] Nonane-8-carboxylic acid from Example 10 is reacted with iodine according to the procedure of Example 125 to give (S, S, S, S) - 7,7 '- [dithiobis (2-methyl-1-oxo-3 , 1-propanediyl)] bis- [7-aza-1,4-dithiazpiro [4,4] nonane-8-carboxylic acid].

Example gel 30 (S, S, S, S) -1,1 '- [dithiobis (2-methyl-1-oxo-3,1-propanediyl)] bis- [4,4-dimethoxy-L-proline] (S ) -1- (3-mercapto-2-methyl-1-oxopropyl) -4,4-dimethoxy-L-proline from Example 4 is reacted with iodine according to the procedure of Example 125 and gives (S, S, S, S) -1,1 '- [dithiobis (2-methyl-1-oxo-3,1-propanediyl)] bis [4,4] -dimethoxy-L-proline].

Example Gel 31 [7 (S), 8 (S) 1-7- [3- (acetylthio) -2-methyl-1-oxopropyl] -1,4-dioxo-7-azaspiro [4.4] nonane-8- carboxylic acid A solution of the product in Example 1l ether is treated with a slight excess of diazomethane. After standing at room temperature for 2 hours, the solvent is evaporated to give [7 (S), 8S] -7- [3-acetylthio) -2-methyl-1-oxopropyl] -1,4-dioxo-7- azaspiro [4.4] nonane-8-carboxylic acid, methyl ester. Example 32 f [7 (S), 8S] -7- (3-mercapto-2-methyl-1-oxopropyl) -1,4-dioxo-7-azaspiro [4.4] nonane-8-carboxylic acid methyl ester The product of Example 31 is hydrolyzed with concentrated ammonia according to the procedure of Example 2 to give [7 (S), 8S] -7- (3-mercapto-2-methyl-1-oxopropyl) -1,4-dioxo-7- azaspiro [4,4] nonan-8-carboxylic acid, methyl ester.

Example 33 (S) -1- [3- (Acetylthio) -2-methyl-1-oxopropyl] -4,4-dimethoxy-L-Broline, methyl ester A solution of the product of Example 3 in ether is treated with a slight excess of diazomethane . After standing at room temperature, the solvent is evaporated to give (S) -1- [3- (acetylthio) -2-methyl-1-oxopropyl] -4,4-dimethoxy-L-proline, methyl ester.

Example 34 (S) -1- (3-Mercapto-2-methyl-1-oxopropyl) -4,4-dimethoxy-L-proline, methyl ester The product of Example 33 is hydrolyzed with concentrated ammonia according to the procedure of Example 4 to give (S ) 1- (3-mercapto-2-methyl-1-oxopropyl) -4,4-dimethoxy-L-proline, methyl ester. Example 35 [7 (S), 8S] -7- (3-mercapto-2-methyl-1-oxopropyl) -1,4-dioxo-7-azaspiro [4.4] nonane-8-carboxylic acid, sodium salt A solution of 1.0 g of the product of Example 2 is dissolved in ml of water and treated with one equivalent of sodium bicarbonate. The solution is lyophilized to give [7 (S), 8S] -7- (3-mercapto-2-methyl-1-oxopropyl) -1,4-dioxo-7-azaspiro [4,4] nonane-8-carboxylic acid , sodium salt In the same way, the corresponding potassium salt is obtained using potassium bicarbonate.

Example 36 (S) -1- (3-Mercapto-2-methyl-1-oxopropyl) -4,4-dimethoxy-L-proline, sodium salt pa A solution of 1.0 g of the product of Example 4 is dissolved in ml of water. and treated with one equivalent of sodium bicarbonate. The solution is lyophilized to give (S) -1- (3-mercapto-2-methyl-1-oxopropyl) -4,4-dimethoxy-L-proline, sodium salt.

In the same way but by using potassium bicarbonate the corresponding potassium salt is obtained.

Example 37 1000 tablets each containing the following ingredients: [7 (S), 8S] -7- (3-mercapto-2-methyl-1-oxopropyl) -1,4-dioxo-7-azaspiro [4.4] nonane 8-Carboxylic acid 100 mg Maize starch 50 mg Gelatin 7.5 mg 451 859. J-5, 42 Avicel (microcrystalline cellulose) 25 mg Magnesium stearate 2.5 mg 185 mg is prepared (from sufficient bulk amounts) by mixing [7 (S ), 8S] -7- (3-mercapto-2-methyl-1-oxopropyl) -1,4-dioxo-7-azaspiro [4,4] nonane-8-carboxylic acid and corn starch with an aqueous solution of the gelatin. The mixture is dried and ground to a fine powder. Avicel and then magnesium stearate are mixed while granulating. This mixture is then compressed in a tablet press into 100 tablets each containing 100 mg of the active ingredient.

Example Gel 38 Tablets each containing 100 mg of (S) -1- (ε-mercapto-2-methyl-1-oxopropyl) -4,4-dimethoxy-L-proline are prepared as described in Example 134.

Exemgel 39 1000 tablets each containing 50 mg [7 (S), 8S] -7- (3-mercapto-2-methyl-1-oxopropyl) -1,4-dioxo-7-azaspiroI4,4] -nonane-8- Carboxylic acid is prepared from the following ingredients: [7 (S), 8S] -7- (3-mercapto-2-methyl-1-oxopropyl) -1,4-dioxo-7-aza-spiro [4,4] nonane-8 -carboxylic acid 50 g lactose 100 g Avicel 150 g corn starch 50 g magnesium stearate 5 g [7 (S), BS1-7- [3-mercapto-2-methyl-1-oxopropyl) -1,4-dioxo-7-azaspiro [ 4.4] nonane-8-carboxylic acid, lactose and Avicel are mixed and then mixed with the corn starch. Magnesium stearate 451,839 is added. The dry mixture is compressed in a tablet press into 1000 tablets of 355 mg each containing 50 mg of active ingredient. The tablets are coated with a solution of Methocel E (methylcellulose) comprising as color a pigment containing yellow No. 6.

Example 40 Tablets each containing 50 mg of (S) -1- (3-mercapto-2-methyl-1-oxopropyl) -4,4-dimethoxy-L-proline are prepared as described in Example 136.

Example Gel 41 Two pieces of No. 1 gelatin capsules each containing 100 mg [7 (S), 8S] -7- (3-mercapto-2-methyl-1-oxopropyl) -1,4-dioxo-7-azaspiro [4.4] nonane-8-carboxylic acid, sodium salt is filled with a mixture of the following ingredients: [7 (S), BS] -7- (3-mercapto-2-methyl-1-oxopropyl) -1,4-dioxo-7-aza- spiro [4,41-nonan-8-carboxylic acid, sodium salt 100 mg magnesium stearate 7 mg lactose 193 mg Exemgel 42 Gelatin capsules containing 100 mg (S) -1- (3-mercapto-2-methyl-1-oxopropyl) -4,4-dimethoxy -L-proline, sodium salt is prepared as described in Example 138.

Example 43 An injectable solution is prepared as follows: "" in 44 [7 (S), 8S] -7- (3-mercapto-2-methyl-1-oxopropyl) -1,4-dioxo-7-aza- spiro [4,4] nonane-8-carboxylic acid 500 g Ä methylparaben 5 g Q propylparaben lg sodium chloride 25 g water for injection qs 5 l The active substance, preservative and sodium chloride are dissolved in 3 liters of water and then the volume is transferred to liters. filtered through a sterile filter and aseptically filled into pre-sterilized vials which are then sealed with pre-sterilized rubber seals, each vial containing 5 ml of solution at a concentration of 100 mg of active ingredient per ml of solution for injection.

Example Gel 44 An injectable solution containing (S) -1- (3-mercapto-2-methyl-1-oxopropyl) -4,4-dimethoxy-L-proline is prepared as described in Example 43.

Example gel 4§¿ 6000 tablets each containing the following ingredients: [7 (S), 8S] -7- (3-mercapto-2-methyl-1-oxopropyl) -1,4-dioxo-7-azaspiro [4,4] nonan-8-carboxylic acid 100 mg Avicel (microcrystalline cellulose) 100 mg hydrochlorothiazide 12.5 mg lactose USP 113 mg of corn starch 17.5 mg of stearic acid USP 7 'mg 350 mg are prepared from sufficient bulk amounts by processing [7 (S), 8S] -7- (3-mercapto-2-methyl-1-oxopropyl) -1,4 dioxo-7,451,839 azaspiro [4,4] nonane-8-carboxylic acid, Avicel and a proportion of the stearic acid. The processed product is ground and passed through a No. 2 sieve, then mixed with hydrochlorothiazide, lactose, corn starch and the remainder of the stearic acid. The mixture is compressed into 350 mg capsule-shaped tablets in a tablet press. The tablets are cut for division into halves.

Example 46 Tablets each containing (S) -1- (3-mercapto-2-methyl-1-oxopropyl) -4,4-dimethoxy-L-proline and hydrochlorothiazide can be prepared as described in Example 45.

The product of Examples 1, 3 and 6 to 36 can also be prepared according to the procedures of Examples 37-46. in!!!

Claims (2)

451 839 1 1% PATENT REQUIREMENTS A process for the preparation of a compound of the formula: R 5 represents x hydrogen or lower alkyl; R 3 represents hydrogen, lower alkyl or halogen-substituted lower alkyl; X and X 1 2 represent oxygen or sulfur; R 1 and R 2 represent lower alkyl or R 1 and R 2 are joined in a polymethylene chain to form a 5- or 6-membered ring; m is 0, 1 or 2; and R 5 is hydrogen, lower alkanoyl, benzoyl or a sulphide of the formula: 'poison -S - (CH 2) E-' CH-CO- ~ N OOR and thereby forms a bis-symmetrical disulphide product characterized by Coupling a substituted proline of the formula: HN CH - COOR with an acid or its chemical equivalent such as an acid chloride of the formula: n R5 '- S - (CH2) m-- CH-- COOH wherein Rs' is lower alkanoyl or benzoyl, 451 839 471 and removes said group to form a product wherein R is hydrogen and oxidizes said product with iodine to form the bis-symmetrical disulfide product. 2. A process according to claim 1, characterized in that R 5 'is lower alkanoyl or benzoyl and that said group is removed by hydrolysis or ammonolysis to give the product, wherein R 5 is hydrogen.