Process for preparing steroid hormones with pregnane skeleton

The present invention relates to a process for preparing 11,17,21-hydroxy-tribe 4-en-3,20-dione, of formula I:

ch₂-Oh

<img file="RO79971A_D0001.tif" />

The preparation of steroid hormones having a pregnancy structure with free or protected hydroxyl groups is known and successful eggs are used in the preparation of valuable pharmaceutical hormones, such as, hi2 drocortisone, prednisolone, 6-methyl prednisolone etc.

Also known is the protection of the carbonyl group in the ring A, which groups ⁵ is protected as an inhalation salt, which, after bromide re and subsequent re-sequestration, is converted into 21-acetoxy-17-hydroxy-pregna -4- en -3,20- dione (, substance S-21- Reichstein's aetetat), without ¹⁰ a definite product purity, with 79% yield.

In a common method for the preparation of steroid hormones, it departs from the appropriate materials, does it contain the hydroxyl group at position 3, protected by an acetyl group, so as to result in the appropriate functional reactions.

2o the side carbon chain of the molecule and obtaining "Reichstein's substance S".

The price of LEI 13.50 in this tail, the acetyl group is to be hydrolyzed, so as to convert into a carbonyl group, in a separate microbial phase, when precise hydroxyylation at the position takes place in the. a second phase mi- ⁵crobiană,

A disadvantage of this method is that a mixture of two salts is obtained, practically, the first of these salts having a connection ¹⁰ double reactive in ring B and thus unstable during the following phases, which occur in the side chain.

The process according to the present invention removes said disadvantages, by treating 17 α-hydroxyprogesterone with picrolidine, at a molar ratio of about 1: 1, at boiling temperature in methanol medium, then the resulting enamine of formula II;

<img file="RO79971A_D0002.tif" />

ί

j.

RK

Which is then subjected to water heating in?

presence of alkali metal carbonate, at 30 ° C, obtaining the dlon-derivative with the formula 1 V: I

<img file="RO79971A_D0003.tif" />

is treated with perchloric acid at a temperature of 15 ° C - 20 ° C, obtaining the enzyme salt of formula III:

S

IT; ⁴⁵ with ch₃

<img file="RO79971A_D0004.tif" />

OH (IUI

CH2 - Br

<img file="RO79971A_D0005.tif" />

which is reacted with alkali metal acetate at boiling temperature to give 21-acetoxy-17-hydroxy-pregna-4-in-3,20-dion, of formula VI:

ch₂-O-CO * CH₃

<img file="RO79971A_D0006.tif" />

which is brought into contact with bromine at 3 °, 33 ° C, the bromine derivative of formula IV: 55 is obtained which is treated with acetic anhydride at boiling temperature, in the presence of perchloric acid or p-toluenesulfonic acid and ethyl acetate, obtaining diocetates and triacetatu! with formulas VII and VIII:

7997I ch₂-O-CO-CH₃

<img file="RO79971A_D0007.tif" />

<img file="RO79971A_D0008.tif" />

are they subjected to hydroxylation at position 11, by. microbial treatment, unusually,

Following is an example of the embodiment of the process according to the present invention.

g 17 ~ α-hydroxyprogesterone is dissolved, by boiling, in 300 ml of methanol, dried in a stream of nitrogen. Add 4 ml of distilled pyrrole in droplets. After cooling, 70% of the solvent is distilled in vacuo and the enamine thus obtained is filtered. Without drying, this enamine is added to a solution-cooled dry methanol, with a temperature of 15 ... 20 ° C, and perchloric acid (500 ml MeOH-8 ml HCIO).₄), the solution is quenched at room temperature and diluted with an additional 250 ml of dry methanol and heated for a few minutes until the boiling point of the solvent is reached -1. The perchlorate precipitate is completely dissolved, the solution fading. After cooling to a temperature of 3O ..- 33 ° C, 2 ml of bromine dissolved in 50 cm are added dropwise.³ dry methanol. Without separating the bromine derivative, the protective g-rupture is removed by adding 120 ml of water and 10 g of K2CO3 dissolved, previously, in 30 ml of water. This alkaline treatment of the material is done for about one hour at 30 ° C under nitrogen current. Most of the alcohol is distilled in vacuo (boiling point up to 30 ... 35 ° C) and the residue thus obtained is diluted with 50 ..., 60 times the quantity of cold water. A white precipitate of 21'bram-17'hydroxy-pregna ~ 4-en-3,20-dion is obtained, which is filtered, then washed well with cold water and dried in warm air at room temperature. 50 ° C. The obtained compound, with a point of

Boil 21O ... 215 ° C, dissolve in 500 ml acetone containing 5 g of potassium acetate and the solution is boiled with reflux during

2 .. .3 fiAfter distilling most of acetone, dilute egg yolk

50 .. .60 times the amount of ice water and the material is filtered and washed with water. "Reichstein's S-21-acetate substance thus obtained dries and is grass-fed with

4 .. .5 times the amount of methanol added, the aqueous egg is diluted to a greater amount of water, after which it is cooled to 0 ° C and filtered. 21- Acetoxy-17- hydroxy- preg-na -4- en-3,20- dion used a melting point of 240 ° C. The yield is 9 g.

g "Reichstein's -S- 21 -acetate is dissolved in 20 ml of methylene gold, 10 ml of acetic anhydride and 10 ml of a catalytic mixture of ethyl acetate, containing 1% of p-toluenesulphonyl aqueous solution or perchloric acid. The mixture is boiled to obtain a solution. After a time of 3 ... 4 h, Ocetilation is complete and a mixture of two products is obtained - Reicshstein's triacetate -S- 3,17,21 and the -S-17,21 diacetate from Reichstein, After cooling the solution to a temperature of 30 ° C, add 100 ml of methanol. Transesterification of free acetic anhydride in ethyl ester takes place, in the presence of methanol and acid catalyst, for 3 to 4 hours at room temperature. The solvent is distilled, until a thick crystalline residue is obtained, which is diluted with water, thereby obtaining white crystals of, respectively, two Reichstein's "substance-S" acetate derivatives, containing both hydroxyl group protected by an acetyl radical at position 17- After filtering and drying the crystalline mass, about 10 g of product suitable for microbial hydroxylation at position 11 are obtained.

The purpose of the present invention is to develop a method for the preparation of steroid hormones or pregnancy structure, through simplified technology and they have high purity - the product thus obtained, mute.

The method, according to the present invention, for the preparation of steroid hormones with pregnancy structure, which uses a protection of the oarbonyl group in positions 3 in the molecule with steroid structure, by transforming this cleavage into a re of the enzyme, it consists in that the enamine is precipitated, at a low temperature, in an acid solution and the mixture of salts thus obtained is transformed, by heating it, into an indefinite enamine salt, having a single peak for double bonds conjugated in the spectrum! inf-ra-red is 1,610 cm^-1, after which the bromination and hydrolysis of the protecting group of position 7997I 3 takes place in&gt; a reaction vessel, the protection of the hydroxyl group of position 17 being made by acetylation, using acetic anhydride and acid catalyst, in the presence of a free carbon group at position 3 and of the acetyl group at position 21, subjecting the molecule thus obtained to a single microbial treatment for hydroxylation at position 11 thereafter.

This method is executed by protecting the carbon group at position 3 in the molecule with steroid structure, the group being conjugated to a double bond, when an indefinite product is obtained, which is stable during the following reactions, which occur in the carbon chain. laterally, after which a protection of the hydroxyl group at position 17 in the molecule takes place, thus obtaining a product that is suitable for the microbial treatment of a steroid hormone.

In the method according to the present invention, a C = C and C-N double bonded conjugate system salt is obtained, which bonds are stable during electrophilic reactions, and the protection of the hydroxyl group at position 17 is made by acetylation.

In the conditions of preparation of the enzyme salt starting from the enamine, the molecules having double bonds in the ring B with steroid structure remain in the product. A peak for a double bond at 1,610 cm^-1is found in the infrared spectrum of the obtained product, this peak having a double bond C = C, conjugated with a double bond C—^_N, as well as a peak at 1 655 cm^-1, which corresponds to an isolated double bond C = C.

The last peak confirms the presence of molecules with double bonds in the ring B- The passage of this double bond in the ring A is done by conferring additional energy to the system, when a salt is obtained which contains only a peak with double bonds at 1,610 cm.¹, ie the product has only a conjugate system of double bonds C'-N and C = C. This is also confirmed by the MRI spectrum.

The salt prepared according to the method of the present invention provides, in a quantitative manner, the subsequent reactions, that is, bad bromide and acetylation. The bromine derivative of the enzyme salt (21-bromo-17-hydroxy-pregna -4- en-3,20- dion), according to the present invention, has a melting point

219.,. 220 ° C. Bromide is converted into a "Reichstein's S-21-acetate substance (21-acetoxy-17- hydroxy-pregna -48)

-en-3,20-dion) and is treated with an acetylation mixture, to protect the hydroxyl group at position 17. This protection is done using an acetylation mixture, composed of acetic anhydride in a solvent, in the presence of a catalytic mixture, composed of perchloric acid in ethyl acetate, avoiding the use of expensive trifluid anhydride at times that are usually used in such cases. The conditions are thus chosen, once the acetylation of the hydroxyl group at position 17 is made quantitatively, without any change in the stereochemistry of this group, and the carbon group at position 3 with the steroid structure of the molecule remains free, or is converted to enolacetate. The latter does not in any way influence the execution of the microbial transformation for 11-beta-hydroxylation, since, under the conditions of this hydroxylation, it is immediately bidrolized and thus releases the hydroxyl group, which is conjugated with a double bond.

The process according to the present invention, for the protection of the hydroxyl group at position 17, in the presence of the carbon group at position 3, has the advantage that it provides the hydroxylation at position 11, by performing a single microbial treatment,

The advantages of the present invention are the following:

- a product of a salt with proven enzyme structure is obtained, allowing quantitative transformations to be performed during the separate phases for the preparation of Reichstein's "substance-S";

- in most cases, the separation of intermediate products of synthesis of "Reichstein's S-substance" is avoided;

- the synthesis is performed with reduced solvent consumption, force, processing and time;

- it is a cheap method of acetylation of the hydroxyl group at position 17, in the presence of both a free carbon group at position 3 and an acetyl group at position 21, without any modification of lateral cationic stereochemistry;

- the microbial treatment of Reichstein's S-substance protected for hydroxyls at position 11, etc. it is done in a safe phase.