NO142241B - PROCEDURE FOR PREPARING A STABLE, Aqueous SOLUTION FOR TOPICAL USE OF LIVING TISSUE - Google Patents

Description

Process for the production of 17a-hydroxy-20-oxo-4-pregnene-(3,2-c)-pyrazole compounds.

The present invention relates to a process for the production of hitherto unknown 17a-hydroxy-20-oxo-4-pregnene-(3,2-c)-pyrazole compounds of one of the general formulas:

where denotes g-hydroxy or keto, R 2 denotes hydrogen, fluorine or methyl, R3 denotes α-methyl, Ø-methyl or methylene, R4 denotes hydrogen or acyl, Rg denotes hydrogen, acyl, alkyl, cycloalkyl, arylalkyl or an aryl group which can optionally be substituted with a halogen atom, an alkyl group or an alkoxy group, and X denotes hydrogen or halogen.

The new (3,2-c)-pyrazole steroids have a strong anti-inflammatory effect, significantly stronger than the parent steroids, and they are particularly effective for the treatment of arthritis and related diseases, as they produce a cortisone-like effect in small doses, whereby unwanted side effects are kept in check.

The process according to the invention for the production of the new (3,2-c)-pyrazole steroids is distinguished by the fact that a compound of the general formula:

where R-^, Rj, R3 and X have the meanings given above, is reacted with an alkyl formate and sodium hydride in an inert atmosphere, whereby a compound of the general formula is obtained: where R-p R 2 > Rq °S X when the meanings given above, which compound is reacted in an inert atmosphere with a hydrazine of the general formula R5NHNH2, where R,- has the above meaning, or a salt thereof, whereby a compound of one of the general formulas is obtained:

where R-p R2) R3, R5 and X have the meanings given above, which compound, if Rg is hydrogen, is, if desired, reacted with an acylating agent, an alkyl halide or an arylalkyl halide, whereby the hydrogen is replaced by an acyl-,' alkyl- or arylalkyl- group, whereupon a possible 11-keto group is, if desired, reduced to the corresponding 11(3-hydroxy group, after which the compound is reacted with an acid to remove the methylenedioxyd groups, and the

with the resulting 21-hydroxy compound, if desired, is converted to a 2.1-ester by reaction with an acylating agent.

The reaction of the starting material 17a,20,20,21-bis-(methylenedioxy)-4-pregnen-3-one of formula II with alkyl formate and sodium hydride in an inert atmosphere is suitably carried out by dissolving the steroid in a solvent such as benzene and cools the resulting solution to room temperature, after which ethyl formate is added. The air in the reaction vessel is replaced with nitrogen, sodium hydride is added, and the mixture is stirred at room temperature for several hours.

For reaction of 17a , 20 , 20 , 21-bis(methylenedioxy)-2-hydroxymethylene-H-pregnen-3-one of formula III with the hydrazine compound, it is convenient to dissolve the steroid in absolute ethanol and to heat the solution with the hydrazine compound (or a salt of this compound in the presence of a buffer, such as sodium acetate) in an inert atmosphere. If the hydrazine compound is hydrazine hydrate, the steroid solution can advantageously be added to a 1:1 solution of hydrazine hydrate and absolute ethanol, after which the mixture is boiled under a nitrogen atmosphere for approx. 4 5 minutes with reflux cooling. In this case, a compound of formula IV is obtained where Rg is hydrogen. This hydrogen can, if desired, be replaced by reacting the compound with an alkylating agent, aralkylating agent or acylating agent. Benzoic anhydride, tertiary butyl acetyl chloride, acetic anhydride, propionic anhydride or a polybasic anhydride, such as 6,B-dimethylglutaric anhydride or succinic anhydride can be suitably used as an acylating agent. The acylation is conveniently carried out in the presence of an organic base, such as pyridine.

Reduction of an 11-keto radical in an obtained compound of one of the formulas IV to the corresponding 11-3-hydroxy group can be carried out e.g. by adding a saturated solution of sodium borohydride to a solution of the steroid in a mixture of triethylamine and isopropanol, to which mixture it is preferred to add a small amount of water, and then allowing the mixture to stand overnight.

The reaction of the obtained compound of one of the formulas IV (after any substitutions in the 1'- or 2'- and/or 11-position) with acid to remove the methylenedioxide groups can be carried out, e.g. with a 60% aqueous solution of formic acid.

The reaction usually results in a mixture of a 21-hydroxy and a 21-acyloxy compound, where the 21-acyl group originates from the organic acid used in the reaction. A mixture of the steroids containing a 21-hydroxy and a 21-acyloxy group can be separated by chromatography. Any acyl groups found at R^ or at F can, if desired, be removed by treating the steroid with sodium methoxide in methanol at room temperature.

The method according to the invention is illustrated in the following examples.

Example 1

1.350 g of 17a,20,20,21-bis(methylenedioxy)-1<g->hydroxy-16a-methyl-4-pregnen-3-one is dissolved in 23 ml of dry, hot benzene, and the resulting solution is cooled to room temperature and treated with 0.96 ml of freshly distilled ethyl formate. The air in the reaction vessel is displaced with nitrogen, and 560 mg of sodium hydride (as a 58% dispersion in mineral oil) is added. The container is evacuated again and filled with nitrogen, and the mixture is stirred with a magnetic stirrer

room temperature for 18 hours. The mixture is poured into an excess of a saturated aqueous solution of sodium dihydrogen phosphate, and the product is extracted 4 times with benzene. The organic extracts are washed 3 times with water and dried over sodium sulfate. By distilling off the solvent, an impure product is obtained, which is dissolved in ether and purified as the sodium salt by extraction with a 10% solution of sodium carbonate. The aqueous alkaline extracts are made acidic again with an excess of a saturated aqueous solution of sodium dihydrogen phosphate and extracted with ether and with chloroform. The combined organic extracts are dried over sodium sulfate and evaporated to dryness, thereby obtaining 850 mg of 17a,20,20,21-bis(methylenedioxy)-116-hydrozy-2-hydroxymethylene-16a-methyl-4-pregnen-3 -on, which has the following properties: X ^^sian°"''= 249.8 my (e = 249), X max = 307.5 mp (e = 100).

The formed 17a,20,20,21-bis(methylenedioxy)-llg-hydroxy-2-hydroxymethylene-16a-methyl-4-pregnen-3-one is dissolved in 9.2 ml of absolute ethanol and treated with a solution of 0, 16 ml hydrazine hydrate dissolved in 0.16 ml absolute ethanol. The mixture is boiled with reflux cooling in a nitrogen atmosphere for approx. 4 5 minutes and then evaporated to dryness under reduced pressure. The evaporation residue is washed 3 times with cold water, and the formed amorphous substance is dried at 80° C for 1 hour in a strong vacuum, whereby approx. 820 mg of 17a,20,20,21-bis(methylenedioxy)-16a-methyl- (3,2-c)-pyrazole-

4-pregnen-ll<g->ol, X max = 261 my (e = 220).

Add 0.5 ml of acetic anhydride. The mixture is allowed to stand at room temperature. A mixture of ice and water is then added. After a delay of approx. After 30 minutes, the product is extracted with ethyl acetate. The ethyl acetate extract is washed sequentially with water, ice-cold IN sulfuric acid (until the pH of the aqueous layer is 1 - 3), saturated aqueous sodium bicarbonate (until the pH of the aqueous layer is 8), and water (until the aqueous layer reacts neutrally). The ethyl acetate solution is dried over anhydrous sodium sulfate. The solvent is then distilled off at approx. 40° C in vacuum, whereby 1'-acetyl-17a,20,20,21-bis-(methylenedioxy)-16a-methyl-(3,2-c)-pyrazole-4-pregnen-11B- etc., which are isolated by adding water and filtering.

1'-acetyl-17a,20,20,21-bis(methylenedioxy)-16a-methyl-(3,2-c)-pyrazol-4-pregnen-113-ol (720 mg) is heated on a steam bath with 24 ml of a 60% aqueous solution of formic acid in approx. 30 minutes. Excess reagent is removed in vacuum using a water bath of 50° C as a heat source. The evaporation residue is rinsed 4 times with n-hexane and then dried at 60° C in a strong vacuum, whereby an amorphous substance is obtained, which is a mixture of 1'-acetyl-113,17a,21-trihydroxy-16a-methyl-( 3,2-c)-pyrazol-4-pregnen-2o-one and 1'-acetyl-21-formyloxy-118,17a-dihydroxy-16a-methyl-(3,2-c)-pyrazol-4-pregnen- 20-on, which compounds are separated by chromatography.

500 mg of this impure product is dissolved in 2.4 ml of pure methanol and allowed to stand and react with 0.9 ml of a 1.3 3 N solution of sodium methoxide in methanol at room temperature under a nitrogen atmosphere for 10 minutes. The alkoxide is neutralized with acetic acid,

and the mixture is then evaporated to dryness and rinsed with n-hexane. The evaporation residue is washed with water, filtered and dried to constant weight, whereby approx. 375 mg of 118,17a,21-trihydroxy-16a-methyl-(3,2-c)-pyrazol-4-pregnen-2o-one, X ^g^<01> = 263 my (£ = 233).

Example 2

2.60 g of 17a,20,20,21-bis(methylenedioxy)-9a-fluoro-16a-methyl-4-pregnene-3,11-dione are dissolved in 95 ml of dry benzene using dry apparatus and treated with 2, 43 ml of freshly distilled ethyl formate. About. 1.19 g of a dispersion of sodium hydride i

mineral oil (approx. 51%) is added, followed by approx. 1.19 g freshly prepared dry sodium methoxide (dried at approx. 17 5° C with oil pump 1 4 hours). The air in the apparatus is again displaced with nitrogen, and the mixture, which immediately turns yellow, is stirred at room temperature for 1 -

1.5 hours. At this point, the color of the reaction mixture is dark orange. The mixture is cooled in an ice bath, and a cold, saturated solution of sodium dihydrogen phosphate is gradually added to cleave excess hydride and to neutralize the alkoxide. Ether is added and the layers are separated. The aqueous layers are extracted back with ether, and the combined organic layers are washed acid-free with water and then extracted 3-4 times with a 5% aqueous solution of sodium bicarbonate. These extracts are allowed to stand. The product is then extracted 4-5 times with a cold 2% aqueous solution of sodium hydroxide. To avoid emulsification, the aqueous alkali is carefully poured into the separatory funnel, and the layers are separated without shaking the funnel. The last two extracts can be shaken with care. The dark liquid is extracted back twice with ether, and finally acidified cold with a saturated aqueous solution of sodium dihydrogen phosphate. The neutral ether-benzene fraction is set aside and treated as described below. The product is extracted with ether, and the ether extracts are washed acid-free with a saturated solution of sodium chloride. After drying over magnesium sulfate, the ether solution is evaporated to dryness, and the amorphous product is recrystallized from methanol, whereby 1.07 g (39%) of product with a melting point of 230 - 23 2° C is obtained, when the melting point sample is heated from 19 5° C The substance is suitable as a starting material for the subsequent steps. The ultraviolet absorption in methanol containing 2% 2.5 N NaOH shows X ma^s <= >2 39 my (e = 342) and X max = 360 my (e = 213). The mother liquors give a product of lower purity. An analytical sample of 17a , 20 , 20 , 21-bis-(methylenedioxy)-9a-fluoro-2-hydroxymethylene-16a-methyl-4-pregnene-3,11-dione, formed by recrystallization from ether and from methanol, gives a lower melting point (221 - 224° C), but improves the ultraviolet absorption (X <e>!r<n> = 239 my (e = 429), 359 , 5 my (e = 263)).

JIlclXS

1.00 g of 17a,20,20,21-bis(methylenedioxy)-9a-fluoro-2-hydroxymethylene-16a-methyl-4-pregnen-3,11-dione (melting point 230 - 232° C) is suspended in 44 ml absolute ethanol and treated with 0.38 ml of hydrazine hydrate (99 - 100%). The air in the apparatus is displaced with nitrogen, and the mixture is rapidly heated to the boiling point. After boiling for 1 hour with reflux cooling, the mixture is further evaporated

dryness. The oily evaporation residue is treated with water, and the amorphous material is removed by filtration, washed thoroughly with water and dried. The yield is approx. 900 ml. The crude product is dissolved in absolute ethanol and concentrated in vacuo, until a solid is separated. This substance is redissolved by heating and set aside for slow crystallization, whereby 700 mg of 17a,20,20,21-bis(methylenedioxy)-9a-fluoro-16a-methyl-(3,2-c)-pyra is obtained -

PH DH

zol-4-pregnen-ll-one, X = 260 my (e = 215). The substance melts above 300°C.

455 mg of 17a,20,20,21-bis(methylenedioxy)-9a-fluoro-16a-methyl-(3,2-c)-pyrazol-4-pregnen-11-one are suspended in 75 ml of a solution of sodium borohydride in isopropanol, which is produced by slurrying an excess of sodium borohydride in isopropanol, vigorous stirring for approx. 15 minutes and filtration to separate excess sodium borohydride. 0.816 ml of a solution of 0.55 ml of triethylamine in 1.45 ml of isopropanol is added to the suspension. The mixture is stirred, and as much methylene chloride is added (approx.

30 ml) while cooling so that the mixture becomes homogeneous. A drop of water (approx. 1/20 ml) is added, and the mixture is stirred in a nitrogen atmosphere at room temperature for 18 hours. Some insoluble substance is usually excreted during the reaction. The mixture is then cooled, and excess sodium borohydride is decomposed by adding cold 2.5 N hydrochloric acid. The mixture (pH approx. 5) is evaporated to dryness in a vacuum and the evaporation residue is washed with water and dried, thereby obtaining 42 5 mg of 17a,20,20,21-bis(methylenedioxy)-9a-fluoro-IIg-hydroxy-16a-methyl -(3,2-c)-pyrazole-4-pregnene, which shows no saturated carbonylab sorption in the infrared region (Nujol). Melting point 240° C during decomposition. The hydrogen chloride is further characterized by a hydrogen bond (3.5 - 4.5 y) and by sharp maxima at 6.1 y and 6.2 7 y. The hydrogen chloride is insoluble in water and in methylene chloride. (In the presence of both solvents, the salt hydrolyzes to give the free amine, which is insoluble in methylene chloride). The ultraviolet absorption of the hydrogen chloride shows X CH 3 OH= 265 my

m^t-K p

(e = 208). The product chars at approx. 273° C. Analysis for chlorine: Calculated 7.14%; found: 7.14%.

To a solution of 100 mg of 17a,20,20,21-bis(methylene-dioxy)-9a-fluoro-118-hydroxy-16a-methyl-(3,2-c)-pyrazole-4-pregnene in 2 ml of pyridine add 0.5 ml of acetic anhydride. The mixture is allowed to stand for 18 hours at room temperature. A mixture of ice and water is then added. After a delay of approx. After 30 minutes, the product is extracted with ethyl acetate. The ethyl acetate extract is washed sequentially with water, ice-cold 1 N sulfuric acid (until the pH of the aqueous layer is 1 - 3), saturated aqueous sodium bicarbonate (until the pH of the aqueous layer is 8), and water (until the aqueous layer reacts neutrally). The ethyl acetate is then distilled off at approx.

40° C in vacuum, whereby 1'-acetyl-17a,20,20,21-bis(methylenedioxy)-9a-fluoro-118-hydroxy-16a-methyl-(3,2-c)-pyrazole is obtained -4-pregnene, which is isolated by adding water and filtering.

1'-Acetyl-17a,20,20,21-bis-(methylenedioxy)-9a-fluoro-116-hydroxy-16a-methyl-(3,2-c)-pyrazole-4-pregnene (25 mg) is heated on a steam bath with 6 ml of a 50% aqueous solution of formic acid for approx. 30 minutes. Excess reagent is removed under reduced pressure in a water bath at approx. 50° C. The evaporation residue is rinsed with n-hexane. The evaporation residue is then dissolved in acetone and precipitated with n-hexane, whereby an amorphous mixture of 9a-fluoro-113,17a,21-trihydroxy-16a-methyl-(3,2-c)-pyrazole-4-pregnene-20 is obtained -one and 11 -acetyl-9a-fluoro-21-formyloxy-116,17a-dihydroxy-16a-methyl-(3,2-c)-pyrazol-4-pregnen-20-one, which compounds are separated by chromatography .

500 mg of this crude product is dissolved in 2.4 ml of pure methanol and reacted with 0.9 ml of a 1.33 N solution of sodium methoxide in methanol at room temperature under a nitrogen atmosphere for 10 minutes. The alkoxide is neutralized with acetic acid, and the mixture is then evaporated to dryness, filtered and dried to constant weight to 9α-fluoro-118,17α,21-trihydroxy-16α-methyl-(3,2-c)-pyrazole-4-pregnene-20 -on. The hydrochloride melts at 300° C during decomposition.

Example 3

About. 6 g of 17a,20,20,21-bis(methylenedioxy)-116-hydroxy-16a-methyl-4-pregnen-3-one is suspended for approx. 35 ml of dry benzene, and to this suspension add 6 ml of ethyl formate and approx. lg freshly prepared sodium methoxide. The mixture is allowed to stand at room temperature under nitrogen for 1-1 hour and then cooled in an ice bath. The mixture is then acidified with an excess of a saturated aqueous solution of potassium dihydrogen phosphate. Ether is added, and the product is extracted several times with an aqueous solution of sodium hydroxide. The extracts are extracted back with ether, acidified with cold 2.5 N HCl and then extracted with methylene chloride. The methylene chloride extracts are washed with aqueous saturated sodium chloride solution, dried over magnesium sulfate and then evaporated to dryness. The foam formed gives a strong ferric chloride reaction and is recrystallized with ether-petroleum ether, whereby 17a, 20 , 2 0 , 21-bis(methylenedioxy)-118-formyloxy-2-hydroxymethylene-16a-methyl-4-pregnen-3-one can be obtained. This compound exhibits infrared absorption properties corresponding to A-ring hydroxymethylene, which structure is in agreement with the ultraviolet absorption in alkaline methanol, X CH 3 OH= 242 my and 357 my. Furthermore, the compound shows a strong maximum in the infrared region at 5.84 - 5.85 my and likewise at 8.5 my. These maxima are characteristic of 11 -formate.

To 1.433 g of 17a,20,20,21-bis(methylenedioxy)-11B-formyl-oxy-2-hydroxymethylene-16a-methyl-4-pregnen-3-one, suspended in 18

ml of absolute ethanol, 0.45 ml of phenylhydrazine is added, and the mixture is refluxed for 40 minutes under nitrogen. On cooling, 17a,20,20,21-bis(methylenedioxy)-11a-formyloxy-16a-methyl-1'-phenyl-(3,2-c)-pyrazole-4-pregnene precipitates.

17a,20,20,21-bis(methylenedioxy)-11B-formyloxy-16a-methyl-1'-phenyl-(3,2-c)-pyrazole-4-pregnene (720 mg) is heated on a steam bath with 24 ml 60 % aqueous solution of formic acid in approx. 30 minutes. The excess of the reagent is distilled off in a vacuum on a water bath at approx. 50° C. The evaporation residue is rinsed 4 times with n-hexane and then dried at 60° C in a strong vacuum, whereby a solid mixture of 113,17a,21-trihydroxy-16a-methyl-1'-phenyl-(3, 2-c)-pyrazol-4-pregnen-20-one and 118>17a,21-trihydroxy-16a-methyl-1'-phenyl-(3,2-c)-pyrazol-4-pregnen-20-one - format.

500 mg of this crude product is dissolved in 2.4 ml of pure methanol and reacted with 0.9 ml of a 1.3 3 N solution of sodium methoxide in methanol at room temperature under a nitrogen atmosphere for 10 minutes. This alkoxide is neutralized with acetic acid, and the mixture is evaporated to dryness and rinsed with n-hexane. The evaporation residue is washed with water, filtered and dried to constant weight, whereby 118,17a,2l-trihydroxy-16a-methyl-1'-phenyl-(3,2-c)-pyrazol-4-pregnen-20-one is obtained. The compound is isomerized to the 2' compound by conversion to the hydrochloride which melts at 14 3 - 14 5°C.

Example 4

To 200 mg of 17a,20,20,21-bis(methylenedioxy)-ll8-hydroxy-2-hydroxymethylene-16a-methyl-4-pregnen-3-one, prepared as described

know in example 1, in 7 ml of absolute ethanol, put 82 mg of sodium

acetate and then 102 mg of cyclohexylhydrazinoxalate. The mixture is boiled under nitrogen for 1 hour. Insoluble material is removed by filtration. The filtrate is evaporated to dryness. The evaporation residue up-

is dissolved in 3 ml of ether, and the ether solution is washed successively with 2% aqueous sodium hydroxide and then with water to a neutral reaction. The ether solution is then dried over magnesium sulfate, filtered

and evaporated to dryness, thereby obtaining 19 7.7 mg of a yellow substance consisting of 17a,20,20,21-bis(methylenedioxy)-1'-cyclohexyl-16a-methyl-(3,2-c)-pyrazole -4-pregnen-11B-ol, X max = 273 my (e = 165).

150 mg of the above substance is heated under nitrogen

with 5 ml of a 60% aqueous solution of formic acid for approx. 40 minutes. The leaves are evaporated to dryness, and then water is added. The product is extracted with chloroform, and the chloroform solution is washed with saturated aqueous sodium chloride solution, 5% aqueous sodium hydrogencarbonate solution and then with water. The chloroform solution is dried over magnesium sulphate and evaporated to dryness, whereby an evaporation residue of 7.6 mg is obtained. This is taken up in ether containing a little methanol, stirred with 75 mg of activated charcoal, filtered and then evaporated to dryness, whereby lip,17a,21-trihydroxy-16a-methyl-1'-cyclohexyl-(3,2-c)-pyrazole is obtained -4-pregnen-20-on, X ma]<s =

276 my (e = 199).

Example 5

A mixture of 90 mg of 17α,20,20,21-bisCmethylenedioxy)-116-hydroxy-2-hydroxymethylene-16α-methyl-4-pregnen-3-one 5 prepared as described in Example 1, and 0.028 ml of phenylhydrazine is boiled under nitrogen in 1.2 ml of absolute ethanol for 50 minutes. The reaction mixture is evaporated to dryness. Water is added, and the product is filtered off as an amorphous substance which is washed successively with water, dilute acid, water and petroleum ether. The product is recrystallized from methanol, whereby 17a>20,20,21-bis(methylenedioxy)-116-hydroxy-16a-methyl-1'-phenyl-(3,2-c)-pyrazole-4-pregnene is obtained, X ma;ks =

260 my (e = 308).

30 mg of this product is heated on a steam bath with 2 ml

60% formic acid for 35 minutes. The solvents are distilled off in

vacuum, whereupon water is added, and the product is filtered, whereby a mixture of 116,17a,21-trihydroxy-16a-methyl-1'-phenyl-(3,2-c)-pyrazole-4-pregnene-20- on and the 21 format of this. The presence of formate is evident from the infrared absorption at 5.81 and 8.5 y.

500 mg of this crude product is dissolved in 2.4 ml of pure methanol and reacted with 0.9 ml of a 1.3 3 N solution of sodium methoxide in methanol at room temperature under a nitrogen atmosphere for 10 minutes. The alkoxide is neutralized with acetic acid, and the mixture is evaporated to dryness and rinsed with n-hexane. The evaporation residue is washed with water, filtered and dried to constant weight, whereby 116,17a,21-trihydroxy-16a-methyl-1'-phenyl-(3,2-c)-pyrazol-4-preg-nen-20-one is obtained , X ma^g3 = 2.8 - 3.0 y, 5.84 y, 6.13 y, 6.21 y and 6.61 y.

Example 6

To a mixture of 223 mg of 17a,20,20,21-bis(methylene-dioxy)-116-hydroxy-2-hydroxymethylene-16a-methylene-4-pregnen-3-one, prepared as described in Example 1, in 5 ml of absolute ethanol, add 49 mg of sodium acetate and then 95 mg of p-toylhydrazine hydrogen chloride. The mixture is refluxed under nitrogen for 45 minutes. After cooling, a solid is precipitated which is filtered off. The filtrate is evaporated to dryness, and water is added. The product is filtered, washed with water, dilute acid and again with water, until the reaction is neutral, whereby 17a,20,20,21-bis-(methylenedioxy)-16a-methyl-1'-(p-tolyl)-(3 ,2-c)-pyrazole-4-pregnene-II6-0I, X max 262.5 my, (e = 276).

The product is purified by dissolving 2 35 mg of the impure material in 30 ml of methanol and stirring at room temperature with 2 35 mg of activated carbon. The product is filtered, and the filtrate is concentrated and recrystallized, whereby 17a,20,20,21-bis(methylenedioxy)-16a-methyl-1'-(p-tolyl)-(3,2-c)-pyrazole-4-pregnene is obtained -ll-ol, melting point 161 - 163.5° C, U.V. X , 263 my, (e = 329); I.R. 3 y area, 6.15 y, 6.55 y, 9.06 y. 13 mg of the above product is heated on a steam bath with 1 ml of a 60% aqueous solution of formic acid in approx. 3 5 minutes. The mixture is evaporated to dryness, water is added, and the product from filtered, whereby 116,17a,21-trihydroxy-16a-methyl-1'-(p-tolyl)-(3,2-c)-pyrazol-4-pregnen-20-one is obtained, I.R. 2.74 y, 2.8 to 3.0 y,

5.82 y, 6.1 to 6.55 y; UV A max 265 my, (e =355).

Example 7

111.5 mg of 17a,20,20,21-bis(methylenedioxy)-116-hydroxy-2-hydroxymethylene-16a-methyl-4-pregnen-3-one, prepared as described in example 1, is suspended in 2.5 ml ethanol and treated with 24.5 mg of sodium acetate, after which 48.5 mg of p-fluoro-phenyl-hydrazine hydrogen chloride is added. The air in the container is displaced with nitrogen,

and the mixture is heated rapidly to the boiling point. After boiling with reflux for 1 hour, the mixture is evaporated to dryness. The evaporation residue is dissolved in ether, the ether layer is treated 3 times with 2.5 N hydrochloric acid and then 3 times with 2.5 N sodium hydroxide and finally with water. The ether layer is dried over magnesium sulphate, filtered and concentrated to dryness in vacuo. The product is dissolved in methanol and set aside for slow crystallization, whereby 80.9 mg of 17a,20,20,21-bis(methylenedioxy)-116-hydroxy-16a-methyl-2'-(p-fluorophenyl)-4 is obtained as the main component -pregnene-(3,2-c)-pyrazole, melting point 149 - 152° C, X Me?H = 260 (e = 299).

etc. KS

The mother liquor is chromatographed on neutral aluminum oxide and then eluted with a mixture of benzene and n-hexane, whereby a further 44.5 mg of product is obtained, which after recrystallization from methanol melts at 147 - 152° C. 70 mg 17a,20,20,21 -bis(methylenedioxy)-110-hydroxy-16a-methyl-2'-(p-fluorophenyl)-4-pregnene-(3,2-c)-pyrazole is heated on a steam bath with 2 ml of a 60% solution of formic acid in 3 5 minutes. Excess reagent is distilled off in a vacuum using a water bath at approx. 50° C. The evaporation residue is washed carefully with water and then dried at 80° C to form 61.1 mg of evaporation residue. The impure product is dissolved in 3 ml of spectrally pure methanol and reacted with 0.5 ml of a 0.1 N solution of sodium methoxide in methanol at room temperature for 10 minutes. The product, which has a pH value above 11, is neutralized with acetic acid. The mixture is then evaporated to dryness and washed carefully with water, filtered and dried to constant weight, yielding 57.5 mg of 118 »17a,21-trihydroxy-16a-methyl-2 0-oxo-21-(p-fluorophenyl)-4 -preg-nen-(3,2-c)-pyrazole, which has an absorption maximum at 250 m.o.

About. 137 mg of 118,17a,21-trihydroxy-16a-methyl-20-oxo-2'-(p-fluorophenyl)-4-pregnene-{3,2-c)-pyrazole is treated with a mixture of 4 ml of pyridine and 4 ml of acetic anhydride, and the mixture is allowed to stand at room temperature for 18 hours. The solvents are distilled off in vacuum, the evaporation residue is washed with small portions of benzene. After drying, it weighs 120 mg. This residue is chromatographed over silica gel. The fraction eluted with 8:2 petroleum ether:ether is recrystallized from methanol, whereby 113,17a,21-trihydroxy-16a-methyl-2 0-oxo-2'-(p-fluorophenyl)-4-pregnene-(3, 2-c)-pyrazole-21-acetate, with melting point 178 - 184° C. After further recrystallization, a sample melts at 186 - 188° C.

Example 8

To 223 mg of 17a,20,20,21-bis(methylenedioxy)-118-hydroxy-2-hydroxymethylene-16a-methyl-4-pregnen-3-one in 3 ml of absolute ethanol is added 49.2 mg of sodium acetate and then 10 5 mg of p-methoxyphenyl-hydrazine hydrochloride. The reaction mixture is refluxed for 5 minutes, during which time its color becomes dark. The product is filtered off and evaporated to dryness. The residue is dissolved in ether, the solution is filtered and stirred with the residue's own weight of "Darco G-60" (a quality decolorizing charcoal). The filtrate is evaporated to a volume of 1 ml. Petroleum ether is then added, and the product is filtered off, whereby 17a,20,20,21-bis(methylenedioxy)-16a-methyl-1'-(p-methoxyphenyl)-(3,2-c)-pyrazole-4-pregnene is obtained -llB-ol.

In the ultraviolet region of the spectrum: 268 my, (e = 268).

70 mg of this material is heated on a steam bath with 7 ml

60% aqueous formic acid for approx. 40 minutes under a nitrogen atmosphere. The mixture is evaporated to dryness, the residue is added to water and the product is filtered off. The spectrum in the infrared region shows a high peak at 5.84 y (C=0) and a maximum at 8.15 y. In the ultraviolet range: X Vo 266 my, (e = 296).

niciK p

50 mg of this material is purified by dissolving it in acetone and adding 50 mg of "Nuchar C-1000-N" (a quality decolorizing charcoal) to the solution and then filtering it. Petroleum ether is added, and the product crystallizes. After several treatments, a yellow solid is obtained consisting of 113,17a,21-trihydroxy-16a-methyl-1'-(p-methoxyphenyl)-(3,2-c)-pyrazole-4-pregnen-20- on

X mak, p 270 my, (e = 338).

In an alternative embodiment, 49.2 mg of sodium acetate and then 10 5 mg of p-methoxyphenyl-hydrazine hydrochloride are added to 2 33 mg of 17a,20,20,21-bis-(methylenedioxy)-11B-hydroxy-2-hydroxymethylene-16a- methyl-4-pregnen-3-one, after which the mixture is allowed to stand at room- where denotes B-hydroxy or keto, R2 denotes hydrogen, fluorine or methyl, R 3 denotes a-methyl, $-methyl or methylene, R^ denotes hydrogen or acyl, R5 denotes hydrogen, acyl, alkyl, cyclalkyl, arylalkyl or an aryl group which may optionally be substituted with a halogen atom, an alkyl group or an alkoxy group, and X denotes hydrogen or halogen, characterized in that a compound of the general formula: where <R>1<?> R2, R3 and X have the meanings given above, is reacted with an alkyl formate and sodium hydride in an inert atmosphere, whereby a compound of the general formula is obtained: temperature for 5 hours. It is then evaporated to dryness. The residue is dissolved in ether, and the solution is first extracted with a 2.5 N sodium hydroxide solution, then with 2.5 N hydrochloric acid, then with water and finally with a saturated sodium chloride solution. The solution in ether is freed from water with magnesium sulphate, filtered and evaporated to dryness, whereby a residue is obtained which shows a maximum in the ultraviolet region of the spectrum at 270 mp, (e = 258).

The crude product thus obtained is dissolved in 20 ml of methanol while heating, and 50 g of "Nuchar C-1000-N" is added to the solution. The mixture is filtered, and the filtrate is evaporated to a small volume. Water is then added, whereby 75 mg of 116,17a,21-trihydroxy-16a-methyl-1'-(p-methoxyphenyl)-(3,2-c)-pyr-azol-4-pregnen-20-one is separated , which is purified by chromatography in silica gel. The spectrum in the ultraviolet region shows X max 273, (e = 287).

116 The 17a,21-trihydroxy-16a-methyl-1'-(p-methoxyphenyl)-(3,2-c)-pyrazol-4-pregnen-20-one is treated with a mixture of 1.5 ml of pyridine and 1, 5 ml of acetic anhydride, and the mixture is left overnight at room temperature. The solvents are then removed in vacuo, the residue is added to water, and the obtained 116,17a, 21-trihydroxy-16a-methyl-1'-(p-methoxyphenyl)-(3,2-c)-pyrazole-4-pregnene-20- on-21-acetate is separated by filtration. After drying, the compound is dissolved in methylene chloride, a few drops of 2.5 N hydrochloric acid are added to the solution, after which it is evaporated to dryness. The 118,17a,21-trihydroxy-16a-methyl-1'-(p-methoxyphenyl)-(3,2-c)-pyrazol-4-pregnen-20-one-21-acetate hydrochloride thus obtained is soluble in methylene chloride and can be crystallized from acetone.

Claims (1)

Procedure for the production of 17a-hydroxy-20-oxo-4-pregnene-(3,2-c)-pyrazole compounds of one of the general formulas: where R-p R2, R3 and X have the meanings given above, which compound is reacted in an inert atmosphere with a hydrazine of the general formula R5NHNH2, where R5 has the meaning given above, or a salt thereof, whereby a compound of a of the general formulas: where R-p R2> Rg> R^ and X have the meanings given above, which compound, if R^ is hydrogen, if desired is reacted with an acylating agent, an alkyl halide or an arylalkyl halide, whereby the hydrogen is replaced by an acyl, alkyl or arylalkyl -group, after which any 11-keto group, if desired, is reduced to the corresponding 118-hydroxy group, after which the compound is reacted with an acid for cleavage. of the methylenedioxyd group, and the 21-hydroxy compound thus obtained is, if desired, converted into a 21-ester by reaction with an acylating agent.