FI65784C - NYTT FOERFARANDE FOER FRAMSTAELLNING AV 11BETA-HYDROXI- 4,6- OCH 1,4,6-PREGNADI- OCH TRIEN-3-ONER - Google Patents

Description

rftl / 44. ADVERTISEMENT _ _ Λ ^ Γα ibJ (11) utlAccninosskiupt 6578 4 CW IWtcr.Ui recessed 10 C7 100¾ ^ T ^ (51) K * .j? /Inc.a.^ C 07 J 5/00, 7/00 ENGLISH - FINLAND (21) P * t * nttlh * k «« ine —P »t * nttn * 6lu> ln | 802063. . (22) Hslwmltpllvl — Ameknlnffdag 27.06.80 "^ <23) AWtupiM — Glklch« t * dat 05.02.76 (41) Interpreters fulklMksI - HlvK offuntMj 77 n, Qn P »t« nttl-] · registry managed · .... .....,., _ 'b * od. ".' *> ÄETÄS 30.03.8¾ (32) (33) (31) towHwn it ** prion ** 18.02.75 USA (US) 5502« * 5 (71) Syntex (USA) Inc., 3 ^ 01 Hi 11 view Avenue, Palo Alto, California 91 * 301 USA (US) (72) Pasquale G. Gallegra, San Jose, California, USA (7¾) Oy Kolster Ab (5¾) New process for the preparation of 11β-hydroxy Δ1 '^ -pregnad i- and triene-3 ~ ones - Nytt förfarande för framstälIning av 1 ψ-hydroxi och A?' ^ - pregnad i - och trien- The present invention relates to a new process for the preparation of 11/8-hydroxy- / v 4 6 14 6 ^ '- and Δ' '-pregnade. 3-oner (62) Divided by application 781185 (publication 65783) -Avdelad frän ansökan 781185 (utläggningsskrift 65783) and trien-3-ones of the formula 65784 ch2r c = o HO 1 x x wherein R is H, OH, an alkyl ether or alkyl ester group having 1 to 6 carbon atoms, R1 is H, OH or An alkyl ester group having 1 to 6 carbon atoms, R is H, Ot-CH 2 or / E-CH 2, X is H, F, Cl or

12 J J

R 1 and R 2 may together form a group C 1 -C 4 O 2 -R 1 2 R 5 in which R and R independently of one another denote hydrogen atoms or a hydrocarbon group having 1 to 4 carbon atoms.

The process of the invention is characterized in that the 3-enol ether is formed by reacting the corresponding 3-keto-Δ steroid with triethyl orthoacetate in the presence of a catalytically effective amount of a strong acid in a solvent consisting essentially of more than about 40% by weight ethanol and less than about 60% by weight. % of a suitable oxidized hydrocarbon, followed by the addition of a Λ and / or Λ 'bond, followed, if desired, by the hydrolysis of the possible ester protecting group in a manner known per se.

2

When preparing active steroid compounds for use, for example, as anti-inflammatory drugs, a readily available compound must often be used as a starting material, followed by steps which may include reacting one portion of the compound to form a protecting group and then reacting the other portion as desired. Thus, when using such a process, it is often necessary to carry out extensive series of steps, and there is a certain loss in each step, as a result of which the overall yield of the process may be considerably reduced. Thus, researchers in the field of steroid chemistry are constantly working to develop more efficient reaction methods to improve the overall yield by reducing the number of steps required in the reaction sequence, increasing the yield of each separate step, or using both methods. The overall yield can be improved either by developing a process in which essentially the entire amount of starting material is reacted to form the desired product or to minimize the number of side reactions.

Among the many reaction sequences used to form 6-halo or N'-pregnatrienes, the conversion of a cortisol-type compound having a 3-oxo-A group to an enol ether (i.e., 3-alkoxy-A ') is an important step. intermediate 3) by reacting the 3-keto-A steroid with a lower alkyl orthoformate in a suitable solvent such as dioxane in the presence of an acid catalyst such as p-toluenesulfonic acid. However, when using a readily available compound such as cortisol (hydrocortisone; 11 / 3.17 Ot, 21-trihydroxy-3,20-dioxypregn-4-ene) having a reactive hydroxy group at positions 21 and 11/3, it has previously been shown to be more preferable. that cortisol (Formula A below) is first reacted with formaldehyde and methylene chloride in hydrochloric acid to form the bis-methylene dioxide (BMD) compound (Formula B below).

CH 2 OH 0 - I H 2 <I o - oc = o \ I / CH 2 ηον ^ -χι ^ γ-οη (A) (B) 4,65784 (See, e.g., U.S. Patents 2,888,456 and 2,888,457) .

9 (11)

In order to then prevent the formation of the Δ '' derivative during the reaction with the next lower alkyl orthoformate in the acid, due to the dehydration reaction of the OH group at the 11 / ¾ position and the H in the 9-position, 11 ^ 3-OH is first oxidized e.g. / sulfuric acid in dimethylformamide (DMF), HCl / O! H2C \

X0 - O

(C)

Compound C is then treated with the lower alkyl orthoformate and acid to give the desired enol ether (D), which can then be further treated as necessary.

v <H

o - O v 0v ^ N ^ N '° / CH2 (C) - * (D), where R = lower alkyl 5,657,284 U.S. Pat. No. 3,082,224 suggests that the dehydration problem can be solved by administering cortisol or cortisol. reacting the li-21-ether with a lower alkyl orthoformate in a solvent containing only the corresponding lower molecular weight alcohol and acid catalyst. Using this method, dehydration can be demonstrably reduced to less than 10% and 3-enol ether can be obtained in 65-90% yields.

Similarly, U.S. Patent No. 3,087,927 discusses the formation of a 3-enol ether intermediate of the type mentioned above.

In that series of reactions, the starting material is, for example, 16-hydroxycortisol or 16-hydroxycortisone. According to the patent, these substances can be reacted in the presence of an inorganic acid with an orthoester of formula 3 4 RC (OR) 3 3 4 wherein R is H or lower alkyl (C 1-3) and R is lower alkyl such as methyl and ethyl , for example, a compound of the formula ch2oh C = 0 is obtained as a reaction product

H0 v Jr --- O OR4 V

- ° ^ "r3 WAJ—

R40A / W

In particular, the examples show that the reaction is carried out with trimethyl orthoformate in dioxane in the presence of a small amount of methanol and sulfuric acid. U.S. Patent 3,087,927 makes no mention of the dehydration problem addressed in U.S. Patent 3,082,224.

6 65784 4

In previous methods, it has been suggested that 11-hydroxy-Δ -pregnen-3-ones can be reacted to form the corresponding enol ether using: (1) a trialkyl orthoformate and using dioxane as the major solvent and a lower alkanol (e.g., trimethylformate and methanol as the minor component). or triethyl orthoformate and ethanol), (2) triethyl orthoacetate and, for example, dioxane and, to a lesser extent, ethanol as the main solvent, or (3) triethyl orthoformate with ethanol as the sole solvent.

In order for the reaction to proceed at the desired rate in each of these cases, an acid catalyst is used. It has been found that in the first 9 (11) cases, the main product is the A dehydration product? in the second case, the reagents do not react with each other; and in the third case, dehydration occurs between the 11- and 9-positions and the reaction does not proceed completely. Thus, in each reaction known in the art, the yields of the desired enol ether are low, and when performed in a series of multiple steps, these yields will, of course, reduce the overall yield of the desired final product.

It has now been found that by using the process according to the invention for the formation of 3-enol ether from 3-oxy-β-β / β-hydroxy steroid, the following advantages are obtained: 1) dehydration at the 9 (11) position is practically eliminated completely, 2) thanks to 1) the 11-hydroxy group does not have to be oxidized first to an oxy group for protection purposes, 3) the yield of enol ether increases (due in part to 1) and 2) above, and partly also due to the completion of the reaction ), 4) cheap oxidized hydrocarbon co-solvents such as glyme (ethylene glycol dimethyl ether) can be used with ethanol, 5) for the reaction of steroids with 17O, 21-hydroxy groups, these groups need not be protected using BMD or other methods, and 6 ), the above advantages each contribute to the creation of a method which is simpler than the methods previously known in the art.

7 65784 Other advantages of the method of the present invention will become apparent from the following sections of the specification.

In the process according to the invention, the solvent used is mainly a mixture of ethanol and glyme in a ratio of 50/50 and the catalyst is a strong organic acid such as p-toluenesulfonic acid or trifluoroacetic acid. The process is particularly useful in the preparation of cortisol and cortisol 21-alkyl esters such as 21-acetate.

Preparation of 3-enol ether

It is important that triethyl orthoacetate be used as a reagent in the process of the invention. There is a clear difference between triethyl orthoacetate and its analogous triethyl orthoformate. Triethyl orthoacetate has the formula CH3C (OCH2CH3) 3 whereas triethyl orthoformate has the formula hc (och2ch3)

The chemical side, such as the preparation of aliphatic orthoesters, and general reactions are discussed in "The Chemistry of Aliphatic Orthoesters," American Chemical Society Monograph, HW Post, published by Rienhold, 1943. In general, triethyl orthoacetate can be prepared by several methods, the two most popular being the following equations: (1 ) CH -OC.H_ + 2C.H OH -> NH.Cl + CH, C (OC.H.), 3 || 2 5 25 4 3 253 NH-HCl (2) CH2 = C (OC2H5) + C2H5OH -> CH3C (OC2H5) 3 8 65784

Other methods of preparation can be found on page 40 of the above-mentioned publication. Methods of preparation using the reagents of the first equation above are known from P. Sah's article in the Journal of the American Chemical Society, 50, 516 (1928).

Although the theoretical amount of triethyl orthoacetate 4 required to form the 3-enol ether in the reaction with the 3-oxy-Δ steroid is 1 mole of orthoacetate per mole of steroid, due to the special nature of the reaction, triethyl orthoacetate is generally required at least 2 moles per mole of steroid. , and most preferably at least about 3 moles per mole of steroid are used. However, the molar ratio used is not greater than about 5: 1, since a higher ratio has no particular advantage in terms of reaction rate, etc.

In the process of the invention, it is important that the majority of the solvent in the solvent system used is ethanol, i.e. more than about 40% by weight and most preferably about 50% by weight of the solvent mixture is ethanol. Ethanol can be used up to 100%, although it is preferable to use an additional solvent, as mentioned below. The medium must also be substantially dry, i.e. anhydrous. Useful co-solvents are substances which are freely miscible with ethanol in all proportions. Such substances include oxidized hydrocarbons, for example, aliphatic ethers and cyclic ethers such as glycol ethers, dioxane, tetrahydrofuran and tetrahydropyran. Particularly useful in this regard are dimethylated polyethylene glycols of the formula CH 0 O (CH_CHO) CH-3 2 n 3 where n is 1 to 4. These compounds are commonly referred to as "glyme", i.e. glyme (n = 1), diglyme (n = 2), triglyme (n = 3) and tetraglyme (n = 4). Any of these compounds can be used in the process of this invention alone or in combination as a miscible co-solvent with ethanol. Particularly useful is a mixture of about 50% by weight ethanol and about 50% by weight glyme.

It is further necessary that a catalytic amount of strong organic acid or sulfuric acid be added as a catalyst in the process of this invention. Suitable organic acid catalysts include p-toluenesulfonic acid (PTSA); 2,4-Dinitrobenzenesulfonic acid, trifluoroacetic acid, and other similar acids. P-toluenesulfonic acid or trifluoroacetic acid is mainly used. Catalytic amount of catalyst means the amount required for the reaction to proceed at a reasonable rate. This amount is usually about 0.1 to 20% of the total weight of the steroid and most preferably about 10% by weight.

The reaction conditions under which this reaction can take place are not critical. The temperature can range from 0 to 100 ° C, however, mainly between about 20 and 40 ° C, because at higher temperatures the overall yield decreases due to decomposition reactions. The pressure may be the same as, or lower or higher than, atmospheric pressure. The reaction time depends on the reaction temperature, and is usually 5 minutes to 3 hours, at 20 to 40 ° C for about 1/2 hour.

The reactor used in the process of the invention may be either batch-type or continuous. The reactor is mainly of the batch type.

Steroids to which the method of the invention can be applied include 11-hydroxy-Δ -pregnen-3-ones, in which dehydration can occur at carbon atoms 11 and 9 of the steroids, and thus the steroids useful in the method / structure of the present invention are as follows:

CH R

c = o .ιχτ "

X

1 2 wherein R, R, R and X are as defined above.

4 10 65784 The 6β-halo-Δ -pregnen-3-one intermediate is prepared by first forming the enol ether as mentioned above and then halogenating the 6-position.

The halogenation, which is bromination, or in general chlorination, can be carried out by any 6-position halogenation method known to those skilled in the art. Halogenating agents include N-chlorosuccinimide, N-bromosuccinimide, N, N'-dichlorohydantoin and the like.

In the halogenation step, the 3-enol ether is first isolated from the reagents and solvents of the first step, then the halogenating agent is reacted with the 3-enol ether in a suitable inert solvent under conditions sufficient to cause the formation of the 6-halo-A compound. A suitable inert solvent is a solvent that does not react with the 3-enol ether or halogenating agent in a manner that interferes with the reaction. Useful solvents include oxidized hydrocarbons such as tetrahydrofuran, dioxane and diethyl ether, acetone, acetic acid, or mixtures thereof. The reaction is carried out mainly under neutral conditions, i.e. at a pH of about 7 and a temperature between about -5 ° C and about 25 ° C, most preferably about 0 ° C.

More specifically, the halogenation can be performed by reacting the enol ether with diraethyl N, Ν'-dichlorohydantoin in a buffered acetone solution at a temperature of about -5 ° C to about 5 ° C for 60 minutes.

The process of this invention relates to the total synthesis of 6-halo-Δ'-pregnadiene-11 / 3.17CX, 21-triol-3,20-diones 14 6 and 6-halogen-Δ. '' -pregnatriene-11 / 3.17 OT, 21-triol-3,20-dione, especially 6-chloro compounds, described in U.S. Patent 3,232,965 (Ringold et al.). Both dienes and trienes have an anti-inflammatory effect and low salt retention. The process is also useful in the preparation of 16 01,17 0 * acetonide series compounds and other compounds using the above compounds as starting materials.

11 65784

The process of the invention can be generally illustrated by reference to the following reaction scheme and summary: 1) The first step is the esterification of the starting steroid 21 '(where R * OH and R and R are as defined above) 21-hydroxide to give the corresponding 21-alkyl ester. -ri II.

2) The 21-alkyl ester II is then reacted according to the main object of the present invention with triethyl orthoacetate in ethanol and mainly using glyme and an acid catalyst to form the 3-enol ether corresponding to structure III.

3) The 3-enol ether III is halogenated, i.e. chlorinated or brominated to give, for example, 6β-chloro-Λ 4 ZA -pregnen-3-one corresponding to structure I.

4) The compound of structure I is then reacted with triethyl orthoacetate in the presence of an acid catalyst in ethanol and mainly using glyme to form the enol ether of structure XII.

5a) The 3-enol ether XII can then be further treated to directly form Δ '' -pregnatriene VI1, or 5b) The 3-enol ether XII can first be reacted to form 6 '-pregnadiene VI ".

4 g 5c) The position of JS '-pregnadiene VI "1 is in turn dehydrated by any known method to give the corresponding ^ 1,4,6_pregnatriene VII # 14 6 6a) JS' '-pregnatriene VI' can then be treated in such a way that 21- the alkyl ester decomposes to form the corresponding 21-hydroxy compound XV, wherein Z is a double bond, or 6b) compound VI "can be treated to form compound XV, where Z is a single bond, which compound can in turn be converted to JS '' -pregnatrieeniksi.

12 65784

ch2oii cii2R

9 = 0 1 9 = 0 HO CK3 jL— R OH 1 H0r2 ho 2

CHi (1) I

- -> ^^ ch3J ^ i.

° 0 (2)

II 'II

ch2R ch2r

I I

c = 0 6 = 0 HO ^ CH3Jc "r1 <3) H0 / ^ CH3 Jc- r1 ^^ _

Cl

I III

(4) iH2 * * c = 0 I 2 CH -¾ I 1 c * = 0 - CH3 ^ _. R1 (5a I___1 -> HO 2 R ^ >> vWr _ CH3 CH3CH2O / I% ^> ^ y ^ ( XII) Cl J, V. <6a> 4 vi ·

(5b) / V

y CH2R / ch2oh c = 0 / * ο HO 3 ^ \ "R '* 5c) CH3jL — r1' y Y'-R2 2 CH ^ I _ 0icb)

Cl cl VI ”(XV) 13 6 5 7 8 4

Each step of the overall synthesis is discussed below: 1) In the first step, a compound of structural formula VI ", mainly cortisol, is esterified to form a 21-lower alkyl ester having 2 to 4 carbon atoms in the ester group.

This can be accomplished by any suitable method known to those skilled in the art to esterify the 21-position, usually by reacting the compound with a lower alkyl anhydride in a suitable solvent, for example by reacting cortisol with acetic anhydride in pyridine at a temperature below 30 ° C. The reaction does not form by-products and proceeds to form a compound of formula II which is predominantly cortisol-21-acetate. Instead of acetic anhydride, propionic anhydride or butyric anhydride can be used.

2) In a second step, the 21-ester obtained in step 1) is first isolated and then reacted with triethyl orthoacetate according to the preferred method of the present invention to form the corresponding 3-enolylethyl ether represented by structural formula III. The compound of formula III is essentially the 3-enol ether of cortisol 21-acetate.

Although it is desirable that a compound of structural formula -II ', e.g., cortisol, be first reacted with acetic anhydride to form the corresponding 21-acetate, a compound of structural formula 11' may be reacted directly with triethyl orthoacetate without forming intermediate 21- acetate. When a compound of formula II 'is reacted with triethyl orthoacetate, a small amount, 10-15% of the 17,21-orthoester intermediate, of the enol ether represented by structural formula III wherein R is hydrogen, is formed. The presence of the 17,21-orthoester has no detrimental effect on the overall reaction because it is hydrolyzed in the next chlorination step under acidic conditions. However, since the formed 17,21 orthoester reacts with added triethyl orthoacetate and because the reaction of a cortisol-like compound with acetic anhydride in pyridine is so pure and the formation of the corresponding 3-enol ethyl ether occurs completely and rapidly in step 2), it is preferable to first form the 21-ester before triethyl orthoate. reaction. Therefore, this preferred method is shown in the reaction scheme.

14 6578 4 3) After isolation of 3-enol ether III, it is halogenated to form a 6-halogen compound of structural formula I. The halogenation step is either the above-mentioned chlorination or bromination step.

4) The compound represented by the structural formula I is a β-halogen-substituted compound. Before it can be reacted with triethyl orthoacetate to efficiently form the 3-enol ether of structural formula XII, the halogen must be converted to a 6 O-halogen. This is accomplished by immersing the 6β-halogen-substituted Compound I in an inert solvent at about room temperature (20-25 ° C), adding a small portion of the acid catalyst, and maintaining the temperature for one hour or less, preferably 30 minutes or less. The reaction is carried out mainly in a glyme solvent in the presence of 1% by weight or less of a strong organic acid catalyst, such as, for example, trifluoroacetic acid or p-toluenesulfonic acid. The conversion to the 6 Qi halogen compound is complete with a reaction time of less than 1 hour, usually less than 1/2 hour. Ethanol and triethyl orthoacetate are then added to the reaction mixture and the mixture is reacted according to the main object of this invention to form the 3-enol ether of formula XII.

After isolation, intermediate XII can be converted to the desired final product by known methods.

5a) The compound of formula XII can be reacted to directly form the A '' - pregnatriene of structural formula VI '. In a one-step embodiment, a compound of formula XII may be reacted with, for example, 2,3-dichloro-4,5-dicyanobenzoquinone (DDQ) in a substantially dry, suitable solvent, such as dioxane, at room temperature to form a Δ '' pregnatriene of formula VI '. -21 ester, which in turn can be hydrolyzed under basic conditions, or transesterified to form a 21-hydroxy steroid of formula XV wherein Z is a double bond.

5b) In order to obtain higher yields, a mainly two-step process is used, in which a compound of formula XIII is first formed, the 1-position of which is dehydrated, after which a compound of formula VI 'is formed. The compound of formula XIII or VI 'can then be hydrolyzed to form a structure of formula XV wherein Z may be either a single bond or a double bond. A compound of formula XIII is formed by reacting a compound of formula XII with a suitable oxidizing agent (tetrasubstituted 1,4-benzoquinone) at low temperatures (about 0-10 ° C) in a wet solvent such as dioxane or acetone with a volume of water. -% or less. A particularly suitable oxidant is 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ). Generally, this reaction is complete in two hours or less.

5c) The 4,6-pregnadiene of the formula VI "is isolated and then the 1-position is dehydrated to form the compound of the formula VI '. The dehydration can be carried out in a manner known per se, either chemically or microbiologically. The 4,6-pregnadiene of the formula VI" is isolated before dehydration according to the next step. When the 1-position is selectively chemically dehydrated, compound VIII is reacted with a suitable oxidizing agent under substantially dry conditions in a suitable solvent such as an oxygenated hydrocarbon, for example alcohol, dioxane or acetone, at a temperature between room temperature and boiling point. A suitable oxidant is DDQ and suitable solvents include xylene, toluene, amyl alcohol, dioxane or acetone. The substance is allowed to boil in the solvent until dehydration occurs. This usually takes 1 to 20 hours when using chloranil in amyl alcohol, or about 12 to 16 hours in xylene. When using DDQ in dry acetone, the time required is only about 4 hours at boiling temperature.

However, the dehydrogenation of the A-position is preferably carried out by a method in which the 2-position is brominated and dehydrobromated between the 1- and 2-positions to form a double bond. The bromination is carried out by reacting a suitable brominating agent with Λ '-pregnadienes in a suitable solvent until the reaction is complete. Suitable brominating agents include a mixture of bromine and hydrogen bromide in the presence of acetic acid at room temperature for a reaction time of 10 minutes and a yield of the reaction product of about 85% or better.

65784 16

A particularly valuable brominating agent when performing 2-bromination is pyridinium hydrobromide perbromide or trimethylphenylammonium tribromide in tetrahydrofuran; a suitable temperature is 30 ° C or lower, preferably about 20-25 ° C.

The resulting 2-brominated product is cleaved with hydrogen bromide by reacting the 2-bromine product with a hydrogen bromide cleavage agent. Typical debromination reactions can be found in Steroid Reactions, An Outline For Organic Chemists, Carl Djerassi,

HoIden-Day (1963), ss. 213 - 218.

The following examples are provided to illustrate the process of the invention (Examples II, III, V, VI and VII are comparative examples and Examples X and XI illustrate methods for providing an & double bond).

Example I

20 g of cortisol-21-acetate was added to a mixture of 100 ml of anhydrous ethanol and 100 ml of ethylene glycol dimethyl ether (glyme). The solution was warmed to 40 ° C and 2 g of p-toluenesulfonic acid (PTSA) was added followed by 24 g of triethyl orthoacetate. The reaction mixture was stirred at 40 ° C until dissolution occurred and then stirred for a further 20 minutes at 40 ° C, cooled to room temperature and 2 ml of pyridine were added. The reaction mixture was slowly poured into a mixture of 520 ml of water and 52 ml of hexane. After 30 minutes at 0-5 ° C, the product was filtered off and washed with water, then 50 ml of hexane and dried in vacuo at 40 ° C. The yield was 90 - almost 100%.

Following the procedure of Example I, but using 2 g of trifluoroacetic acid or 2 g of sulfuric acid instead of PTSA as the acid catalyst, corresponding yields were obtained.

Example II (Comparative Example) The purpose of carrying out this example is to show the differences between the yields and products of the process according to the present invention and the known process currently used for the purpose. In this comparative example, 10 g of cortisol-21-acetate was added to a mixture of 100 ml of anhydrous ethanol, 10 ml of triethyl orthoformate and 0.300 g of 2,4-dinitrobenzenesulfonic acid. The mixture was stirred at room temperature until dissolution occurred. The reaction mixture was stirred for a further 15 minutes and 1 ml of pyridine was added. The solution was concentrated to half its volume and 10 ml of water was added. Concentration was continued until crystallization occurred. About 100 ml of water were added and the product was filtered off, washed well with water and dried to give the corresponding 3-enol ether. In this particular case, some dehydration product appeared, which did not occur at all in Example I, leaving about 10% unreacted material as well as a small amount of other undesired products compared to Example I, which left substantially less unreacted material as determined by plate chromatography (TLC). by.

Example III (Comparative Example Network) This example demonstrates that the presence of triethyl orthoacetate is necessary for carrying out the process of the invention. This example otherwise used exactly the technique and amounts of Example I, but the triethyl orthoacetate was replaced with triethyl orthoformate. Analysis of the final products by plate chromatography (TLC) showed that a small amount of starting material remained, but in addition a substantial amount of intermediates and 9 (111 about 10-15% A dehydration product).

Example IV

20 g of cortisol were added to a mixture of 100 ml of anhydrous ethanol and 100 ml of ethylene glycol dimethyl ether, as in Example I. In this example, the procedure of Example I was followed in other respects, but now 0.3 g of 2,4-di-nitrobenzenesulfonic acid and 10 g of triethylorthoacetate were used. The results showed that the reaction was essentially complete, during which about 17,21-orthoester of about 15 * 3-enol ether was formed. The presence of this product has no detrimental effect in the process according to the invention, since the product can be allowed to react further and, at the end of the reaction series, the 17,21-orthoester can be easily hydrolyzed to form the desired 11 / 5.17 O ·, 21-trihydroxysteroid.

18 6 5 7 8 4

Example V (vertical example)

Otherwise, the same procedure as in Example III was followed, but no ethylene glycol dimethyl ether was used. At the end of the reaction series, a significant amount was still left, i.e. about 10% of the original unreacted starting material. Thus, this also emphasizes the need for the presence of triethyl orthoacetate in order for the reaction to be complete.

Example VI (Comparative Example) This example demonstrates that the process of U.S. Patent 3,087,927 does not provide the desired product.

In order to further demonstrate the importance of the presence of triethyl orthoacetate and also the importance of the fact that the majority of the solvent is ethanol, 30 g of cortisol-21-acetate are suspended in a solution prepared from 300 ml of dioxane, 30.0 ml of trimethyl orthoformate and 1, 20 ml of anhydrous methanol. To the vigorously stirred suspension is added dropwise 0.60 ml of concentrated sulfuric acid. The suspension thins continuously for the first 5 minutes and complete dissolution has occurred in 6 minutes. 1.80 ml of pyridine are added, after which the faint pink color disappears immediately and the resulting solution is pale yellow in color. Until now, the process is carried out at room temperature. The cooled reaction solution is placed in a separatory funnel, the tip of which is immersed below the surface of a water-ice mixture of 300 ml in a large beaker. The reaction mixture is slowly added over 2-3 hours to a vigorously stirred ice-water mixture. The solid formed is allowed to stand in solution at 5 ° C overnight and then separated by filtration. The product is washed well with water and air dried to give 28.7 g of product. TLC analysis of the product (9) showed that the final product was A-21 acetate.

Example VII (Comparative Example) In this example, the same procedure as in Example VI was followed, but anhydrous ethanol was used instead of methanol, and triethylorthoacetate was used instead of trimethyl orthoformate. Following the procedure of Example VI, almost no reaction occurred. This shows how important it is that the majority of the solvent is ethanol and that the process of U.S. Patent 3,086,927 does not give the desired result.

19 65784

From the above examples and Table I, it can thus be seen that the process of this invention in which a steroid is reacted with triethyl orthoacetate in a solvent consisting predominantly of ethanol and a minor oxidized hydrocarbon solvent such as glyme gives results better than those obtained by known methods. .

20 65784

Table I

** i + TEQA TBOF Ethanol Glyyrai H CAT Results I Invention X - X X X Reaction complete II Previous method X X X Reaction incomplete III Earlier method X X X X Reaction incomplete 9 (11),. , nen, Δ. dehydration product *** IV Invention X XXX Reaction complete, slightly 17,21-orthoesters (not harmful) V Early way XXX Reaction incomplete * 9 (11) VI Early way Little Dick- Only Δ '' dehydrate - (US 3,087,927) - TMDF methanane X thio product lia VII Earlier way Slightly Dick- (US 3,087,927) X meazane X No reaction nolia 65784 21

Example VIII

The following series of reactions correspond to a particularly efficient process for the preparation of 6-chloro-Δ1'4'6-pregnatriene-11 / 5,170 », 21-triol-3,20-dione from cortisol.

Preparation of cortisol-21-acetate

Reaction: ch2oh CH 2 OAc C = 0 c = 0

CH3 I CH

HO. HL-oh CH3 CH2

Ac2 ° - - *

Procedural:

Place 400 ml of pyridine in a one-liter flask and add 100 g (0.276 mol) of hydrocortisone (cortisol), which begins to dissolve. Keeping the temperature below 30 ° C over 10 minutes, 163.3 g (1.59 moles) of acetic anhydride are added. The mixture is allowed to stand for one hour at room temperature until the reaction is complete. 300 ml of water are slowly added to the reaction mixture, keeping the temperature below 40 ° C. The reaction mixture is allowed to stand for 20 minutes and then transferred to a 3 liter flask. Within 20 minutes, 1500 ml of saturated aqueous sodium chloride solution are added. The mixture is cooled to 10 ° C, kept for one hour and filtered. The product is washed with water and dried at 50-60 ° C under vacuum. Yield: 110.4 g (110.4% by weight; 99.2% of theory).

Reaction with triethyl ortho-acetate to form 3-enol ether followed by chlorination at the 6/3 position

Reaction: 22 6 5 7 8 4 ch2oac ch2oac ~ C = ° C = 0

HO ^ _ JL__oh I

Hov. -0H

° "^ CH3C (OC2HS) 3 c2h50o ^ · ^^^ H * [CH OAc c = o

HaUne® "" γ ^ ΐΛ-0 "

S

o ci

Procedural; 550 ml of ethanol, 330 ml of 1,2-dimethoxyethane (glyme) and 110.4 g (0.272 mol) of cortisol-21-acetate are placed in a 2-liter flask. The mixture is heated to 40-42 ° C and a solution of 9 g of p-toluenesulfonic acid in 200 ml of 1,2-dimethoxyethane is added, followed by 116 g of triethylorthoacetate. The temperature is maintained between 38-42 ° C.

After 20 minutes, 2.5 g of p-toluenesulfonic acid are added. The mixture is left to stand for 30 minutes at 38 to 42 ° C, then cooled to 8 to 10 ° C and 12 ml of pyridine are added, followed by a solution of 2.7 g of sodium acetate in 50 ml of: in water. The pale yellow solution is poured into a mixture of 14 g of sodium acetate, 2.450 ml of water and 288 ml of hexane, then cooled to 10 ° C, kept for 20 minutes, filtered and washed with 800 ml of water containing 1 g of sodium acetate and treated with after 220 ml of hexane.

The wet cake (about 200 g) is placed in a cold mixture (10 ° C) of 13.7 g of sodium acetate in a solution of 184 ml of water and 440 ml of acetone and cooled to 0-5 ° C. While maintaining the temperature below 5 ° C, a solution of 27 g of Halane a (registered trademark} 1,3-dichloro-5,5-dimethylhydratoin) in 120 ml of acetone is added. The mixture is kept at 0-5 ° C for 45 minutes, then a solution of 9.2 g of sodium hydrogen sulphite in 132 ml of water is added and the mixture is slowly drained over 30 minutes into 2200 ml of water and cooled to 0-5 ° C. for one hour, filtered and dried at 45-50 ° C in a vacuum oven. Yield: 107.2 g (97.1% by weight; 89.5% of theory).

65784 24

Reaction with triethyl orthoacetate to give the 3-enol ether followed by the Δ 'compound Reaction: CH 2 OAc. CH 2 OAc "C = O c = O

HO _ JL - OH I

\ / \ υπ HO. - OH

[CH 3 C (OC 2 H 5) 3 c 2 H 5 O 2

Cl ^> Cl CH90Ac c = o

HO L__OH

DDQ

-> dioxane

Cl

Procedure: 104 g (0.237 moles) of 6H-chloro-1,701,21-trihydroxypregn-4-ene-3,20-dione-21-acetate (from the previous step) are placed in a 2 liter flask, 500 ml of 1.2 -dimethoxyethane and 3.03 g of p-toluenesulfonic acid and the mixture is kept at 20-25 ° C for 30 minutes. 500 ml of ethanol are added, followed by 91.4 g (0.563 mol) of triethyl orthoacetate. The reaction mixture turns dark red and is left to stand for 40 minutes at 20-25 ° C, then cooled to 15 ° C and a solution of 13 g of sodium acetate in 640 ml of water is added. The temperature is kept below 20 ° C and 220 ml of methylene chloride are added, followed slowly by 1000 ml of water, keeping the temperature below 25 ° C. The mixture is stirred for 15 minutes and the lower organic layer is separated. The upper layer is extracted with 3.75 ml portions of methylene chloride. The organic fractions are combined and washed with a solution of 1.3 g of sodium acetate in 260 ml of water. The methylene chloride extract (total about 900 ml) is separated and concentrated in vacuo to about 400 ml and a mixture of 850 ml of dioxane and 1.3 ml of pyridine is added by distillation, keeping the volume between about 400 and 450 ml. Distill the mixture until the final volume is 400 ml (in which case no methylene chloride must be present) and add 300 ml of dioxane. The mixture is cooled to 10 ° C and 65 ml of water are added, and then cooled to 0-5 ° C. A solution of 75 g of DDQ in 300 ml of dioxane is added over the course of one hour while maintaining the temperature at 0-5 ° C. The addition funnel is washed with 30 ml of dioxane and the mixture is kept at 0-5 ° C for 30 minutes. A solution of 30.4 g of sodium hydrogen sulphite in 87 ml of water is added keeping the temperature below 10 ° C. The slurry is concentrated in vacuo to 600 mL. The slurry is slowly added to 3000 ml of water with vigorous stirring, then cooled to 10 ° C and kept for 3 hours. The product mixture is filtered and washed with water. The wet solid is taken up in 1500 ml of methylene chloride, stirred for one hour, filtered and washed with 100 ml of methylene chloride. The solid is poured into 400 ml of methylene chloride, stirred for 20 minutes, filtered and washed with 100 ml of methylene chloride. The methylene chloride solutions are combined and mixed with 1000 ml of water. The organic layer is separated and the aqueous layer is extracted with 50 ml of methylene chloride. The methylene chloride extracts are concentrated to 400 ml and 1000 ml of acetone are added by distillation, keeping the volume between about 360 and 400 ml. The slurry is distilled to a final volume of 300 ml and cooled to 0-5 ° C, kept here for 30 minutes, filtered and washed with 82 ml of cold (0-5 ° C) acetone. The product is dried in vacuo at 50 ° C. Yield: 80.3 g (77.2% by weight; 77.5% of theory).

26 6 5 7 8 4 Formation of the Δ compound followed by hydrolysis

Reaction: CH 2 OAc CH 2 OAc c = o c = o

H0 '0H

+ -. . . CcHcNHBr- 5 5 3

THF 7 I

Cl cl

Li2CO ^ / LiBr

DMF

Ψ CH2OH CH2OAc c = o c = 0

H ° 0H

MeOH

K2C03

Cl

Cl 27 65784

Procedure: 50 g of RS-4232 acetate (from the previous step, containing about 10% acetone) are added to 350 ml of methylene chloride. 30 g of inert alumina are added and the mixture is stirred for one hour. The alumina is filtered off and the solution is concentrated to 50 ml. Tetrahydrofuran (400 ml) is added and distillation is continued until a boiling point of about 65 ° C is reached. The mixture is cooled to 25 ° C and a solution of 34 g of pyridine hydrobromide perbromide in 130 ml of tetrahydrofuran is added. The reaction mixture is stirred at 25 ° C and 3 ml of acetone are added. The reaction mixture is filtered and the filtrate is concentrated to 50 ml. Dimethylformamide (400 ml) is added followed by 22.5 g of lithium carbonate and 8.1 g of lithium bromide. The system is purged with nitrogen and the reaction mixture is heated at 105 ° C for 2 1/2 hours, concentrated in vacuo to 200 ml, cooled to 60 ° C and 50 ml of acetic acid are added, followed by 70 ml of water. The reaction mixture is slowly added to 1600 ml of water. After 1 hour at 25 ° C, the product is filtered off and washed with water and dried in vacuo at 60 ° C. Yield: 41.5 g (83% by weight). The product is crystallized twice from acetone; yield after purification: 78.8% by weight.

6-Chloro-1H-17β, 21-trihydroxy-pregna-1,4,6-triene-3,20-dione is formed by transesterification in dry methanol in the presence of a small amount of potassium carbonate.

Example IX

The procedure of Example VIII is followed to give 6-chloro-11,3,17,11,2-trihydroxypregna-4,6-diene-3,20-dione-21-acetate which is transesterified to the corresponding 21-hydroxy compound by reacting the compound. with dry methanol in the presence of a small amount of potassium carbonate.

Example X (Comparative Example) This example shows a method for forming Compound A by microbiological means (by growing cells in the presence of a hydrogen-binding agent).

28 6 5 7 8 4 A. Fermentation

A culture of Arthobacter simplex NRRLB-8055 is cultured for 6 days at 28 ° C in an agar medium having the following composition: (A):

Nutrient agar (Difco) 20 g

Glucose 10 g

Yeast extract (Difco) 10 g

Distilled water 1 liter

The loop surface growth is used to implant the medium in two 300 ml Nephlo culture flasks (Bellco Inc.), each containing 50 ml of the following sterile nutrient: (B):

Corn extract liquid 5 g

Yeast extract (Difco) 1 g

Serellose (glucose monohydrate) 0.5 g Distilled water 1 liter pH 7

The flasks are germinated in a thermostat at 28 ° C on a rotary shaker at 280 rpm and an impact length of 25 mm. Germination is complete after 24 hours or when the turbidity of the culture is 165 to 180 Klett units as measured by a Klett-Summerson photoelectric color retractor equipped with a No. 66 filter and the zero point adjusted using sterile medium. The contents of each flask are then used in their entirety to germinate a batch of 900 ml of medium in a 2-liter glass fermentation flask using freshly sterilized medium (B). The fermentation flask is continued to germinate at 28 ° C with ventilation readings of 1/2 vol. weather / 1 spacious. medium / minute and mixing speed 300 rpm. / Min. After 24 hours, 500 mg of 6-chloro-11β, 17β, 21-trihydroxy-pregna-4,6-diene-3,20-dione (prepared as described in Examples VIII and IX) are added to the fermentation broth as an ethanol solution. (25 mg / 0.4 ml ethanol). At the same time, 26.4 mg of manedione sodium hydrogen sulfite as a filtered, sterilized aqueous solution (26.4 mg / 10 ml) are added to the fermentation broth. Germination is continued as above. The reaction is complete after 3-5 hours.

29 0 5 7 8 4 B. Isolation and characterization The fermentation broth is extracted 3 times with 500 ml portions of chloroform. The combined chloroform extracts are dried over anhydrous sodium sulfate and concentrated to dryness in vacuo. The resulting semicrystalline residue is purified by chromatography on silica gel. The product is eluted with mixtures of chloroform and acetone. The fractions containing the desired product were combined and evaporated to dryness to give 475 mg of 14 6 (yield 95% of theory) of 6-chloro-Δ '' -pregnatriene-11 / i, 17 ° C, 21-triol-3,20-dione, which then crystallized from isopropyl acetate.

In a similar manner, replacement of menadione sodium hydrogen sulfite with menadione and tetramethyl-p-benzoquinone by 6-chloro-Δ4'β-pregadiene-1β, 17β, 21-triol-3,20-dione is converted to 6-chloro-®- pregnatriene-11 / 3.17 to O, 21-triol-3,20-dione.

Example XI (comparative example)

Arthobacter simplex inocula are prepared in the same manner as in Example X.

5 ml of a 24-hour seed culture is then used for germination in four 250 ml Erlenmeyer flasks, each containing 50 ml of medium (B) (Example I). The flasks are incubated at 28 ° C on a rotary shaker at 280 rpm and an impact length of 25 mm. After 24 hours, 25 mg of 6-chloro-Δ4'6-pregnadiene-11 / β, 17OL, 21-triol-3,20-dione (prepared as in Examples VIII and IX) dissolved in 0.4 ml of ethanol are added to each flask. 0.887 mg of 2-isopropyl-5-methyl-p-benzoquinone dissolved in 0.2 ml of ethanol are added simultaneously to one flask. 0.83 mg of 2-hydroxy-1,4-naphthoquinone is added to the second flask and 1.2 mg of 2,6-dichloroindophenol sodium salt dissolved in 0.5 ml of water is added to the third flask. No hydrogen scavenger is added to the fourth flask used for comparison. Analysis of the solvent-extracted samples taken after 7 and 24 hours of contact time by plate chromatography showed that 6-chloro-Δ * '4' ** - pregnatriene-11 / 1,17 O * ·, 21-triol-3, The amount and percent formation of 20-dione product had increased compared to the untreated control.

Claims (3)

65784 30 A process for the preparation of 11β-hydroxy-Δ 2 '6 and Δ 1' 4'6-pregnadi- and trien-3-ones of the formula ch 2r c = 0 VI X wherein R is H, OH, 1-6 an alkyl ether or alkyl ester group containing 1 carbon atom, R is H, OH or a 2 alkyl ester group having 1 to 6 carbon atoms, R is H, d-CH- or / S-CH 2, X is H, F, Cl or 1 2 Br, or R and R together form a group -O 2 R 4 -OC ^ 4 5 in which R and R independently of one another denote hydrogen atoms or a hydrocarbon group having 1 to 4 carbon atoms, characterized in that a 3-enol ether is formed by reacting the corresponding 3-keto-4 A- steroid to react with triethyl orthoacetate in the presence of a catalytically effective amount of a strong acid in a solvent consisting essentially of more than about 40% by weight ethanol and less than about 60% by weight ethanol miscible solvent, preferably dimethylated ethylene glycol such as ethylene glycol 6 , followed by a Δ- and / or Δ> 'bond, followed by ha the potential protecting group is hydrolyzed in a manner known per se. 31 65784 Process for the preparation of 6-chloro-pregna-1. f'A-triene-11 / S, 17QL ·, 21-trihydroxy-3,20-dione according to Claim 1, characterized in that the corresponding 4 3- keto-A. steroid. Process for the preparation of 6-chloro-pregna-Zk1, 4'4-triene-11β, 17β, 21-trihydroxy-3,20-dione according to Claim 1, characterized in that 6β-chloro-pregna A4-11 / 17.17, 21-trihydroxy-3,20-dione-21-acetate. 32 65784