NL8703151A - PROCESS FOR THE PREPARATION OF 16-DEHYDRO-20-OXOPREGNAND DERIVATIVES. - Google Patents

Description

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NL 34733-Kp / vD

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Process for the preparation of 16-dehydro-20-oxopregnan derivatives.

The invention relates to a new process for the preparation of 16-dehydro-20-oxopregnane derivatives.

Since 1950, 16-dehydro "20-oxopregnane derivatives have been used as intermediates in the synthesis of corticosteroids. P. L. Julian et al .: J. Am. Chem. Soc. 72, 5145 (1950) _ /

They can be advantageously prepared by the oxidative chemical degradation of various sapogenins, e.g. diosgenin, tigogenin or hecogenin / R.E. Marker et al .: J. Am. Chem.

Soc. € 1,392 (1939); ibid. 62, 518 (1940); ibid. 69, 2167 10 (1947) / as well as from the aglycones of some steroidal alka loids, eg solasodine or tomatidine / Ϋ. Sato et al .: J.

Org. Chem. 22, 1496 (1958) 7

From the mid-1960s, in addition to sapogenins and steroidal alkaloids, plant-origin sterols, in particular sitosterol, have been used as starting materials in the synthesis of drugs, due to their lower price and easier availability.

It is known that 3-oxo-23,24-dinor-4,17 (20) -chola-dien-22-acid (U.S. Patent No. 3,994,933) and 20a-hydroxy-3-oxo-23,24 Dinor-4,17 (20) -choladiene-22-acid (British Patent No. 2,098,218) are prepared by the partial microbial side chain degradation of sterols of animal or vegetable origin.

Intermediates of a pregnanskeleton have been attempted to prepare from sterol degradation products with 23,24-dinorcholanskeleton for the synthesis of corticosteroids.

It has been found according to the invention that 3-oxo-23,24-converted dinor-4,17 (20) -choladiene-22-acid can be converted by hydrogen peroxide into 4,16-pregnadiene-3,20-dione and 9a Hydroxy-3-oxo-30 23,24-dinor-4,17 (20) -choladiene-22-acid in the new compound 9a-hydroxy-4,16-pregnadiene-3,20-dione in high yield in a neutral or alkaline aqueous medium in the presence of oxo acids of transition metals (tungsten, molybdenum, vanadium, titanium).

35 This type of transformation has not been found in the literature. It allows the preparation of 16-dehydro-20-oxo-pregnan-.8703151-2-κ & derivatives, which can advantageously be used as intermediates in the synthesis of corticosteroids from natural sterols in high yield.

First, the 3-oxo-23,24-dinor-4,9 (11), 17 (20) -cholatriene-22-acid, not described in the literature, was prepared from the known 9a-hydroxy-3-oxo-23, 24-Dinor-4,17 (20) -chola-dien-22-acid by eliminating the 9a-hydroxy group. The presence of the 9 (11) double bond in this molecule paves the way for the formation of 11f3-hydroxy or 11-oxo group, characteristics of the corticosteroid drugs, or for the introduction of a halogen substituent in the position C-9, known for increasing the anti-inflammatory effect of corticosteroids.

Microbial dehydrogenation with Arthrobacter 15 simplex also introduced a double bond in the 3-0X0-23,24-dinor-4,9 (11), 17 (20) -cholatri-22 acid in position 1, which was common in corticosteroids.

The new method, suitable for the conversion of 23,24-dinorcholanic acids, which are unsaturated at position 17 20 (20) into compounds with a pregnan skeleton, was used for the preparation of the well-known 4.9 (11), 16-pregnatriene -3,20-dion [s. Bernstein: J.Am.Chem. Soc. 8_1_, 4956 (195 ^ 7 from 3-0X0-23,24-dinor-4,9 (11), 17 (20) -cholatrien-22-acid and the new intermediate of corticosteroid synthesis, 1,4,9 (11) 16-25 pregnatetraene-3,20-dione from 3-oxo-23,24-dinor-1,4,9 (11), 17- (20) -cholatetraene-2-2-acid.

It may be advantageous to transform the 3-oxo group during the transformation of 16-dehydro-20-oxo-pregnan derivatives prepared from 3-0X0-23,24-dinor-4,17 (20) -choladiene-22 acid or protect derivatives that are substituted on the sterane skeleton in the corticosteroids. Namely, in this case, an epoxide can be selectively formed on the 16 double bond, while the 16a, 17α-oxide derivative is easily transformed into the 17α-hydroxy compound with the characteristic 35 17α-hydroxy aspect of corticosteroids /P.L. Julian et al .: J.Am.Chem.Soc. 72 ,, 5145 (1950) _ / - So the 3-oxo group of the steroids with a 3-oxo-23,24-dinor-4,17 (20) -choladiene-22-acid structure is protected by blocking groups (oximes , ketals, enol ethers), while the resulting derivatives become. 87 0 3 1 5 1: - 3 - * converted to the corresponding 16-dehydro-20-oxopregnander derivatives.

Based on the above set forth, the invention relates to a process for the preparation of 5 16-dehydro-20-oxopregnane derivatives, wherein a steroid having 17 (20) -dehydro-23,24-dinorcholan-22-acid structure or a salt thereof, it is reacted with hydrogen peroxide in a neutral or alkaline medium in the presence of oxalic acid salts of transition metals as catalysts.

In the process of the invention, any roid with the 23,24-dinorcholan-22-acid structure with a double bond at the 17 (20) position can serve as starting material.

For the preparation of the intermediates of 16-dehydro-20-oxopregane structure, which are most suitable for the synthesis of natural corticosterol hormones and drugs, it is preferable to modify the 17 (20) -dehydro-23,24-dinorcholanskeleton before their use in the method according to the invention, such that the introduction of the 17a and 21-hydroxy-20 groups, characteristic of the corticosteroids, is promoted. From an economic point of view, it is advantageous to develop a synthesis strategy in which the characteristic structural elements of the designed corticosteroid are easily introduced into the skeleton of dinorcholanoic acids, which can be prepared in an expensive manner by a microbial method.

According to a preferred embodiment of the present invention, an amount of 20-50 mole% ammonium or alkali metal salt of the transition metal oxoacids used as catalysts is first added to an aqueous solution of the formed salt, optionally in situ with an inorganic or organic base, preferably with sodium hydroxide, of 17 (20) -dehydro-23,24-dinorcholanoic acid, which is used as starting material, after which a 30% aqueous hydrogen peroxide solution in a 5 to 50 fold molar excess is added to the reaction mixture .

It is preferable to use ammonium paramolybdenate or sodium tungstate as catalyst.

Unlike the dinorcholanic acid salts used as the 8703151-4-t starting material, the products with a 16-dehydro-20-oxopregnanskeleton are practically insoluble in water and precipitate out of the reaction mixture.

The products can advantageously be purified by recrystallization. The mother liquor components can be purified by column chromatography or by preparative thin layer chromatography.

The structure of the products prepared by the present method was confirmed by ultraviolet, infrared, red, H-NMR and mass spectroscopic methods.

The method of the invention is further illustrated by the following non-limiting Examples.

EXAMPLE I

Preparation of 9a-hydroxy-4,16-pregnadiene-3,20-15 dione from 9a-hydroxy-3-oxo-23,24-dinor-4,17 (20) -choladiene-22-acid_ 1076 mg (3mmol) 9a-Hydroxy-3-oxo-23,24-dinor-4,17- (20) -choladiene-22-acid was dissolved in a mixture of 30 ml water and 3 ml 1 N sodium hydroxide. Then 531 mg of ammonium paramolybdenate tetrahydrate was dissolved in 6 ml of water, the pH was adjusted to a value of 8.0 by adding concentrated ammonium hydroxide, and the two solutions were combined. To this reaction mixture, which has a pH of 8.5, 20 ml of 25% hydrogen-25 peroxide at room temperature was added dropwise over 2.5 hours. Foaming of the reaction mixture was prevented by the addition of a few drops of dichloromethane. After the completion of the reaction, the mixture was allowed to stand at 45 ° C for 30 min to remove the dichloromethane,

30 after which the mixture was cooled to room temperature. The precipitated product was filtered off and dried. Yield: 650 mg, 9a-hydroxy-4,16-pregnadiene-3,20-dione was recrystallized first from acetone and then from benzene. Mp: 186 to 192 ° C

Ultraviolet spectrum (ethanol): Amax 242 nm (ε = 25,400) infrared spectral data (KBr): 3530, vc = 0 1665, 1650, vc = c 1610, 1585 cm -1 H NMR spectral data (CDCl3, δ, TMS): 6.75 m (H-16), 5.90 s (H-4), 2.25 s (3H-21), 1.30 s (3H-19), 40 0.95 s (3H -18) ppm.

, 8703151 4 - 5 -

Analysis: Calculated Found C 76.79% 76.67% H 8.59% 8.54%

EXAMPLE II

5 Preparation of 4.9 (11), 16-pregnatriene-3,20-dione from 3-0X0-23,24-dinor-4,9 (11), 17 (20) -cholatriene-2 2-acid 1703 mg (5 mmol) 3-oxo-23,24-dinor-4,9 (11), 17 (20) -cholatrien-22-acid was dissolved in a mixture of 50 ml 10 water and 5 ml 1 N sodium hydroxide. Then 885 mg of ammonium paramolybdenate tetrahydrate was dissolved in 15 ml of water, the pH of the mixture was adjusted to a value of 7.5 by adding concentrated ammonium hydroxide, and the two solutions were combined. To this reaction mixture, which had a pH of 8.0, 15 ml of a 25% aqueous hydrogen peroxide solution (110 mmol) was added dropwise at room temperature over a period of 2 hours. The product begins to precipitate during this period of time, after which the precipitated product is filtered off and then dried. Yield: 975 mg of crude 4.9 (11), 16-pregnatriene-3,20-dione, which was recrystallized first from acetone and then from methanol.

Mp: 202 to 205 ° C

IcJjy = + 237 ° (c = 1, chloroform) 25 Preparation of the starting material 3-oxo-23,24-dinor-4,9 (11), 17 (20) -cholatriene-22-acid took place by 1792 mg ( 5 mmol) 9a-hydroxy-3-oxo-23,24-dinor-4,17 (20) -choladiene-22-acid to be dissolved in 18 ml of dichloromethane, after which the resulting solution is dissolved at -5 ° G under stirring 1.08 ml of chlorosulfonic acid was added dropwise while stirring was continued at that temperature for 30 min. Then, with stirring, 22 ml of water was added to the reaction mixture, followed by separation of the layers formed. The water layer was extracted twice with 10 ml of dichloromethane. The dichloromethane extracts were combined and evaporated under reduced pressure. The residue, 184 g, was purified by preparative thin layer chromatography (developing solvent: benzene acetone 8: 2). The resulting chromatographically pure product was dissolved in 30 ml of methanol, after which 0703151-6 ml of 2 ml of 10% methanolic acid was added. This acidic methanolic solution was diluted with 120 ml of ethyl acetate and the mixture was washed twice with 25 ml of water followed by evaporation under reduced pressure. Yield: 1.44 g of 3-0X0-23.24-dinor-4.9 (11), 17 (20) -cholatrien-22 acid, which was recrystallized from methanol.

Mp: 238 to 239 ° C

Ultraviolet spectrum (ethanol): λ 236 nm max

Infrared spectral data (KBr): V 3400-2400, UH _ 1 10 Vc = o1675 (COOH and 3-keto), v 1610 cm 1 1 H-NMR spectral data (CDCl ^, TMS): 5.70 s (H- 4), 5.50 m (H-11), 2.00 s (3 H-21), 1.30 s (3 H-19), 0.90 s (3 H-18) ppm Mass spectral data: M + * 340, 15 m / z: 340, 325,307,295,227,213,105,91.

EXAMPLE III

Preparation of 4,16-pregnadiene-3,20-dione from 3-oxo-23,24-dinor-4,17 (20) -choladiene-22-acid-1028 mg (3 mmol) 3-oxo-23.24- dinor-4.17 (20) -chola-20 dien-22 acid was dissolved in a mixture of 30 ml of water and 3 ml of 1 N sodium hydroxide. 160 mg (0.5 mmol) of sodium tungstate dihydrate in 1 ml of water were added to this solution. Then, 4.0 ml of a 30% aqueous hydrogen peroxide solution was added dropwise to the reaction mixture at 60 ° C with stirring over 1 hour. Heavy foaming was eliminated by adding a few drops of methyl ethyl ketone. The mixture was then stored at 5 ° C overnight. The precipitate was filtered off and dried. Yield: 623 mg of 4,16-pregnadiene-3,20-dione, which was recrystallized from acetone for analytical purposes.

Mp: 186 to 189 ° C

/ oC_7d = + 175 ° (c = 0.9, chloroform)

Ultraviolet spectrum (ethanol): lmax241 nm (£ = 28,100) 35 Infrared spectrum (KBr): v 1650, 1680, v__p1585, 1615 cm

Analysis: Calculated Found C 80.72% 80.90% H 9.03% 9.12%. 61 ü i 1 * j 1 - 7 - s

EXAMPLE IV

Preparation of 1,4,9 (11), 16-pregnatetraene-3,20-dione-from 3-OZO-23,24-dinor-1,4,9 (11), 17 (20) -cholatetraene -22- acid 5 1015 mg (3 mmol) 3-oxo-23,24-dinor-1,4,9 (11), 17 (20) -cholatetraene-22-acid was dissolved in a mixture of 30 ml water and 3 ml 1 N sodium hydroxide. 160 mg (0.5 mmol) of sodium tungstate dihydrate in 1 ml of water were added to this solution. Then, 3.2 ml of 25% aqueous hydrogen peroxide solution was added to the reaction mixture over a period of 10 1 h at 60 ° C with constant stirring. The reaction mixture was then cooled to room temperature, the precipitate formed was filtered off and then dried. 534 g of crude 1,4,9 (11), 16-prenatetraene-3,20-dione 15 were obtained, which was then purified first by preparative thin layer chromatography (adsorbent: 2: 1 mixture of

Kieselgel G and Kieselgel 60 HF254 + 366 'FEj ^ NAL, Budapest; developing solvent: 4: 1 mixture of benzene and acetone), followed by an additional two recrystallization from benzene.

Mp: 204 to 20S ° C

Ultraviolet spectrum (ethanol): λ max240nm (ε = 24,300) Infrared spectral data (KBr): vc = o1670, 1660, vc = c 1630, 1610, 1590 cm “1 1H-NMR spectral data (CDC13, δ, TMS): 7 .20 25 (1H-1), 6.30 (1H-2), 6.05 (1H-4), AMXm (J1 2 = 12 Hz, J2 4 = 2 Hz, J = 0 Hz), 6.70 t (1H-16), 5.60 m (1H-11), 2.30 5Γ (3Η-21), 1.45 s (3H-19), 0.95 s (3H-18) ppm Mass spectral data : M + * 308 30 m / z: 308, 293, 265, 172, 157, 121, 91, 43.

Analysis: Calculated Found C 81.78% 81.70% H 7.84% 7.74%

Preparation of the starting material 3-oxo-23.24-35-donor-1,4,9 (11), 17 (20) -cholatetraene-22-acid.

10 ml aliquots of an Arthrobacter simplex culture, induced by 4-androsteen-3,17-dione to form r 8 7 0 5 15 1 «rf - δ - t '3-oxo-steroid-A-dehydrogenase enzyme, were weighed under sterile conditions in ten 500 ml Erlenmeyer flasks. Then each culture was diluted with 90 ml of 1% (w / w) aqueous 3-cyclodextrin solution. Then 100 ml of 3-ÖXO-23,24-dinor-4,9 (11), 17 (20) -cholatrien-22-acid dissolved in 2 ml of ethanol was added to each culture, which culture was then kept for 2 days shaken on a rotary shaker at 37 ° C. The cultures were then combined, their pH adjusted to 2 using 2N sulfuric acid, and the fermentation broth extracted three times with 200 ml of ethyl acetate. The ethyl acetate extracts were combined and evaporated under reduced pressure. The 960 mg of crude product thus obtained was purified by preparative thin layer chromatography in a developing solvent of benzene acetone (8: 2). The 710 mg of chromatographically pure product was dissolved in 20 ml of methanol, after which 1 ml of 10% hydrochloric acid in methanol was added at 0 ° C. The acid solution was then diluted with 100 ml of ethyl acetate, followed by washing twice with 25 ml of water and evaporation under reduced pressure. The resulting product, 3-oxo-23,24-dinor-1,4, -9 (11), 17 (20) -cholatetraene-22-acid, was recrystallized from methanol.

Mp: 240 to 244 ° C

Ultraviolet spectrum (ethanol): λ 235 nm max 25 Infrared spectral data (KBr) 3600-2500,

Uh vc = 0 1690 (COOH), 1665 (3-keto), vc = c 1630, 1610 cm "1 1 H-NMR spectral data (CDCl3, δ, TMS): 7.20 (H-1), 6, 30 (H-2), 6.10 (H-4), AMXm (J1 2 = 10 Hz '30 J2 4 = 2 Hz, J1 4 - 0 Hz), 5.50 m (H-11), 1, 95 s (3H-21), 1.40 s' (3H-19), 0.95 s (3H-18) ppm Mass spectral data: M + * 338 m / z: 338, 323, 310, 211, 165, 145, 121, 91.

EXAMPLE V

Preparation of 3-methoxyimino-4,9 (11), 16-pregnatri-an-20-one from 3-methoxyimino-23,24-dinor-4,9 (11), 17 (20) -cholatriene-22- acid 1109 mg (3 mmol) 3-methoxyimino-23,24-dinor-4,9 (11) -, 8703151-9 - 17, (20) -cholatrien-22-acid was dissolved in a mixture of 25 ml water, 3 ml 1 N sodium hydroxide and 3 ml dichloromethane. To this solution was first added 500 mg (1.5 mmol) of sodium tungsten hydrate in 3 ml of water. Then 5 ml of 25% aqueous hydrogen peroxide solution was added dropwise to the reaction mixture over two hours and at 55 ° C with constant stirring. During the addition, the product precipitated under heavy foaming. The precipitate formed was filtered and dried. Yield: 967 mg of 3-methoxyimino-4,9 (11), 16-pregnatriene-20-one, a mixture of E and Z isomers.

Infrared spectral data (KBr): vr_n 1659, vc = c 1620 cm

Analysis: Calculated Found 15 C 77.84% 77.61% H 8.61% 8.59% N 4.13% 4.53%

Preparation of the starting material 3-methoxyimino-23,24-dinor-4,9 (11), 17 (20) -cholatrien-22-acid 20 2.04 g (6 mmol) 3-0X0-23.24- dinor-4.9 (11), 17 (20) -cholatrien-22-acid and 0.55 g (6.3 mmol) of methoxyamine hydrochloride were stirred in 15 ml of pyridine at room temperature for 20 hours. Then the reaction mixture was poured into 60 ml of water and then extracted three times with 20 ml of dichloromethane. The combined extracts were evaporated under reduced pressure, after which traces of residual pyridine were removed by azeotropic distillation, first with toluene and then with methanol.

Yield: 2.13 g of 3-methoxyimino-23,24-dinor-4,9 (11), 17 (20) -30 cholatrien-22 acid.

EXAMPLE VI

5.9 (11), 16-pregnatriene-3,20-dione-3-ethylene ketal 1920 mg (5 mmol) 3-oxo-23,24-dinor-chola-5,9 (11), 17 (20), Triene-22-acid 3-ethylene ketal was dissolved in a mixture of 8.6 ml of methanol, 4.3 ml of methyl ethyl ketone, 5.2 ml of 10 M sodium hydroxide and 86 ml of water. 0.21 g of sodium tungstate dihydrate in 4.3 ml of water were added to this solution.

V / w v i ~ i

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Then 12.9 ml of a 30% aqueous hydrogen peroxide solution was added dropwise over an hour at 60 ° C with constant stirring. The reaction mixture was then heated to 85 ° C to remove organic solvents, then the reaction mixture was slowly cooled and stored at 5 ° C overnight. Yield: 1.01 g (60%) 5.9 (11), 16-pregnatriene-3,20-dione-3-ethylene ketal for analytical purposes, the methanol was recrystallized.

Mp: 210 to 214 ° C

10 Ultraviolet spectrum (ethanol) :! 239 nm (ε = 9600) «t ΙΠ3.2 £ H-NMR spectral data (CDC13, 6, TMS): 5.45 m (1H-6, 1H-11), 6.70 t (1H-16), 2.25 s (3H-21), 1.20 S (3H-19), 0.80 (3H-18)

Analysis: Calculated Found 15 C 77.92% 77.66% H 8.59% 8.29%

Preparation of the starting material 3-oxo-23,24-di-nor-5,9 (11), 17 (20) -chol ± rien-22-acid 3-ethylene-ketal 20 1022 mg (3 mmol) 3-oxo -23.24-Dinor-4.9 (11), 17 (20) -cholatriene-22-acid was dissolved in 10 ml of dichloromethane, after which 20 mg of p-toluenesulfonic acid, 1 ml of ethylene glycol, and 0.5 ml of trimethyl orthoformate added. The reaction mixture was stirred at room temperature for 4 hours, then heated to 40 ° C until the mixture was concentrated to half its volume. After the addition of one drop of triethylamine, the solution was diluted with dichloromethane, washed with sodium hydrogen carbonate solution and then with water, followed by drying over sodium sulfate and evaporation under reduced pressure. The product was obtained substantially in quantitative quantity and then recrystallized from methanol for analytical purposes.

Mp: 240 to 243 ° C

- 1 35 Infrared spectral data (KBr): v 1701 cm

A C = U

H-NMR spectral data (CDCl 3, δ, TMS): 11.05 (1H, -COOH), 5.45 m (1H-6, H-11), 3.95 s (4H-dioxolane), 1.95 s (3H-21), 1.20 s (3H-19), 0.90 s (3H-18) ppm. 8703151 5 - 11 -

Analysis Calculated Found C 74.97% 75.02% H 8.39% 8.45% 10.8703151

Claims (12)

Process for the preparation of 16-dehydro-20-oxopregnane derivatives, characterized in that a steroid having 17 (20) -dehydro-23,24-dinorcholan-22-acid structure or a salt thereof is reacted with hydrogen peroxide in neutral or alkaline medium in the presence of oxo acids of transition metals as catalyst. Process according to claim 1, characterized in that 3-oxo-23,24-dinor-4,17 (20) -choladiene-22-acid is used as starting material. Process according to claim 1, characterized in that 9a-hydroxy-3-oxo-23,24-dinor-4,17 (20) -choladiene-22-acid is used as starting material. 4. Process according to claim 1, characterized in that 3-oxo-23,24-dinor-4,9 (11), 17 (20) cholera-triene-22-acid is used as starting material. Process according to claim 1, characterized in that 3-oxo-23,24-dinor-1,4,9 (11), 17 (20) -choro-latetraene-22-acid is used as starting material. 6. Process according to claim 1, characterized in that 3-methoxyimino-23,24-dinor-4,9 (11), 17 (20) -cholatrien-22-acid is used as starting material. 7. Process according to claim 1, characterized in that 3-oxo-23,24-dinor-5,9 (11), 17 (20) -chromatriene-22-acid 3-ethylene ketal is used as starting material material. Process according to claim 1, characterized in that ammonium paramolybdenate tetrahydrate is used as a catalyst. 9. Process according to claim 1, characterized in that sodium tungstate dihydrate is used as the catalyst. 10. 9a-hydroxy-4,16-pregnadiene-3,20-dione. 11. 1,4,9 (11), 16-pregnatetraene-3,20-dione. 12. 3-methoxyimino-4.9 (11), 16-pregnatrien-20-one. 13. 5.9 (11), 16-pregnatriene-3,20-dione 3-ethylene ketal. . 8 7 0 3 1 b ï