GB2080308A - 11-amino-androstane-17-carboxylates - Google Patents

Description

1

GB 2 080 308 A 1

SPECIFICATION 11 a-amino-androstanes

This invention relates to aminosteroids having antidysrhythmic acitivity, and in particular to certain compounds in the androstane series having a substituted amino group at the 11 cr-position.

5 The aim of antidysrhythmic therapy is to return hazardous abnormal heart rhythms towards 5

normal, or to reduce the likelihood of hazardous rhythms developing in patients at risk as a result of hypertension, atheromas, diabetes or heart conditions such as myocardial disease, ischaemia or infarction.

It is recognised that dysrhythmias in patients with heart attack and other conditions are treatable .10 and preventable. There are several drugs available for the treatment of ventricular dysrhythmias but 10 their application is limited by their lack of efficacy or by their toxicity which gives rise to various side effects.

Thus there is a demand for drugs suitable for use in the treatment of patients with dysrhythmias, and therefore in danger of sudden cardiac death. Furthermore, there is a demand for such drugs for 15 administration, for example for long term prophylaxis, to patients at risk of developing dysrhythmias, in 15 which case, activity on oral administration is desirable.

In Belgian Patent Specification 853227 there is described a group of 11 a-tertiary amino-3r*-hydroxy steroids having anaesthetic activity. In addition to the 11 a-tertiary amino and 3or-hydroxy groups, the possibility of the compounds possessing various substituents in other positions including 20 the 17/3-position is allowed for, one possible 1 7/3-substituent being a C,_s alkoxycarbonyl group. 20

Corresponding 11 a-primary and secondary amino steroids are also described as intermediates for the preparation of the tertiary amino compounds. There is no specific disclosure in Belgian Patent 8*53227 of any 11 ^-primary or secondary amino-17/3-alkoxycarbonyl compounds, and no anaesthetic activity is ascribed to any such compounds specifically. Furthermore, no antidysrhythmic activity has been 25 ascribed to any of the compounds in the above Belgian Patent Specification, or indeed to any 25

compounds of comparable structure.

We have now discovered that a group of 11 a-secondary amino-3cr-hydroxy steroids having a 17/5-carboxylic ester group have surprisingly high anti-dysrhythmic activity while lacking general anaesthetic activity. The antidysrhythmic activity of the compounds is significantly greater than that 30 possessed by the analogous compounds specifically disclosed in Belgian Patent Specification 853227, 30 having other 17/3-groups. The compounds thus have potential for use as antidysrhythmic drugs.

Accordingly the invention provides compounds of the formula wherein R1 is a C,^ alkyl group or a C3_7 cycloalkyl group;

.35 Rz is a hydrogen atom, a C.,_6 alkoxy group or a C2_5 alkanoyloxy group; and 35

R3 is a C,_8 alkyl group or a C3_7 cycloalkyl group;

(provided that when the compounds contain a 5/3-hydrogen atom, R2 is a hydrogen atom) and the D-homo analogues thereof having the group —C02R1 (wherein R3 is defined above) at the 17a\b-position, and acid addition salts thereof.

40 Where R1 or R3 is a cycloalkyl group it may be for example a cyclopropyl, cyclobutyl, cyclopentyl, 40

cyclohexyl or cycloheptyl group.

Where either of the groups R1 and R3 is an alkyl group, such a group may be straight or branched-chained.

Where R' is an alkyl group, it preferably has 3—7 carbon atoms, and may for example be a propyl, 45 butyl, pentyl, isopentyl, hexyl, isohexyl or neohexyl group. Where R2 ;is an alkoxy group it may be for 45 example a methoxy, ethoxy, propoxy, butoxy, pentyloxy or hexyloxy group; an example of an alkanoyloxy group is the acetoxy group. Where R3 is an alkyl group it may for example be a methyl, ethyl, propyl, isopropyl, butyl or isopentyl group.

The total number of carbon atoms in the groups R1, R2 and R3 together is preferably from 3 to 10 50. carbon atoms. 50

R3 is preferably a C,^ alkyl group, and where compounds having good activity on oral administration are desired, R3 is preferably a methyl or ethyl group.

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GB 2 080 308 A 2

Ring D conveniently has five members.

The compounds preferably have a 5o--hydrogen atom.

Preferred compounds are 5a-androstanes having five members in ring D in which: R1 is an isopentyl, hexyl, isohexyl, neohexyl, cyclopentyl or cyclohexyl group; R2 is a hydrogen atom or a 5 methoxy, ethoxy or propoxy group, especially a methoxy or ethoxy group; and R3 is a methyl or ethyl 5

group, especially a methyl group.

The compounds of formula (I) may form acid addition salts; physiologically acceptable salts are preferred. Examples of such salts are hydrochlorides, hydrobromides, phosphates, sulphates, p-toluenesulphonates, methanesulphonates, citrates, tartrates, acetates, ascorbates, lactates, maleates, 10 succinates, tricarballylates, glutarates and glutaconates. The hydrochlorides are preferred acid addition 10 salts..

Individual compounds which are preferred on the basis of their high antidysrhythmic activity include:

I. methyl 2/5-ethoxy-3o--hydroxy-11 a-(3-methylbutylamino)-5ar-androstane-17/3-carboxylate,

15 2. methyl 2/3-methoxy-3cr-hydroxy-11a-(3-methylbutylamino)-5a;-androstane-17/3-carboxylate, 15

3. methyl 11 a--cyclohexylamino-2/J-ethoxy-3tt-hydroxy-5a:-androstane-17/5-carboxylate,

4. methyl 11r*-(3,3-dimethylbutylamino)-2/3-ethoxy-3a;-hydroxy-5ar~androstane-17/5-carboxylate,

5. methyl 11 «-cyclohexylamino-3a-hydroxy-2/5-methoxy-5a-androstane-17/3-carboxylate,

6. methyl 3<*-hydroxy-11 ar-(3-methylbutylamino)-5a-androstane-17/3-carboxylate,

20 7. methyl 11ar-cyclohexylamino-3a;-hydroxy-5a:-androstane-17/3-carboxylate, 20

8. methyl 11 <?-cyclopentylamino-3ar-hydroxy-5a;-androstane-17/3-carboxylate,

9. methyl 3rr-hydroxy-11 flr-(3-methylbutylamino)-2/3-propoxy-5a-androstane-17/3-carboxylate,

10. methyl 2/3-ethoxy-11 or-hexylamino-3o:-hydroxy-5ar-androstane-17/3-carboxylate,

II. methyl 11 (•r-cyclopentylamino-3<*-hydroxy-2/5-methoxy-5«-androstane-17/3-carboxylate,

25 12. ethyl 2/3-ethoxy-3r*-hydroxy-11cH3-methylbutylamino)-5ar-androstane-17/3-carboxylate, 25

13. methyl 11 a-cycloheptylamino-3o:-hYdroxy-2/3-methoxy-5ar-androstane-17/3-carboxylate and

14. methyl 11 <r-cyclobutylamino-3ar-hydroxy-2/3-methoxy-5a-androstane-17/3-carboxylate and their physiologically acceptable acid addition salts, e.g. their hydrochlorides.

A highly preferred member of this group is compound 1 and its physiologically acceptable acid 30 addition salts such as the hydrochloride salt. Investigations both in vitro and in experimental animals 30 have shown that this compound possesses a highly desirable combination of pharmacological properties. In particular, against aconitine-induced dysrhythmias in anaesthetised rats the compound exhibited high levels of activity following both oral and intravenous administration. The oral and intravenous therapeutic indices were high and a single oral dose of the compound gave a prolonged 35 duration of action. The compound was highly effective in reducing the mortality and the incidence and 35 duration of ventricular bigeminy, tachycardia and fibrillation in coronary artery-ligated anaesthetised rats. The compound was effective, when administered intravenously or orally, against post-infarction dysrhythmias in the conscious dog.

Other compounds possessing similar properties to compound 1 are compounds 2, 5 and 7. 40 The compounds may be used in the treatment of patients with disturbances of cardiac rhythm, 40 whether arising spontaneously, or as a result of treatment with other drugs, e.g. cardiac glycosides, or as a consequence of myocardial ischaemia or infarction. Alternatively, they may be used for the prophylactic treatment of patients at risk of cardiac rhythm disturbances or sudden coronary death. The invention accordingly further provides compounds of formula (I) and their physiologically 45 acceptable acid addition salts for use in the therapy or prophylaxis of cardiac dysrhythmias in a human 45 or animal subject. The invention also provides compounds of formula (I) and their physiologically acceptable acid addition salts in association with instructions for their use in the therapy or prophylaxis of cardiac dysrhythmias in a human or animal subject.

As a further aspect of the invention there are provided compounds of the formula

(wherein Rz is as hereinbefore defined (provided that when the compounds contain a 5/3-hydrogen atom, R2 is a hydrogen atom), R4 is a hydrogen atom or a group R1 as hereinbefore defined and R5 is a hydrogen atom or a group R3 as hereinbefore defined, provided that at least one of R4 and R5 is a

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GB 2 080 308 A 3

• hydrogen atom) and the D-homo analogues thereof having the group —C02R5 at the 1 7a'/3-position,

and salts and zwitterionic forms thereof.

The compounds of formula (II) may form acid addition salts. The compounds of formula (II) in which the group —C02Rs represents a carboxyl group may also form salts with bases or exist as 5 zwitterions. 5

Examples of acid addition salts are those given above in connection with the compounds of formula (I). The salts with bases may be salts with inorganic bases such as alkali metal salts, e.g.

sodium, potassium and lithium salts; alkaline earth metal salts, e.g. calcium and magnesium salts; and ammonium salts, or salts with organic bases for example amine salts.

10 Compounds of formula (II) are useful as intermediates in the preparation of compounds of formula 10

(I) using the methods described hereinafter.

The compounds of the invention may be prepared by a number of different methods, using generally known techniques. Suitable methods are described below:

1. A substituent on the 11 a-amino function may be introduced by reacting the corresponding 15 11 a-amino compound, i.e. a compound of formula (II) in which R4 is hydrogen, with a compound of the 15 formula R1X wherein X is a readily displaceable atom or group such as a halide (e.g. iodide), a hydrocarbylsulphonyloxy group (e.g. toluene-p-sulphonyloxy), a hydrocarbyloxysulphonyloxy group (e.g. methoxysulphonyloxy) or a dialkoxyphosphonyloxy group (e.g. dimethoxyphosphonyloxy). When carried out on compounds of formula (II) in which R5 is also hydrogen, such a reaction may result in 20 esterification to form a compound of formula (I) in which R1 = R3. The group R3 may, if not desired in the 20 final product, subsequently be replaced by transesterification, for example as set out under 8. below. The introduction of the substituent on the 11 ar-amino function is preferably carried out in the presence of a base (e.g. potassium carbonate or silver oxide) in solution at any suitable temperature from ambient to reflux (e.g. +20 to +100°C). The reaction is conveniently effected in a suitable reaction solvent.

25 Suitable solvents include ethers (e.g. dioxan), substituted amides (e.g. N,N-dimethylformamide or N,N- 25 - 1 dimethylacetamide), sulphoxides (e.g. dimethylsulphoxide), alkanols (e.g. ethanol or methanol) or acetonitrile.

When X is a chlorine or bromine atom, the reaction may be facilitated by addition of an iodide such as sodium iodide.

30 Compounds of formula (II) wherein R4 is hydrogen may be prepared by reduction of the 30

corresponding 11-oxime. Such a reduction may be effected with an alkali or alkaline earth metal in an alcohol and/or an amine and/or ammonia, e.g. sodium in /7-propanol, if desired in the presence of a suitable solvent, e.g. tetrahydrofuran, at any suitable temperature up to and preferably at reflux.

The 11-oximes may themselves be prepared from the corresponding 11-oxo compounds. The 11-35 oxo compound may for example be reacted with hydroxylamine under strongly alkaline conditions in 35 aqueous alcohol (e.g. ethanol), preferably at reflux. The reaction may also be carried out under acidic conditions (ca. pH 4), e.g. in buffered pyridine.

The severe conditions used in the reduction of the 11-oxime make it necessary or desirable that certain substituents for example the 17/3-alkoxycarbonyl substituent and a 2/3-alkanoyloxy substituent 40 where required should be introduced after the formation of the 11 a-amino group. 40

2. Opening of a corresponding 2a,3a-epoxide.

This reaction may be used to prepare 2/5-substituted 5a-compounds. The general method of preparing 2/5-compounds by this route is described in our British Patent Specification 1376892. Thus in general the reaction comprises treating the corresponding 2ar,3or-epoxide with a compound HR2 under 45 acidic conditions (if necessary in the presence of an added acid catalyst, e.g. sulphuric acid, perchloric 45 acid or boron trifluoride etherate) or a compound which produces the anion (R2)~ (where R2 is as defined above, other than hydrogen), and then (when the initial product possess a deprotonated 3or-hydroxy group) treating the product with a source of protons (e.g. aqueous ammonium chloride) to form the 3a-hydroxy group. Examples of HR2 reagents are alcohols and carboxylic acids. Examples of reagents which 50 produce (R2)~ anions are alkali metal or ammonium salts of HR2 acids and alkali metal alkoxides. The 50 reaction is preferably carried out under anhydrous conditions at any suitable temperature up to reflux.

The reaction may be carried out in a suitable solvent medium (e.g. a hydrocarbon, halogenated hydrocarbon or ether) or, when the reagent is a compound HR2, an excess of the reagent may be used as the reaction solvent.

55 The starting materials required for this reaction may for example be prepared by first introducing 55

the desired 11 rv-amino group (e.g. by the method of reaction 1 above) using a A2-starting material, then forming a salt (e.g. with toluene-p-sulphonic acid) and then epoxidising the A2-compound with a peracid, finally regenerating the free base. A2-Compounds may be prepared by formation of the 3-methane-sulphonate and subsequent elimination of methanesulphonic acid.

60 This reaction may also be used to make the intermediates of formula (II), but when the epoxidation 60 is effected in the presence of a primary or secondary 11 rf-amino group the amino group may also be protected for example as a trichloroethoxycarbonyl derivative. The trichloroethoxycarbonyl group can be removed subsequently by hydrolysis with alkali or preferably by reduction with zinc and acetic acid.

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GB 2 080 308 A 4

3. A corresponding 11a-amino compound, i.e. a compound of formula (II) in which R4 is hydrogen can be reductively "alkylated" with a monocarbonyl compound serving to introduce the group R1, in the presence of a reducing agent, the term "alkylated" being used to refer to the introduction of a cycloalkyl group as well as an alkyl group. The reducing agents which may be used are those generally known for 5 the reduction of imines, examples being formic acid (e.g. at any suitable temperature up to 5

100—120°C, for example from room temperature up to 100°, and using the carbonyl compound as the reaction solvent, in the presence or absence of water), an alkali metal borohydride or cyanoborohydride (e.g. sodium borohydride or cyanoborohydride, using an alcohol such as ethanol as solvent, suitably at room temperature), iron pentacarbonyl or an alkali metal hydrogen iron carbonylate (e.g. Fe(C0)s or 10 MHFe(C0)4 where M is sodium or potassium, at any suitable temperature up to reflux using an ether 10 such as tetrahydrofuran or an alcohol or aqueous alcohol as solvent), hydrogen in the presence of a metal catalyst (using an alcohol, e.g. ethanol, an ether, e.g. dioxan or an ester, e.g. ethyl acetate, as reaction solvent, conveniently at room temperature), or aluminium amalgam in the presence of water (conveniently at room temperature, and in the presence of an ether solvent such as tetrahydrofuran). 15 The metal catalyst may, for example, be a noble metal catalyst such as platinum, platinum oxide, 15

palladium or rhodium. The catalyst may be supported, e.g. on charcoal or kieselguhr. A homogeneous catalyst such as tristriphenylphosphine rhodium chloride may also be used. If desired the intermediate imino compound may be isolated.

Thus, for example, the use of formaldehyde, acetaldehyde, 3-methylbutanal or cyclohexanone can 20 provide the 11 a-N-methyl, N-ethyl, N-iso-pentyl or N-cyclohexyl amines respectively. It will be 20

appreciated that the conditions should be chosen to give predominantly the desired N-monosubstituted compound, and minimise production of the corresponding N,N-disubstituted compound. Reductive alkylation of the compounds of formula (II) in which R4 and R5 are both hydrogen atoms is preferably effected under basic conditions.

25 4. Reduction of a corresponding 3-oxo compound. 25

2/5-Unsubstituted steroids of the invention may be prepared from appropriate 3-oxo compounds by stereospecific reduction. 5a-compounds may be prepared by the method of Browne and Kirk (J.

Chem. Soc. C, 1969,1653) or by the method of our British Patent Specification 1409239. The latter method preferably uses a pre-formed iridium catalyst reduction system. For example, a reduction 30 system may be prepared from an iridium acid or salt (e.g. chloroiridic acid), a trivalent phosphorus 30

compound such as a phosphorous acid ester (e.g. trimethyl phosphite), water and an organic reaction medium (e.g. an alcohol such as isopropanol). The reduction system is then neutralised (e.g. to a pH of 6 to 8.5) with an organic base such as a secondary or tertiary amine (e.g. triethylamine) and reacted with the steroid. When the catalyst system is preformed by heating at reflux, e.g. for 16 to 72 hours, the 35 reduction can be accomplished for example in 2—3 hours at reflux; longer times may be necessary at 35 room temperature.

5/3-steroids may be prepared by hydride reduction of the corresponding 3-oxo compound for example with sodium borohydride using an alcohol (e.g. ethanol or pyridine as solvent.

5. Conversion of a N,N-disubstituted 11a-amine into a N-mono-substituted compound.

40 Compounds of formula (I) can be prepared from corresponding 11 ar-tertiary amino compounds by 40 replacement of one of the groups by a hydrogen atom, e.g. by dealkylation using for example sodium nitrite followed by catalytic hydrogenolysis.

Thus, in particular, the compounds may be prepared by deprotection of a corresponding 11 cx-(protected amino) compound having a substituent R1 in addition to the protecting group, which may be, 45 for example an acyl group such as a trichloroethoxycarbonyl, trifluoroacetyl or formyl group or a silyl 45 group e.g. a trimethylsilyl group. An acyl group may be removed by hydrolysis e.g. with acid or alkali. The trichloroethoxycarbonyl group may also be removed by reduction with, for example, zinc and acetic acid. Alternatively an aryimethyl protecting group such as a benzyl group may be removed by catalytic hydrogenation to produce the unprotected 11 ar-amino compound. A silyl group may be removed by e.g. 50 solvolysis, with water (optionally containing acid or base) or an alcohol, or by treatment with an ionic 50 fluoride such as tetrabutylammonium fluoride.

This method may also be used to prepare compounds of formula (II) in which R4 is hydrogen, by deprotection of a corresponding 11 cHprotected amino) compound to yield a free 11 a-amino group.

6. Esterification of a corresponding 17/3-carboxylic acid.

55 Compounds of formula (I) may be prepared by reacting the corresponding compound of formula 55

(II) in which Rs is hydrogen or a reactive derivative thereof (e.g. an acid halide or anhydride or a salt)

wjth the appropriate alcohol or alkyl or cycloalkyl halide. This reaction is preferably carried out at temperatures of —20°C to +110°C, as is described for example in our British Patent Specification

1380246.

60 Where an alcohol is used in the esterification reaction, a coupling agent may be employed, for 60 example a carbodiimide such as dicyclohexylcarbodiimide, preferably in the presence of a catalyst such as 4-dimethylaminopyridine. • ' .

5

GB 2 080 308 A 5

Alternatively, esterification may be effected using a diazoalkane such as diazomethane.

Compounds of formula (II) having R5 = hydrogen can conveniently be formed by oxidising the corresponding 17/3-acetyI compound, i.e. a pregnan-20-one, using for example NaOBr in an aqueous inert solvent medium (e.g. aqueous dioxan).

5 Compounds of formula (II) wherein R5 is a hydrogen atom may also be prepared from their 5

corresponding esters having 17/3-ester groups other than the group R3 as defined above, for example by hydrolysis under acidic or basic conditions. Examples of suitable acids for such hydrolyses include mineral acids such as hydrochloric acid; examples of suitable bases include alkali metal hydroxides and carbonates, such as sodium or potassium hydroxides or carbonates.

10 When using certain of the above reagents, for example alkyl halides, it may be necessary to 10

protect the 11 <r-amino group, for example as a trichloroethoxycarbonyl derivative.

7. Reduction of a corresponding A16-compound.

The reduction may be effected by hydrogenation in the presence of a catalyst (e.g. a palladium catalyst) in a suitable solvent (e.g. an alcohol, ether or ester). The reaction may be effected conveniently 15 at or about room temperature and atmospheric pressure in the presence of a tertiary base, e.g.

triethylamine, and/or an acid, e.g. acetic acid.

The starting materials may be prepared by reaction of the corresponding 17-oxo compound with aqueous hydrogen cyanide to produce the 17-cyanohydrin which may be dehydrated to produce the A,6-17/3-cyano compound. This yields on hydrolysis the A'M 7/3-carboxylic acid and on alkylation, the 20 corresponding A16-17/3-ester.

8. Compounds of formula (I) may also be prepared by transesterification i.e. by reaction of a corresponding compound having a 17/3-ester group other than the desired group R3 with an alcohol of formula R30H in the presence of an acid or base catalyst at any temperature from room temperature to reflux, conveniently from 50° to 100°C, so as to produce a compound of formula (I) having a different

25 1 7/5-ester group from the starting material; normally an excess of alcohol is used. Examples of suitable 25 acid catalysts include mineral acids e.g. sulphuric and hydrochloric, and examples of suitable base catalysts include alkali metal hydroxides and carbonates, e.g. sodium or potassium hydroxides or carbonates.

9. Inversion of a corresponding 3/3-hydroxy compound.

30 The compounds of formula (I) may be prepared from corresponding 3/3-hydroxy compounds by 30

introducing a readily displaceable 3/3-group such as a hydrocarbylsulphonyloxy (e.g. a p-toluene-sulphonyloxy or mesyloxy) group, the 3/3-group being displaced by hydrolysis (e.g. in acid conditions) to give the desired 3a-hydroxy group.

Alternatively, the 3/3-alcohol may be treated with diethyl azodicarboxylate in the presence of an 35 acid such as formic or benzoic acid and a phosphine such as triphenyl phosphine and the resulting 3rr- 35 protected hydroxy compound may be deprotected as described in 10. below.

10. Deprotection of a corresponding compound having a protected 3a-hydroxy group.

Compounds corresponding to compounds of formula (I) but containing protected (e.g. esterified or etherified) 3a-hydroxy groups may be formed where a 3<x-hydroxy group is deliberately protected or 40 where esterification or etherification of a 3<*-hydroxy group takes place under the same conditions as a reaction elsewhere in the molecule.

An ester (e.g. alkanoyloxy) group may be hydrolysed to give the desired 3o--hydroxy compound under mild acidic or basic conditions. Weakly basic conditions are generally most convenient (using for example an alkali metal bicarbonate in aqueous methanol at any suitable temperature up to reflux). 45 Dilute mineral acids (e.g. perchloric acid in aqueous methanol) may also be used.

An ether (e.g. tetrahydropyranyl ether) protecting group may be removed by treatment with an aqueous acid and a nitro-oxy protecting group by reduction, for example using zinc and acetic acid.

12. Acid addition salts may be prepared by reaction of the free base with a suitable acid.

The methods indicated above for preparing the compounds of the invention can be used as the 50 |ast main step in a preparative sequence. The same general methods can be used for the introduction of 50

the desired groups at an intermediate stage in the stepwise formation of the required compound, and it will be appreciated that these general methods can be combined in many different ways in such multistage processes, as will be apparent from the Examples below. The sequence of the reactions in multistage processes should of course be chosen so that the reaction conditions used do not affect groups in' 55 the molecule which are desired in the final product. 55

The D-homo analogues of the compounds of the invention having a group —C02R3 at the Proposition may be prepared by essentially similar methods, using appropriate starting materials of the required structure.

Unless otherwise stated, the methods given above for the preparation of compounds of formula (I) 60 are also applicable for the preparation of the compounds of formula (II). Base salts of the compounds of 60

15

20

40

45

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GB 2 080 308 A 6

formula (II) may be prepared by the reaction of the free acid with a suitable base. For example, alkali metal salts may be prepared by reaction with an alkali metal hydroxide, carbonate, bicarbonate or 2-ethylhexanoate.

The compounds of formula (I) and their physiologically acceptable acid addition salts may be 5 formulated for administration in any convenient way, and the invention therefore includes within its 5

scope pharmaceutical compositions comprising at least one compound of formula (I) or a physiologically acceptable salt thereof adapted for use in human or veterinary medicine. Such compositions may be presented for use in conventional manner in admixture with one or more pharmaceutical carriers or excipients.

10 The compounds of formula (I) and their physiologically acceptable acid addition salts may for 10

example be presented in a form suitable for absorption by the gastro-intestinal tract. Tablets and capsules for oral administration may be in unit dose presentation form, and may contain conventional excipients such as binding agents, for example syrup, acacia, gelatin, sorbitol, tragacanth, mucilage of starch or polyvinylpyrollidone; fillers, for example lactose, sugar, maize-starch, calcium phosphate or 15 sorbitol; lubricants, for example magnesium stearate, talc, polyethylene glycol or silica; disintegrants, for 15 example potato starch or sodium starch glycollate; or acceptable wetting agents such as sodium lauryl sulphate. The tablets may be coated according to methods well known in the art. Oral liquid preparations may be in the form of, for example, aqueous or oily suspensions, solutions, emulsions,

syrups or elixirs, or may be presented as a dry product for constitution with water or other suitable 20 vehicle before use. Such liquid preparations may contain conventional additives such as suspending 20 agents, for example sorbitol syrup, methyl cellulose, glucose/sugar syrup, gelatin, hydroxyethyl-cellulose, carboxymethyl cellulose, aluminium stearate gel or hydrogenated edible fats; emulsifying agents, for example lecithin, sorbitan mono-oleate or acacia; non-aqueous vehicles (which may include edible oils), for example almond oil, fractionated coconut oil, oily esters, propylene glycol or ethyl 25 alcohol; and preservatives, for example methyl or propyl p-hydroxybenzoates or sorbic acid. The 25

compounds or their salts may also be formulated as suppositories, e.g. containing conventional suppository bases such as cocoa butter or other glycerides.

The compounds of formula (I) and their physiologically acceptable acid addition salts may also be formulated for injection and may be presented in unit dose form in ampoules, or in multi-dose 30 containers with an added preservative. The compositions may take such forms as suspensions, 30

solutions, or emulsions in oily or aqueous vehicles, and may contain formulatory agents such as suspending, stabilising and/or dispersing agents. Alternatively the active ingredient may be in powder form for constitution with a suitable vehicle, e.g. sterile, pyrogen-free water, before use.

When the compositions comprise dosage units, each unit will preferably contain at least 5 mg, 35 more preferably at least 10 mg of the active ingredient, advantageously 25—500 mg. The daily dosage 35 as employed for adult human treatment will preferably range from 25—2500 mg preferably 50—1000 mg depending on the route and frequency of administration. The compounds may be given in divided doses, for example 1 —4 times per day.

The compounds of formula (I) and their physiologically acceptable acid addition salts may be 40 administered in combination with other therapeutic agents. 40

The following Examples illustrate the invention.

Melting points were determined in.capillaries and are corrected. Optical rotations were determined at room temperature on 1 % solutions in chloroform.

Preparative t.l.c. and column chromatography were carried out on silica.

45 Petrol refers to petroleum ether b.p. 60—80°C. 45

Solutions were dried using anhydrous sodium sulphate.

IR spectra were determined in bromoform and refer to the carbonyl stretching frequency of the 17/j-parboxylic acid ester group.

Chloroiridic acid reagent was prepared by refluxing a mixture of chloroiridic acid (50 mg), 50 isopropanol (94 mg), water (6 ml) and trimethylphosphite for 24 hours and adjusting to pH 7 by the 50 addition of triethylamine immediately prior to use.

Jones reagent was prepared from chromium trioxide (26.8 g) and concentrated sulphuric acid (23,0 ml) diluted to 100 ml with water.

The following abbreviations are used in the Tables:

55 A = acetonitrile, Ch = chloroform, M = methanol, 55

I = isopropanol. Am = 0.88 ammonia, E = ethanol,

D = diethylether, Ea = ethyl acetate and Pe = petrol.

INTERMEDIATE 1

II (f-Amino-5cr-pregn-2-en-20-one

60 A solution of 20,20-ethylenedioxy-5rr-pregn-2-en-11-one 11-oxime (9.36 g) in propan-1-ol (215 60

ml) was heated at reflux and sodium (8 g) was added over 2 hours. When all the sodium was consumed the propan-1-ol was removed by distillation. The residue was extracted with ether (x31 and these extracts were extracted with 2M-HCI solution (x3). The extracts were washedL#MS||lt[j ajari Firm 1 nht to

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GB 2 080 308 A 7

pH 9 with 0.88 NH3 solution. The mixture was extracted with ether (x2) and the extracts were washed with water, dried and evaporated to leave a solid (8.77 g) which was crystallised from ethyl acetate/petrol to give the title compound (6.15 g) in two crops. A portion was recrystallised from ethyl acetate/petrol, m.p. 127—129°C, [a]D +121°.

5 INTERMEDIATE 2 5

11 a-(2,2,2-Trichloroethoxycarbonylamino)-5ar-pregn-2-en-20-one

A solution of Intermediate 1 (0.331 g) in pyridine (3 ml) was treated with 2,2,2-trichloroethyl chloroformate (0.3 ml) and the mixture was stirred at room temperature. After 0.5 hour, the reaction mixture was diluted with water (30 ml) and extracted with ether (x3). The combined ethereal extracts 10 were washed with water (x3), dried and evaporated to give an oil. Purification by preparative t.l.c. in 10 ethyl acetate:petrol 1:3 gave the title compound as a foam (0.397 g), [ar]D +56°.

INTERMEDIATES

2/3-Ethoxy-11a-(2,2,2-trichloroethoxycarbonylamino)-3a-(2,2,2-trichloroethoxycarbonyloxy)-5a:-pregnan-20-one

15 2,2,2-Trichloroethyl chloroformate (1 ml) was added to a stirred solution of 11 a-amino-2/3- 15-

ethoxy-3f*-hydroxy-5a:-pregnan-20-one (2 g) in pyridine (20 ml). After 16 hours complete reaction was not obtained. A further quantity of 2,2,2-trichloroethyl chloroformate (1 ml) was added and after 30 minutes the mixture was diluted with water (30 ml). The mixture.was extracted with ether (x2) and the extracts were washed with 2M-HCI (x4) and water (x2) and dried. Evaporation of the solution left a 20 yellow froth which was purified by column chromatography on silica eluted with ethyl acetate:petrol 20 (1:3) to give a solid (2.5 g). A portion was crystallised from ether/petrol to give the title compound m.p. 147—149°C, [a]D +48°.

INTERMEDIATE 4

11a-(2,2,2-Trichloroethoxycarbonylamino)-5a-androst-2-ene-17/3-carboxylic acid 25 Bromine (0.61 ml) was added to a solution of sodium hydroxide (1.44 g) in water (10.8 ml)

keeping the temperature at —10°C. Dioxan (5.4 ml) was added and the resultant mixture was added to a stirred solution of Intermediate 2 (1.47 g) in dioxan (25.5 ml) and water (8.1 ml) at 10°C. After 4 hours at 10°C sodium sulphite (0.45 g) was added and the mixture was stirred for 0.25 hour. The reaction mixture was filtered and the filtrate was brought to pH 2 with concentrated HCI solution. The 30 suspension was extracted with chloroform (x3). The extract was washed, with water, dried and evaporated to leave a froth (1.3 g) which was purified by preparative t.l.c! in CHCI3:Me0H (9:1) to give the title compound (1.08 g), [a]D +24°.

INTERMEDIATE 5

2/3-Ethoxy-3a-hydroxy-11 a;-(2,2,2-trichoroethoxycarbonylamino)-5ar-androstane-17/3-carboxylic acid 35 Following the method used,for Intermediate 4 the title compound (680 mg; [a]D +13°) was 35

prepared from Intermediate 3 (2.5 g) using bromine (0.6 ml) and a solution of NaOH (1.75 g) in water (13 ml).

INTERMEDIATE 6

Methyl 2/3-ethoxy-3ar-hydroxy-11a-(2,2,2-trichloroethoxycarbonylamino)-5a-androstane-17/3-40 carboxylate

Potassium carbonate (1.15 g) and methyl iodide (0.8 ml) were added to a solution of Intermediate 5 (1.4 g) in DMF (25 ml) at 0°C. The mixture was stirred for 2 h when the solid was removed by filtration. The filtrate was diluted with water (50 ml) and extracted with ethyl acetate (x2). The extract was washed with brine (x2) and water and dried. Evaporation gave an oil (1.586 g) which was purified 45 by column chromatography eluted with ethyl acetate/petrol (1:2) to give the title compound (1.211 g), [a]D +17.5°.

INTERMEDIATES 7 TO 11

Table 1 summarises the preparation of 17/5-esters using the general method described for Intermediate 6.

50 Intermediate 7 is methyl 3a-hydroxy-11 ar-(2,2,2-trichloroethoxycarbonylamino)-5/3-androstane

1 7/3-carboxylate.

Intermediates 8 to 10 are esters of 2/3-ethoxy-3ar-hydroxy-11 ar-(2,2,2-trichloroethoxycarbonyl-amino)-5a-androstane-17/3-carboxylic acid.

Intermediate 11 is ethyl 11 a-(2,2,2-trichloroethoxycarbonylamino)-5ar-androst-2-ene-17/3-55 carboxylate.

25

30

40

45

- 50

'55

TABLE 1

Inter. No.

Starting Material Inter. No. Wt. (g)

Alkyl Halide reagent

Vol (ml)

k2co3 (g)

Reaction Time (h)

Yield • (9)

mo

7

23

21.9

lodomethane

13.75

19.6

1.5

23.07

+30°

8

5

1.5

1-lodopropane

1.2 .

1.3

17.0

1.54

9

5

1.5

1-Bromo-3-

1.5

1.3

19.0

1.6

10

5

0.62

methyl butane lodoethane

0.5

0.5

1.75

0.35

+12.5"

11

4

0.87

lodoethane

1.4

0.73

1.5

0.7

+25"

9

GB 2 080 308 A 9

INTERMEDIATE 12

Methyl 11 «-(2,2,2-trichloroethoxycarbonylamino)-5a-androst-2-ene-17/5-carboxylate

A solution of Intermediate 4 (1.064 g) in DMF (24 ml) was stirred at 0°C with K2C03 (0.893 g) and methyl iodide (0.67 ml) for 1.5 hour. The mixture was filtered and the filtrate was diluted with water 5 (50 ml) and extracted with ethyl acetate (x3). The extract was washed with brine and water, dried and 5 evaporated to leave a froth (0.798 g) which was purified by preparative t.l.c. using EtOAc:Petrol (1:3) to give the title compound (0.621 g) as a froth, [«]D +26.5°.

INTERMEDIATE 13

Methyl 2y,3ev-epoxy-11 rz-(2,2,2-trichloroethoxycarbonylamino)-5a:-androstane-17/5-carboxylate .10 A solution of Intermediate 12 (12.372 g) in dichloromethane (200 ml) was treated with m- 10

chloroperoxybenzoic acid (6.56 g). After 1 h the reaction mixture was washed with NaHS03 solution, NaHC03 solution and water. The aqueous washes were extracted with dichloromethane and the combined extract was washed with water, dried and evaporated to leave a froth (11.531 g). A portion was purified by preparative t.l.c. in EtOAc/Petrol (1:3) to give the title compound, [a]D +21 °.

15 INTERMEDIATE 14 15

Ethyl 2a,3fv-epoxy-11 o;-(2,2,2-trichloroethoxcarbonyIamino)-5cr-androstane-17/5-carboxylate

Following the method used for Intermediate 13 the title compound (544 mg; [a]D +16°) was prepared from. Intermediate 11 (620 mg) using m-chloroperoxybenzoic acid (319 mg). Purification was effected by preparative t.l.c. using CHCI3:MeOH (19:1).

20 INTERMEDIATE 15 '20

Cyclohexyl 2/3-ethoxy-3a-hydroxy-11 a'-(2,2,2-trichloroethoxycarbonylamino)-5ar-androstane-17/5-carboxylate

A solution of Intermediate 5 (2.2 g) in ether (20 ml) was stirred with cyclohexanol (2.1 ml), dicyclohexylcarbodiimide (0.907 g) and 4-dimethylaminopyridine (0.056 g) for 18 h. Ether (100 ml) 25 was added and the mixture was filtered. The filtrate was washed with 2M-HCI solution (X2), NaHC03 25 solution and brine, dried and evaporated to leave a froth (2.902 g).

INTERMEDIATE 16

Methyl 11 «-amino-2a;,3ar-epoxy-5ar-androstane-17/5-carboxylate

Toluene-4-sulphonic acid (570 mg) was added to a solution of methyl 11 a-amino-5ar-androst-2-30 ene-17/5-carboxylate (1.0 g) in 1,2-dichloroethane (25 ml). After 0.5h m-chloroperoxybenzoic acid (810 30 mg) was added and the mixture was left for a.further 2h. The mixture was washed with NaHS03 solution, 5% NaHC03 solution and water. The aqueous phases were extracted with dichloromethane and the combined organic phase was dried and evaporated to leave a foam which was purified by preparative t.l.c. in MeOH: 0.88 NH2 (50:1) to give the title compound (369 mg) as a foam [a]0 +44°, 35 ,w 1722 cm-1. 35

INTERMEDIATE 17

Methyl 11a-cyclohexylamino-2a,3(i;-epoxy-5a-androstane-17/5-carboxylate.

Cyclohexanone (0.3 ml) and sodium cyanoborohydride (300 mg) were added to a solution of Intermediate 16 (300 mg) in ethanol (8 ml) and the mixture was left for 24 h. 5% NaHC03 solution was 40 added and the mixture was extracted with ether (x3). The extract was washed with water, dried and 40 evaporated to leave a foam which was purified by column chromatography and preparative t.l.c. to give the title compound (80 mg) as a foam [c*]D —2°.

INTERMEDIATE 18

11af-(2,2,2-trichloroethoxycarbonylamino)-3rt-(2,2,2-trichloroethoxycarbonyloxy)-5a-pregnan-20-one 45 A solution of 11 cj'-amino-3Q:-hydroxy-5«:-pregnan-20-one (19.5 g) in dichloromethane (250 ml) 45

and pyridine (26.5 ml) was cooled in an ice-bath during the addition of 2,2,2-trichloroethyl chloroformate (36 ml). On complete addition, water was carefully added and when no further reaction occurred the mixture was washed with 2M-HCI solution (x2) and water. The solution was dried and evaporated to leave an oil (24.6 g) which was treated with ether to give the title compound (14.1 g) as a 50 solid. 50

INTERMEDIATE 19

3rr-Hydroxy-11 a-(2,2,2-trichloroethoxycarbonylamino)-5a-androstane-17/5-carboxylic acid

Following the method used for Intermediate 4 the title compound was prepared from Intermediate 18 (15.5 g) using bromine (3.85 ml) and a solution of NaOH (11 g) in water (85 ml). Purification was 55 effected by column chromatography eluted with EtOAc/Petrol (1:1) to give the title compound (4.73 g). 55 A portion was crystallised from ether/petrol, m.p. dec. 100°C, [a]D +19°.

3

GB 2 080 308 A 10

INTERMEDIATE 20

Methyl 3a-hydroxy-11 ar-(2,2,2-trichloroethoxycarbonylamino)-5a:-androstane-17/5-carboxylate

A solution of Intermediate 19 (4 g) in DMF (80 ml) was stirred with K2C03 (3.7 g) at 0°C. Methyl iodide (2.6 ml) was added and the mixture was stirred for 2 h. Water (300 ml) was added and the 5 mixture was extracted with ether (x3). The extract was washed with water, dried and evaporated to 5 leave a froth which was purified by column chromatography eluted with EtOAc/petrol (1:2) and crystallised from ether to give the title compound (2.45 g), m.p. 167—170°C, [cr]D +25°.

INTERMEDIATE 21

Methyl 3a-hydroxy-2/5-methoxy-11 a:-(2,2,2-trichloroethoxycarbonylamino)-5a-androstane-17/5-3 carboxylate 10

Boron trifluoride diethyl etherate (11.3 ml) was added to a solution of Intermediate 13 (5.266 g) in methanol (60 ml) and the mixture was stirred at room temperature for 1 h. The mixture was diluted with 5% NaHC03 solution and extracted with ethyl acetate (x3). The extract was washed with water, dried and evaporated to leave a froth. A portion (193 mg) was purified by preparative t.l.c. using ethyl 5 acetate/petrol (1:1) to give the title compound (144 mg) as a froth, [a]D +23°, vmax 1722 cm-1. 15

INTERMEDIATE 22

11 cr-(2,2,2-Trichloroethoxycarbonylamino)-3a:-[2,2,2-trichloroethoxycarbonyloxy)-5/3-pregnan-20-one

Pyridine (39 ml) and 2,2,2-trichloroethyl chloroformate (53 ml) were added to an ice-cooled solution of 11 a-amino-3a-hyclroxy-5/3-pregnan-20-one (26.54 g) in dichloromethane (350 ml). After 0 2 h water (400 ml) was added and the organic phase was separated and evaporated to leave a brown 20 oil which crystallised on trituration with ether/petrol to give the title compound (47.86 g), m.p.

174—176°C, [a]D +60°.

INTERMEDIATE 23

3a-Hydroxy-11a~(2,2,2-trichloroethoxycarbonylamino)-5/5-androstane~17/5-carboxylic acid 5 Following the method used for Intermediate 4, bromine (12.5 ml) and a solution of sodium 25

hydroxide (35.1 g) in water (270 ml) was used to convert Intermediate 22 (47 g) into the corresponding 17/3-carboxylic acid which was then taken up in dioxan. 2M-NaOH solution was added to give a pH 11 and the mixture was stirred for 3 h. The mixture was brought to pH 2 with concentrated HCI solution and diluted with water. The precipitate was extracted with chloroform (x2) and the extract was washed 0 with water, dried and evaporated to leave an oil which crystallised from ether/petrol to give the title 30 i compound (22.5 g), m.p. 250—251 °C, [a]D +34°.

INTERMEDIATES 24—28

Table 2 summarises the preparation of 2/5-substituted compounds from the corresponding 2a,3a-epoxide using the general method described for Intermediate 21.

>5 Intermediate 24 is ethyl 2/5-butoxy-3ar-hydroxy-11a-(2,2,2-trichloroethoxycarbonylamino)-5a- 35 androstane-17/5-carboxylate.

Intermediates 25—28 are 2/5-alkoxy analogues of Intermediate 21.

TABLE 2

Starting Material

Alcohol

BF3.Et20 (ml)

Reaction Time (h)

Yield (9)

■

Inter. No.

Inter No.

wt. (g)

reagent

Vol. (ml)

[«]D

24

14

0.46

Butan-1-ol

5.2

1.0

1

0.38

+11°

25

13

3.17

Butan-1-ol

36.0

6.83

1

3.46

+15°

26

13

3.89

Pentan-1-ol

50.0

8.8

24

3.40

+14°

27

13

4.21

Hexan-1-ol

50.0

10.0

20

5.33

-t9°

28

13

5.22

Propan-1-ol

59.0

11.2

1

-

+20°

12

GB 2 080 308 A 12

INTERMEDIATE 29

11a-(2,2,2-Trichloroethoxycarbonylamino)-3/3-(2,2,2-trichIoroethoxycarbonyioxy)-5f.tr-pregnan-20-one Pyridine (12 ml) and 2,2,2-trichloroethyl chloroformate (40 ml) were added to a cooled, stirred : solution of 11 a-amino-3/3-hydroxy-5n:-pregnan-20-one (24 g) in dichloromethane (300 ml). After 2 h 5 water (300 ml) was added and the organic phase was separated and the solvent removed by 5

evaporation to leave an oil which was purified by column chromatography eluted with ethyl acetate/petrol (1:4) and (1:2) to give the title compound (27.27 g), [a-]D +40°.

INTERMEDIATE 30

3/5-Hydroxy-11 a-(2,2,2-trichloroethoxycarbonylamino)-5ar-androstane-17/3-carboxylic acid 10 Following the method used for Intermediate 4 the title compound [\ 8.17 g;m.p.212—220°C; 10

[«]D +16°) was prepared from Intermediate 29 (27 g) using bromine (7.2 ml) and a solution of NaOH (20 g) in water (155 ml). The product was crystallised from ether/petrol.

INTERMEDIATE 31

Methyl 3/3-hydroxy-11 ar-(2,2,2-trichloroethoxycarbonylamino)-5ar-androstane-17/3-carboxylate 15 Potassium carbonate (16 g) and methyl iodide (11.2 mi) were added to a stirred solution of 15

Intermediate 30 (17.8 g) in DMF (325 ml) at 0°C. After 1.75 h the mixture was diluted with water (1.5 I) and the precipitate was extracted with ethyl acetate (x2). The extract was washed with brine (x2),

dried and evaporated to leave an oil which on evaporation from ether gave the title compound (15.45 g) la]D+15°.

20 INTERMEDIATE 32 20

Methyl .11<*-amino-3/3-hydroxy-5nr-androstane-17/3-carboxylate

Zinc powder (36 g) was added to a stirred solution of Intermediate 31 (1 5 g) in glacial acetic acid (400 ml). The mixture was stirred for 20 h and the zinc was removed by filtration and washed with water. The filtrate was reduced in bulk in vacuo and the residue was brought to pH 10 with 0.88 NH3 25 solution. The oil was extracted with ethyl acetate (x2) and the extract was washed with brine (x2), 25 dried and evaporated to leave an oil (7.93 g). A sample (400 mg) was purified by preparative t.l.c. to give the title compound as a froth [a]D +29°.

INTERMEDIATE 33

Methyl 11 a-cyclohexylamino-3/3-hydroxy-5or-androstane-17/3-carboxylate 30 Sodium cyanoborohydride (7.5 g) and cyclohexanone (12 ml) were added to a stirred solution of 30

Intermediate 32 (7.5 g) in ethanol (100 ml). After 60 h the mixture was diluted with 5% NaHC03 solution (100 ml) and the resultant precipitate was extracted into ether (x2). The extract was shaken with 2M-HCI (x2) and the aqueous phase was washed with ether, brought to pH 9 with 0.88 NH3 solution and extracted with ether (x2). The extract was washed with water (x2), dried and evaporated • 35 to a froth which was purified by column chromatography on silica eluted with CHCI3:Me0H (19:1) to 35 give the title compound (4.411 g) which crystallised from petrol m.p. 82—84°C, [a]D —1 °.

INTERMEDIATE 34

Methyl 11 ar-cyclohexylamino-3-oxo-5ar-androstane-17/3-carboxylate

Jones reagent was added dropwise to a stirred solution of methyl 11 ar-cyclohexylamino-3/3-40 hydroxy-5«-androstane-17/3-carboxylate (300 mg) in acetone (40 ml) until the reagent colour was not 40 discharged. Water (200 ml) was added and the mixture was brought to pH 10 with 0.88 NH3 solution.

Ether (50ml) was added and the mixture was filtered. The aqueous phase was separated, extracted with ether (50 ml) and the organic phase was washed with water, dried and evaporated to leave an oil (289 mg) which crystallised from petrol to give the title compound m.p. 93—94°C, [n-]D —12°.

45 INTERMEDIATE 35 45 .

3a-Hydroxy-11 -hydroxyimino-5a:-androstane-17/3-carboxylic acid

Hydroxylamine hydrochloride (4 g) was added to a water cooled solution of sodium hydroxide (50%; 16 ml). This mixture was added to a solution of 3ar-hydroxy-11 -oxo-5a'-androstane-17/3-carboxylic acid (1.5 g) in ethanol (70 ml). The mixture was heated at reflux for 24 h, cooled and brought 50 to pH 1 with concentrated HCI solution. Water (800 ml) was added and the precipitate (1.42 g) was 50 collected by filtration, washed with water (2x300 ml) and dried. Crystallisation from ethyl acetate gave the title Compound(1 g) m.p. 250—253°C (dec) [or]D +124° (EtOH C = 1%).

INTERMEDIATE 36

11 cr-Cyclohexylamino-2/3-ethoxy-3o'-hydroxy-5flf-pregnan-20-one 55 A solution of 11 rr-amino-2/3-ethoxy-3fT-hydroxy-5r*-pregnan-20-one 20-ethyiene acetal (2 g) in ethanol (20 ml) was stirred with cyclohexanone (1.5 ml) and sodium cyanoborohydride (2.01 5 g) for 6 h. 5% NaHCOg solution (40 ml) was added and the mixture was extracted with ether (x2). The extract was washed with, water (x2), dried and evaporated to leave a froth which was dissolved

55

13

GB 2 080 308 A 13

solution (50 ml) and ethanol (50 ml). Water (100 ml) was added and the mixture was washed with ether (x2). The wash was extracted with 2M-HCI solution and the combined acid fraction was brought to basic pH with 2M-NaOH solution. The mixture was extracted with ether (x2) and the extract was washed with water (x2), dried and evaporated to leave a froth which was purified by column 5 chromatography eluted with CHCI3:Me0H (9:1) to give the title compound (1.235 g), [ar]D +39°. t>max 5 1695 cm-1.

INTERMEDIATE 37

Methyl 2/5-acetoxy-3a-hydroxy-11o,-(2,2,2-trichloroethoxycarbonylamino)-5rt'-androstane-17/3-carboxylate

^0 Intermediate 13 (20.5 g) in glacial acetic acid (100 mi) was heated on a steam bath for 3.25 h. 10

The reaction mixture was allowed to cool, concentrated by evaporation and then diluted with 0.88 NH3 solution to pH 9.0. This was extracted with ethyl acetate (3x). The extracts were washed with water (1 x), dried and evaporated to a foam (23.8 g). A small sample was purified by preparative t.l.c. in EtOAc/Petrol (1:1) and crystallised from ether to give the title compound (220 mg), m.p. 200—201 °C, 15 [o-Id +26.1 °. 15

INTERMEDIATE 38

2/3-Ethoxy-3a-hydroxy-11 a-(3-methylbutylamino)-5o'-pregnan-20-one

11tt-amino-2/3-ethoxy-3ar-hydroxy-5ar-pregnan-20-one 20-ethylene acetal (20 g) in ethanol (200 ml) was stirred with K2C03 (25 g), Nal (1 g) and 1-bromo-3-methylbutane (50 ml) and the mixture was 20 heated at reflux for 24 h. The excess K2C03 was removed by filtration and washed with ethanol. The 20 filtrate and washings were acidified with 2M-HCI to pH 2, washed with ether and the ether wash in turn washed with M-HCI and water (x3). The aqueous layers were brought to pH 10 with 2M-Na0H and the resulting suspension was extracted with ether (x2). The ether layers were combined, washed with water (x2), dried and evaporated to leave a froth (18.96 g), which was purified by column 25 chromatography eluted with CHCL/MeOH (19:1) and crystallised from acetonitrile to give the title 25

compound(9.211 g), m.p. 110.5—112°C, [a]D +56°.

EXAMPLES — SECTION A

EXAMPLE 1

Methyl 11.a-amino-2/3-ethoxy-3a;-hydroxy-5ar-androstane-17/3-carboxylate 30 Zinc powder (2.4 g) was added to a stirred solution of Intermediate 6 (1.1 g) in glacial acetic acid 30

(25 ml) and the mixture was stirred for 6 hours. The zinc was removed by filtration and washed with water. The aqueous filtrate was washed with ether (x2) then brought to pH 10 with 2M-Na0H solution. The mixture was extracted with ether (x2) and the extract was washed with water (x2), dried and evaporated to leave an oii (580 mg) which was purified by preparative t.l.c. using methanol to give the 35 title compound^ 80 mg), [a]D +46°. i>max 1725 cm-1. 35

EXAMPLE 2

Methyl 11ar-amino-3a-hydroxy-5ar-androstane-17/3-carboxylate

A solution of Intermediate 20 (2.4 g) in glacial acetic acid (25 ml) was stirred with zinc (2.5 g) for 4 hours. The zinc was removed by filtration and washed with water (50 ml) and ether (50 ml). The ^•0 filtrate and washings were brought to pH 10 with 0.88 NH3 solution and extracted with ether (x4). The 40 extract was washed with water, dried and evaporated to leave a solid (1.65 g). A portion was crystallised from ether to give the title compound, m.p. 113—116°C, [a]D +38°.

' EXAMPLE 3

Methyl 11 ar-amino-3(T-hydroxy-2/3-methoxy-5rr-androstane-17/3-carboxylate 45 Zinc powder (4.9 g) was added to a stirred solution of Intermediate 21 (4.874 g) in glacial acetic 45

acid (15 ml) and the mixture was stirred for 1 h. The zinc was removed by filtration and washed with water. The filtrate and washings were brought to pH 10 with 0.88 NH3 solution and extracted with ether (x3). The extract was washed with water, dried and evaporated to leave a solid which was crystallised from ethyl acetate to give the title compound (1.716 g), m.p. 177—184°C, [o]D +53°.

50 EXAMPLES 4—16 50

Table 3 summarises the preparation of 11 rt-amino compounds from the corresponding 11 n-

(2,2,2-trichloroethoxycarbonylamino)-compounds using the general method described in Example

1—3.

Purification was effected by preparative t.l.c. (P), column chromatography (C) or crystallisation (X).

55 The compounds prepared were as follows: 55

4. Ethyl 11rt'-amino-2/3-ethoxy-3«-hydroxy-5cj'-androstane-17/3-carboxylate,

5. 3-Methylbutyl 11 (r-amino-2/3-ethoxy-3<r-hydroxy-5(T-androstane-17/3-carboxylate,

6. Propyl 11 «r-amino-2/3-ethoxy-3or-hydroxy-5fi;-androstane-17/3-carboxylate,

14

GB 2 080 308 A 14

7. Ethyl 11ar-amino-2/3-butoxy-3ar-hydroxy-5a-androstane-17/3-carboxylate,

8. Methyl 11a-amino-2/3-butoxy-3a;-hydroxy-5ar-androstane-17/3-carboxylate,

9. Methyl 11a-amino-3a;-hydroxy-2/}-pentyloxy-5a:-androstane-17/3-carboxylate,

10. Methyl 11 a-amino-2/3-hexyloxy-3or-hydroxy-5a-androstane-17/3-carboxylate,

5 11. Cyclohexyl 11 ar-amino-2/3-ethoxy-3a;-hydroxy-5a-androstane-17/3-carboxylate, 5

12. Methyl 11 ar-amino-3a-hydroxy-2/3-propoxy-5a:-androstane-17/3-carboxylate,

i 13. MethyM 1ar-amino-3a;-hydroxy-5/3-androstane-17/3-carboxylate,

14. Methyl 2/3-acetoxy-11 a-amino-3a;-hydroxy-5a'-androstane-17/3-carboxylate.

TABLE 3

Example No.

Starting Material

Zinc

(g)

Acetic Acid (ml)

Reaction Time (h)

Purification System

Yield (g)

M.P./ Kmax

Inter. No.

wt. (g)

MD

42

10

1.225

2.4

25

6

P - M

0.391

+39.5°

1720 cm'1

51

9

1.61

3.0

25

7.5

X-A

0.573

+36°

122-124°

6

8

1.54

3.0

35

3.5

P—Ch:M (9:1); X-A

0.341

+40°

130-135°

71

24

3.305

3.3

10

3

P-Ch:M (5:1) and l:Am (40:1)

0.428

+31°

1715 cm?"1

8

25

3.04

3.0

10

3

P - l:Am (40:1)

1.8

+35°

1725 cri^1

9

26

3.106

3.1

20

18

P - I:Am (40:1)

1.8

+33°

1730 cm;1

10

27

4.923

4.9

25

18

P — M:Am (50:1)

3.2

+33°

1724 cm^1

111

15

2.902

3.9

50

7

C - E:M (3:1)

0.321

+33°

1712 cm*1

12

28

5.247

5.2

15

1

P - l:Am (40:1)

0.3893

+42°

1719 cm*1 ,

131

7

22

52.5

600

20

-

13.56

+36°

-

14

37

22.85

22

100

22

X - D

4.534

+49.9°

158-160°

•Ethyl acetate used in place of ether for extraction.

2The ethereal washes were also extracted and the extracts combined.

^nly a portion of the product was purified.

16

GB 2 080 308 A 16

EXAMPLE 15

2/5-Ethoxy-3a:-hydroxy-11 ar-(3-methylbutylamino)-5a;-androstane-17/3-carboxylic acid

A solution of the product of Example B1 (500 mg) in dioxan (10 ml) was heated at 100°C with concentrated hydrochloric acid (1.5 ml) and water (5 ml) for 5 days. The cooled mixture was brought to 5 pH 11 with 50% aqueous sodium hydroxide solution and extracted with ether (x3). The extract was 5 washed with water, dried.and evaporated to leave the title compound as a solid, [<r]D +54°, rmax 1635 cm-1,1550 cm-1.

A sample (20 mg) of this product was dissolved in methanol (1 ml) and the solution was heated at reflux with concentrated sulphuric acid (1 drop) for 4 hours, t.l.c. of the Reaction mixture showed 10 formation of methyl 2/3-ethoxy-3a-hydroxy-11 ar-(3-methyl-butylamino)-5ar-androstane-17/3- 10

carboxylate.

EXAMPLE 16

Methyl 11ar-amino-3a;-hydroxy-5a;-androstane-17/3-carboxylate

Sodium (1 g) was added to a refluxing solution of Intermediate 35 (0.3 g) in propan-1 -ol (20 ml). 15 When all the sodium had been consumed water (10 ml) was added. The mixture was evaporated and 15 the residue was dissolved in 2M-HCI (20 ml). The solution was evaporated to dryness and azeotroped with benzene (x3). The resultant oil was dissolved in methanol (30 ml) and the solution was heated at reflux with concentrated H2S04 (0.5 ml) for 3 h. The cooled mixture was brought to basic pH with 0.88 NH3 solution and diluted with water (100 ml). The precipitate was extracted with ether (x2) and the 20 extract was washed with water, dried and evaporated to leave a froth which was dissolved in ether (50 20 mi). The solution was extracted with 2M-HCI solution (x2) and water. The aqueous extract was brought to pH 10 with 0.88 NH3 solution and the precipitate was extracted with ether (x3). The extract was washed with water, dried and evaporated to leave the title compound (226 mg) as a froth [tt]D +35°.

EXAMPLE 17

25 2/3-Ethoxy-3ar-hydroxy-11a-(3-methylbutylamino)-5a-androstane-17/3-carboxylic acid 25

Bromine (0.4 ml) was added to a solution of sodium hydroxide (1.24 g) in water (16 ml) at 0°C.

Dioxan (6 ml) was added and the mixture was added to a solution of Intermediate 38 (1.14 g) in dioxan (50 ml) and water (16 ml) at 10°C. After 6 h sodium metabisulphite (10 g) was added and the mixture was stirred for 0.5 h. Concentrated HCI solution was added to bring the pH to 1 and the mixture was 30 evaporated to dryness. The solid was leached with ether and ethyl acetate and the solutions evaporated 30 to leave the title compound as a solid (1.31 g).

EXAMPLES 18—26

Table 4 summarises the preparation of the hydrochloride salts of the 11 a-amines.

A solution of hydrochloric acid in water was added to the base or a suspension of the base in any 35 additional water and the mixture was stirred or shaken until either a clear solution was obtained or no 35 more base dissolved. The mixture was made up to the appropriate weight or volume with water and filtered and any undissolved base was collected, dried and weighed to determine the solution concentration. The pH was measured.

TABLE 4

Example No.

Example No. of free base

Wt.

(mg)

HCI

M

Vol. (ml)

Additional Water (ml) •

Total Weight or Volume

Solid residue (mg)

pH

Conc'n. (%)

18

1"

100

0.0963

2.7

3

10 ml

-

2.4

1

19

4

100

0.0963

2.55

3

10 ml

-

3.1

1

20

6

100

0.0963

2.46

2

10 ml

-

5.0

1

21

5

100

0.0963

2.35

3

20 ml

-

3.2

0.5

22

7

349.8

0.0924

7.42

20

30 ml

10.8

6.0

1.13

23

8

375.6

0.0924

9.64

-

30.02g

-

2.4

1.25

24

9

175.7

0.0924

4.36

-

10.04g

-

2.3

1.75

25

10

518.3

0.0924

12.47

-

50.05g

63

2.55

0.9

26

17

100

0.0924

2.4

-

10 ml

-

2.7

1

8

GB 2 080 308 A 18

EXAMPLES — SECTION B EXAMPLE 1

Methyl 2/3-e thoxy-3ar-hydroxy-11 ar-(3-methylbutylamino)-5a;-androstane-17/5-carboxylate

Potassium carbonate (2i514 g), sodium iodide (107 mg) and 1-bromo-3-methylbutane (6 ml)

5 were added to a stirred solution of the product of Example A1 (2 g) in ethanol (30 ml) and the mixture 5 was heated at reflux for 24 hours. The reaction was cooled and acidified with 2M-HCI solution and washed with ether. The ethereal wash was extracted with M-HCI solution and water (x2). The total aqueous phase was brought to pH 10 with 2M-Na0H solution and extracted with ether (x2).The extract was washed with water (x2) dried and evaporated to leave an oil which was purified by 0 crystallisation from acetonitrile to give the title compound (914 mg), m.p. 122—124°C, [a]D +22°. 10

EXAMPLE 2

Methyl 3a-hydroxy-2/5-methoxy-11 a-(3-methylbutylamino)-5ar-androstane-17/3-carboxylate

1-Bromo-3-methylbutane (9.54 ml), potassium carbonate (2.94 g) and sodium iodide (0.111 g)

were added to a stirred solution of the product of Example A3 (2.408 g) in ethanol (43 ml) and the 5 mixture was heated at reflux for 22 h. The cooled mixture was diluted with water and extracted with 15 ethyl acetate (x3). The extract was washed with water, dried and evaporated to a froth which was purified by preparative t.l.c. using CHCI3:Me0H (19:1) to give the title compound (1.24 g), [a]D +22°, I72*cm"1.

EXAMPLES 3—10

;0 Table 5 summarises the preparation of 11 a-alkylamino compounds from the corresponding 11a- 20 amines using the general method of Examples 1 and 2. Work up was either as in Example 1 (I) or in Example 2 (ID-

Purification was effected by preparative tl.c. (P), column chromatography (C) or crystallisation (X). In Examples 3—7 and 9 the haloalkane was 1-bromo-3-methylbutane, in Example 8 it was !5 iodopropane and in Example 10 it was 1 -iodo-3-methylbutane. 25

The compounds prepared were as follows:

3. Ethyl 2/3-ethoxy-3-hydroxy-11 a-(3-methylbutylamino)-5a-androstane-17/3-carboxylate,

4. Methyl 2/3-butoxy-3a-hydroxy-11 a-(3-methylbutylamino)-5a-androstane-17/3-carboxylate,

5. Methyl 3a-hydroxy-11 or-(3-methylbutylamino)-2/3-pentyloxy-5a:-androstane-17/3-carboxylate,

10 6. Methyl 2/3-hexyloxy-3a:-hydroxy-11a-(3-methylbutylamino)-5ar-androstane-17/3-carboxylate, 30

7. Methyl 3ar-hydroxy-11 a-(3-methylbutylamino)-5ar-androstane-17/3-carboxylate,

8. Methyl 2/3-ethoxy-3a-hydroxy-11 a;-propylamino-5ar-androstane-17/3-carboxylate

9. Methyl 3a-hydroxy-2/3-propoxy-11 a-(3-methylbutylamino)-5ar-androstane-17/3-carboxylate, 10. Methyl 3ar-hydroxy-11ar-(3-methylbutylamino)-5/3-androstane-17/3-carboxylate.

table 5

Ex. No.

Starting Material

Ex. wt. No. (g)

Ethanol (ml)

Haloalkane (ml)

k2co3 (g)

Nal

(mg) .

Reaction Time (h)

Work up method

Purification System

Yield

(g)

[«]D

MP/ ^max

3

A4

2.02

30

6

2.51

105

24

I

C—Ch:M (9:1) X-A

1.0

+ 18.5°

100-102°

4

A8

0.87

15

3.35

1.03

39

32

II

P—Ea:Pe (1:1)

0.39

+16°

1722 cm"1

5

A9

0.91

16

3.5

1.03

41

24

II

P—Ea:Pe (1:2)

0.31

+17°

1720 cm"1

6

A10

1.78

30

6.8

2.1

80

22

II

P-Ea

0.76

+ o

-

7

A2

1.6

30

5

2.3

-

24

II1

,P-Ch:M (9:1) and D

0.46

+18°

1725 cm*1

8

A1

2.5

30

9

3.5

-

7.5

1

P and C — Ch:M (9:1)

1.36

+24°

1722 cm*

9

A12

2.66

46

10.2

3.14

119

21

II

P—Ch:M (19:1)

0.83

cn o

1724 cm41

10

A13

6

a o o

M

6.5

8.65

-

50

1

P-Ch:M (9:1)

0.553

+8°

1726 cmk

'Diethyl ether used in place of ethyl acetate.

2Dioxan used in place of ethanol.

*Only a portion of the product was purified.

20

GB 2 080 308 A 20

EXAMPLE 11

Methyl 11 ar-cyclohexylamino-3ar-hydroxy-2/3-methoxy-5a-androstane-17/3-carboxylate

A suspension of the product of Example A3 (1.512 g) in ethanol (1 5 ml) and cyclohexanone (1.5 ml) was stirred with sodium cyanoborohydride (1.5 g) for 24 h. 5% NaHC03 solution was added and 5 then water. The mixture was extracted with ether (x2) and the extract was washed with water, dried and 5

evaporated to leave a froth which was purified by column chromatography using chloroform:methanol (19:1) and crystallised from acetonitrile to give the title compound) (1.069 g), m.p. 143—145°C,

[a]D +9.5°.

EXAMPLE 12

10 Methyl 11a-cyclohexylamino-3a;-hydroxy-5a:-androstane-17/}-carboxylate 10

Sodium cyanoborohydride (2 g) was added to a mixture of the product of Example A2 (2 g) and cyclohexanone (2.5 ml) in ethanol (30 ml). The mixture was kept at 21 °C for 5 h. 5% NaHC03 solution and water were added and the mixture was extracted with ether (x2). The extract was washed with water, dried and evaporated to leave a froth which was purified by column and preparative layer 15 chromatography using CHCI3:MeOH (9:1) to give the title compound (0.763 g) as a froth, [a]0 +6°, vmm 15-1720 cm"1.

EXAMPLES 13—25

Table 6 summarises the preparation of 11 ar-alkylamino compounds from the corresponding 11 oe-amines using the general method of Examples 11 and 12. '

20 The aldehydes/ketones uaws in Examples 13—25 were as follows: cyclohexanone (Examples 13, 20 15,20 and 22); cyclopentanone (Examples 16 and 17); 3,3-dimethylbutyraldehyde (Example 14); hexaldehyde (Example 18); 4-methylpentanal (Example 19); 3-methylbutanai (Example 21 );

cycloheptanone (Example 23); cyclobutanone (Example 24) and acetone (Example 25).

Purification was effected by Preparative tl.c. (P), column chromatography (C) or crystallisation (X). 25 The following compounds were prepared: 25

13. Ethyl 11a-cyclohexyIamino-2/3-ethyoxy-3a-hydroxy-5ar-androstane-17/3-carboxylate,

14. Methyl 11 a:-(3,3-dimethylbutylamino)-2/3-ethoxy-3a-hydroxy-5a-androstane-17/3-carboxylate,

15. Methyl 11 a-cyclohexylamino-2/3-ethoxy-3a-hydroxy-5a:-androstane-17/3-carboxylate,

16. Methyl 11 a-cycIopentylamino-3a-hydroxy-5ar-androstane-17/3-carboxylate,

30 17. Methyl 11a:-cyclopentylamino-3a-hydroxy-2/3-methoxy-5a:-androstane-17/3-carboxylate, 30

18. Methyl 2/3-ethoxy-11 a-hexylamino-3a-hydroxy-5a-androstane-17/5-carboxylate,

19. Methyl 2/3-ethoxy-3a-hydroxy-11 a-(4-methylpentylamino)-5a:-androstane-i 7/3-carboxylate,

20. Methyl 11 a-cyclohexylamino-3a-hydroxy-5a;-androstane-17/3-carboxylate,

21. Methyl 2/3-acetoxy-3a-hydroxy-11 a-(3-methylbutylamino)-5a-androstane-17/3-carboxylate,

35 22. Methyl 2/3-acetoxy-11a-cyclohexylamino-3a-hydroxy-5a-androstane-17/3-carboxylate, 35

23. Methyi 11a;-cycloheptylamino-3ar-hydroxy-2/3-methoxy-5a:-androstane-17/3-carboxylate,

24. Methyl 11 a-cyclobutylamino-3a:-hydroxy~2/3-methoxy-5ar-androstane-17/3-carboxylate,

25. Methyl 2/3-ethoxy-3ar-hydroxy-11a;-(1-methylethylamino)-5ar-androstane-17/3-carboxylate.

TABLE 6

Ex. No.

Starting Material

Ethanol (ml)

Aldehyde/ Ketone (ml)

NaBHjCN

(g)

Reaction Time (h)

Purification System

Yield (9)

m.p./ ^max

Ex. No.

Wt. (g)

Md

13*

A4

2.0

20

2.5

3.07

27

C-Ch:M (19:1) X-A

1.31

+5°

109-115° C

14

A1

2.5

25

1.5

2.63

17

C—Ch'-M (19:1) X-A

1.01

+16°

82.5-85.5° C

15 .

A1

2.5

25

2.6

2.57

20

C—Ch:M (19:1) X-A

1.51

+6°

111—114°C

162

A2

2.0

20

2.0

2.0

19

C and P Ch:M (9:1)

1.47

+12°

1724 cm"1

173

A3

0.96

10

1.0

1.5

23

X-A

0.62

+16.5°

130-132° C

18

A1

2.49

30

2.0

2.49

2

C-Ch:M (19.1) X-A

1.12

+21°

108—109°C

191

A1

2.61

20

3.0

2.40

70

X-A

1.04

+21°

123—125°C

20

A13

2.51

30

2.9

2.51

5

P-Ch:M (19:1)

2.54

-9°

1725 cmM

21

A14

2.85

40

4.2

3.0

20

C—Ch:M (9:1) X-A

0.274

+24.2°

117—120°C

22

A14

4.08

40

4.0

4.0

27

C—Ch'.M (19:1)

0.86

+10.6°

1722 cmf1

23s

A3

2.7

27

2.7

2.7

45.5

C—Ch:M (19.1) P-Ch:M (9:1) X-A

0.43

+8°

100-103°C

•24

A3

2.8

30

1.0

2.8

47

C—Ch:M (19:1) P—Ch:M (9:1)

0.64

+26°

1720 cm?"1

25

A1

1.0

15

6.0

1.0

94

C-Ch:M (19:1)

0.44

+16.5°

1723 cmt-1

1 An additional work up was used, as follows:

The product after evaporation of the ether extract was dissolved in 2IV1—HCI, water and ethanol and the solution washed with ether. The ethereal wash was extracted with M—HCI and water and the total aqueous phase brought to pH 10 with 0.88 NH3 solution and extracted with ether. The extract was then washed, dried and evaporated to give a residue which was subjected to purification.

2 Sodium borohydride (0.05 g) added after 18h.

3 Sodium borohydride (0.01 g) added after 22h.

4 Only a portion of the product was purified.

5 Sodium borohydride (0.15 g) added after 45ti.

22

GB 2 080 308 A 22

EXAMPLE 26

Propyl 2/5-eth oxy-3 a-hyd roxy-11 a-(3-methylbutylamino)-5a-androstane-17/5-carboxylate

A solution of the product of Example B1 (0.9 g) is propan-1-oi (20 ml) was heated at 100°C with concentrated H2S04 (4 ml) for 24 h. The cooled mixture was brought to pH 9 with 5% NaHC03 solution 5 and extracted with ether (x2). The extract was washed with water, dried and evaporated to leave an oil which was purified by preparative t.l.c. using chloroform:methanol (9:1) to give the title compound (0.612 g) as an oil, [a]D +22°, umax 1720 cm-1.

EXAMPLE 27

Cyclohexyl 2 /J-ethoxy-3 or-hyd roxy-11a-(3-methylbutylamino)-5ar-androstane-17/3-carboxylate 10 A solution of the product of Example B1 (4.26 g) in cyclohexanol (30 ml) was stirred at 110°C

with concentrated H2S04 (2 ml) for 18 h. The mixture was brought to basic pH with 0.88 NH3 solution and extracted with ether (2x). The extract was washed with water, dried and evaporated to leave an oil which was purified by column chromatography eluted with EtOAc/MeOH (3:1) and CHCI3:Me0H (19:1) to give the title compound (857 mg) [a]D +11°, vmax 1713 cm-1.

15 EXAMPLE 28

Methyl 11 a-cyclohexylamino:2/5-ethoxy-3a-hydroxy-5a-androstane-17/3-carboxylate

Bromine (0.44 ml was added to a stirred solution of sodium hydroxide (1.24 g) in water (8 ml) at 0°C. Dioxan (4 ml) was added and this mixture was added to a solution of Intermediate 36 (0.584 g) in dioxan (25 ml) and water (8 ml) at 10°C. The mixture was stirred at room temperature for 3 h. Sodium 20 metabisulphite (2 g) was added and after 10 minutes the mixture was diluted with water (100 ml). The solvents were removed by evaporation to leave a solid which was dissolved in methanol (30 ml) and the solution was heated at reflux with concentrated H2C04 (1 ml) for 5 h. The mixture was brought to pH 10 with 0.88 NH3 solution and diluted with water (150 ml). The precipitate was extracted with ether (x3) and the extract was washed with water (100 ml), dried and evaporated to leave an oil which was 25 purified by column chromatography eluted with CHCl3:Me0H (9:1) to leave an oil which was crystallised from acetonitrile to give the title compound (0.235 g), m.p. and mixed m.p. 110—112°C, [a]D +13°.

EXAMPLE 29 ,

Methyl 2/5-ethoxy-3«-hydroxy-11 a-(3-methylbutyIamino)-5or-androstane-17/5-carboxylate

Methanol (2 ml) and dicyclohexylcarbodiimide (100 mg) were added to a stirred mixture of the 30 product of Example A17 (221 mg) in ether (20 ml) to give a solution. 4-Dimethylaminopyridine (10 mg) was added and the mixture was stirred for 72 h. The mixture was filtered and the filtrate was evaporated to leave a froth. This was purified by column chromatography on silica eluted with CHCI3:MeOH (19:1) to give the title compound (130 mg) which crystallised from acetonitrile, m.p. 123—125°C, [qt]d +18°.

35 EXAMPLE 30

Methyl 2/5-ethoxy-3a-hydroxy-11 a-(3-methylbutylamino)-5o:-androstane-17y3-carboxylate Concentrated H2S04 (10 drops) was added to a solution of the product of Example B3 (75 mg) in ; methanol (3 ml) and the mixture was brought to reflux and heated for 6h. The cooled mixture was brought to pH 10 with 0.88 NH3 solution, diluted with water (50 ml) and extracted with ether (x3). The 40 extract was washed with water, dried and evaporated to leave an oil (70 mg) which was crystallised from acetonitrile to give the title compound (AO mg) m.p. and mixed m.p. 123—125°C, [a]D +21 °.

EXAMPLE 31

Methyl 2/5-eth oxy-3 a-h yd roxy-11 a-(3-methylbutylamino)-5ar-androstane-17/5-carboxylate

A solution of diazomethane in ether was added to a solution of the product of Example A17 (550 45 mg) in ether (20 ml) and tetrahydrofuran (20 ml). After 0.5 h glacial acetic acid (2 drops) was added and the mixture was brought to pH 10 with 0.88 NH3 solution and diluted with water (100 ml). The organic phase was washed with water and the combined aqueous phase was extracted with ether. The total organic phase was washed with water, dried and evaporated to leave an oil which was purified by column chromatography eluted with CHCI3:MeOH (19:1) and the product was crystallised from 50 acetonitrile to give the title compound (57 mg) m.p. 123—125°C, [a;]D +21 °.

EXAMPLE 32

Methyl 2/5-ethoxy-3a-hydroxy-11 a-(3-methylbutylamino)-5a:-androstane-17/3-carboxylate

Concentrated H2S04 (1 ml) was added to a solution of the product of Example A17 (500 mg) in methanol (20 ml) and the mixture was heated at reflux for 6 h. The cooled mixture was brought to pH 55 10 with 0.88 NH3 solution and diluted with water (150 ml). The precipitate was extracted with ether (x3) and the extract was washed with water, dried and evaporated to leave an oil which was crystallised from acetonitrile to give the title compound (245 mg) m.p. 123—125°C [qtJd +23°.

5

10

15

20

25

30

35

40

45

50

55

23

GB 2 080 308 A 23

EXAMPLE 33

Methyl 11 ar-cyclohexylamino-3a;-hydroxy-2/}-methoxy-5a;-androstane-17/5-carboxylate

Boron trifluoride diethyl etherate (0.2 ml) was added to a suspension of Intermediate 17 (354 mg) in methanol (5 ml). The mixture was stirred for 1.75 h, diluted with 5% NaHC03 solution and extracted 5 with ether (x3). The extract was washed with water, dried and evaporated to leave a foam which was ' 5 purified by preparative t.l.c. in CHCI3:MeOH (9:1) to give a foam which crystallised from acetonitrile to give the title compound(56 mg) m.p. 141—143°C, [a]0 +10°.

EXAMPLE 34

Methyl 11 a;-cyclohexylamino-3a-hydroxy-5a-androstane-17/5-carboxylate 10 Diethyl azodicarboxylate (470 mg) was added to a mixture of triphenylphosphine (790 mg), formic 10

acid (0.11 ml) and Intermediate 32 (432 mg) in dryTHF (10 ml). The mixture was left for 20 h; brought to basic pH with 5% NaHC03 solution and extracted with ethyl acetate (x3). The extract was washed with water, dried and evaporated to leave a solid which was partially purified by preparative t.l.c. in CHCI3:MeOH (19:1) to give an oil. The oil was dissolved in ethyl acetate and the solution was extracted 15 with 2M—HCI solution (x3) and water (x3). The extract was brought to pH 10 with 0.88 NH3 solution 15 and the precipitate was extracted with ethyl acetate (x4). The extract was dried and evaporated to leave a foam which was purified by preparataive t.l.c. in CHCI3:MeOH (9:1) to give the title compound (67 mg) [a]0 +4°.

EXAMPLE 35

20 Methyl 11 a-cyclohexylamino-3a;-hydroxy-5a:-androstane-17/5-carboxylate 20

Chloroiridic acid reagent (16 ml) was brought to pH 7 with triethylamine and Intermediate 34 (860 mg) was dissolved in it. The solution was heated at reflux for 27 h, cooled and brought to pH 9 with 0.88 NH3 solution. Water (30 ml) was added and the mixture was extracted with ethyl acetate; (x3). The extract was washed with water, dried and evaporated to leave a foam which was purified by 25 preparative t.l.c. in CHCI3:MeOH (5:1) to give the title compound (248 mg) [a]Q +6°. 25

EXAMPLES 36—62

Table 7 summarises the preparation of the hydrochloride salts.

A solution of hydrochloric acid in water was added to the base or a suspension of the base in any additional water and the mixture was stirred or shaken until either a clear solution was obtained or no 30 more base dissolved. The mixture was made up to the appropriate weight or volume with water and 30 filtered and any undissolved base was collected, dried and weighed to determine the solution concentrations. The pH was measured.

TABLE 7

Example No.

Example No. of free base

Wt. (mg)

M

HCI

Vol. (ml)

- Additional Water (ml)

Total Weight or Volume

Solid residue (mg)

PH

Conc'n.

(%)

36

B1

300

0.0963

6.7

9

20 ml

—

2.7

1.5

37

B3

301

0.0963

6.6

9

20 ml

—

3.2

1.5

38

B13

100

0.0924

2.2

5

10 ml

—

3.2

1

39

B2

993

0.0979

21.8

-

125,03g

83

3.0

0.73

40

B9

674

0.0979

14.0

-

49.98g

40

3.2

1.27

41

B11

100.8

0.0979

2.23

-

10.03g

—

3.1

1.0

42

B17

100.6

0.0979

2.3

-

10.02g

-

3.7

1.0

43

B12

100

0.0979

2.4

-

10 ml

-

2.1

1.0

44

B16

100

0.0979

2.44

-

10 ml ■

-

3.0

1.0

45

B8

100

0.0979

2.34

-

10 ml

—

2.5

1.0

46

B26

100

0.0979

2.08

7

10 ml

—

2.95

1.0

47

B18

100

0.0979

2.14

5

10 ml

—

3.4

1.0

48

B19

100

0.0979

2.14

5

10 ml

—

3.4

1.0

49

B10

100

0.0979

2.44

6

10 ml

—

3.2

1.0

50

B4

284.3

0.0924

6.26

-

20.1g

135

2.3

0.76

51

B5

220.6

0.0924

4.72

—

20.04g

41

3.15

0.9

TABLE 7 (Continued)

Example HCI

Example No.

No. Of free base

Wt. (mg)

M

Vol. (ml)

- Additional Water (ml)

Total Weight or Volume

Solid residue (mg)

PH

Conc'n, (%)

52

B6

610.3

0.0924

12.7

-

40.01 g

339

2.5

0.68

53

B15

100

0.0924

2.28

6

10 rfil

—

3.05

1.0

54

B14

100

0.0924

2.27

6

10 ml

—

3.15

1.0

55

B7

100

0.0924

2.6

-

10 ml

-

2.75

1.0

56

B22

100

0.0979

2.09

-

10 g

—

4.0

1.0

57

B21

100.5

0.0979

2.15

-

10g

—

4.3

1.0

58

B20

100

0.0979

2.37

5

10 ml

—

3.0 .

1

59

B27

100

0.0979

1.92

15

20 ml

28

2.6

0.37

60

B23

101.2

0.1076

1.98

-

10 g

—

5.3

1.0

61

B24

100

0.1076

2.14

-

10 ml

10

2.2

0.9

62

B25

100.8

0.1076

2.15

-

10 g

2.4

1.0

26

GB 2 080 308 A

26

EXAMPLES 63—67

Table 8 summarises the preparation of salts of methyl 2/3-ethoxy-3a-hydroxy-11 a-(3-methylbutylamino)-5ar-androstane-17/3-carboxylate.

The appropriate acid was added to a suspension of the free base (50 mg) in water (4 ml) and the 5 mixture was stirred or shaken until a clear solution was obtained. The solution was made up to 5 ml 5

with water to give a 1 % solution and the pH was measured.

TABLE 8

Example No.

Acid

Vol or wt.

PH

63

Citric acid hydrate

22.7 mg

3.65

64

Maleic acid

12.5 mg

4.55

65

Ascorbic acid

37.98 mg

4.10

66

Sulphuric acid (0.1 M) 0.54 ml

2.90

67

Glutaric acid

14.2 mg

4.70

EXAMPLE 68

Methyl 11 a-cyclohexylamino-3a-hydroxy-2/5-methoxy-5a-androstane-17/3-carboxylate 10 Intermediate 12 was converted, by the general method described for the preparation of 10

Intermediate 32, into methyl 11 a-amino-5or-androst-2-ene-17/3-carboxylate, [a]D +57°, which was converted, by the general method described for the preparation of Intermediate 33, into methyl 11a-cyclohexylamino-5a-androst-2-ene-17/3-carboxylate, [a]D +18°.

This was converted, using the general method described for the preparation of Intermediate 2, into 15 methyl 11 a-(N-2,2,2-trichloroethoxycarbonyl)cyclohexylamin0-5a-androst-2-ene-17/3-carboxylate. 15

This was converted, by the general method described for the preparation of Intermediate 13, into methyl 2a,3a-epoxy-11 a-(N-2,2,2-trichloroethoxycarbonyl)cyclohexylamino-5a-androstane-17/5-carboxylate.

This was converted, by the general method described for the preparation of Intermediate 21, into 20 methyl 3a-hydroxy-2/3-methoxy-11a-(N-2,2,2-trichloroethoxycarbonyl)cyclohexylamino-5a- 20

androstane-17/5-carboxylate.

This compound (485 mg) in acetic acid (10 ml) was treated with zinc powder (1.0 g). After 89 h the zinc was removed by filtration and the filtrate was evaporated to dryness, diluted with dilute NH3 solution and extracted with ether (x3). The combined extracts were washed with water (x 1), dried and 25 evaporated to give a froth (321 mg) which was shown to contain the title compound by t.l.c. 25

(chloroform:methanol 9:1) and by comparison with the product of Example B11.

The following Examples illustrate pharmaceutical formulations of the compounds according to the invention.

30 EXAMPLE A 30

Tablet — wet Granulated mg/tablet

Methyl 11 a-cyclohexylamino-3a-hydroxy-2/3-methoxy-5a-androstane-17/5-carboxylate

35 hydrochloride 27.0 35

Lactose 93.0

Maize Starch 50.0

40

Polyvinyl pyrrolidone Sodium starch glycolate Magnesium stearate Tablet weight

2.0 6.0 2.0 180.0 mg

40

Sieve the steroid and maize starch through a 40 mesh screen. Blend the maize starch with the

27

GB 2 080 308 A 27

steroid in a suitable blender. Make a 5—10% w/v aqueous solution of the polyvinyl pyrrolidone. Add this solution to the mixing powder and mix until granulated. Pass the granulate through a number 12 screen. Dry the granules at 50°C in an oven or in a fluid bed dryer. Screen the dry granules through a 16 mesh screen, and blend in the sodium starch glycolate and magnesium stearate previously sieved through a 60 mesh screen. Compress on appropriate punches on an automatic tablet machine.'

EXAMPLE B

Tablet — Direct compression mg/tablet

Methyl 11 ar-cyclohexylamino-3or-hydroxy-

10 2/3-methoxy-5a-androstane-17/3-carboxylate 10

hydrochloride 27.0

Microcrystalline cellulose 135.0

Sodium starch glycolate 6.0

Magnesium stearate 2.0

15 170.0 mg 15

Sieve the steroid and microcrystalline cellulose through a 40 mesh sieve. Sieve the sodium starch glycolate and magnesium stearate through a 60 mesh sieve. Blend the powders together in a suitable blender until homogeneous. Compress on appropriate punches on an automatic tablet press.

The tablets, made in either Example A or B, may be covered in a thin polymer coat applied by the 20 usual film coating techniques. A.pigment may be included in the film coat. 20

EXAMPLE C Hard gelatin capsule

Methyl 2/3-ethoxy-3a-hydroxy-11 a-25 (3-methylbutylamino)-5ar-androstane-

mg/capsule

17/3-carboxylate hydrochloride 54.0

Lactose, anhydrous 141.0

Sodium starch glycolate 4.0

Magnesium stearate 1.0

25

30 Capsule fill weight 200.0 mg 3q

The steroid is sieved and blended by a gradual dilution technique with the sieved excipients, in a suitable blender. The blend is then filled into suitable size hard gelatin capsule shells using an automatic machine.

EXAMPLE D

35 Tablet — Wet granulated 35

mg/tablet

Methyl 2/3-ethoxy-3ct-hydroxy-11 a- 108.00 (3-methylbutylamino)-5a;-androstane-17/3-carboxylate hydrochloride

Maize starch 138.0 40

Polyvinyl pyrrolidone 2.5

Sodium starch glycolate 7.5

Magnesium stearate 2.0

40

Tablet weight

258.00

28

GB 2 080 308 A 28

The method of manufacture is as in Example A.

The tablets may be coated in a thin polymeric coat applied by the usual techniques. The film coat may contain a pigment.

EXAMPLE E

5 Intravenous Injections 5

Ingredients:

Methyl 11 a:-cyclohexylamino-3a:-hydroxy-2/3-methoxy-5a-androstane-17/3-carboxylate hydrochloride or methyl 2/3-eth oxy-3 a-h yd roxy-11 a:-(3-methylbutylamino)-5ar-androstane-17/3-carboxylate hydrochloride 10

(equivalent to 1 to 10 mg of free base)

Sodium chloride sufficient for isotonicity

Water for Injections to 1 ml

Dissolve the steroid and the sodium chloride in some of the water. If necessary adjust the pH with 15 sodium hydroxide solution or hydrochloric acid solution. Make up to volume with water and stir until 15 homogeneous. Filter the solution into clean glass vials and seal by fusion. The solution may be sterilised by autoclaving or filtration or preparing under aseptic conditions.

Claims (14)

CLAIMS'

1. Compounds of the formula:

R1HN

20 *1 S ' (l) 20

(wherein:

R1 is a C,_8 alkyl group or a C3_7 cycloalkyl group;

R2 is a hydrogen atom, a C,^ alkoxy group or a C2_s alkanoyloxy group; and

R3 is a C^g alkyl group or a C3_7 cycloalkyl group;

25 provided that when the compounds contain a 5/3-hydrogen atom, R2 is a hydrogen atom, and the 25 D-homo analogues thereof having the group —C02R3 (wherein R3 is as defined above) at the Composition, and acid addition salts thereof.

2. Compounds as claimed in claim 1 wherein:

R1 is an isopentyl, hexyl, isohexyl, neohexyl, cyclopentyl or cyclohexyl group, R2 is a hydrogen atom

30 or a methoxy, ethoxy or propoxy group and R3 is a methyl or ethyl group, having a 5a-hydrogen atom 30 and wherein ring D has 5 members.

3. Compounds as claimed in either of claims 1 and 2 in the form of physiologically acceptable acid addition salts.

4. Compounds as claimed in claim 3 in the form of hydrochlorides, hydrobromides, phosphates,

35 sulphates, p-toluenesulphonates, methanesulphonates, citrates, tartrates, acetates, ascorbates, 35

lactates, maleates, succinates, tricarballylates, glutarates and giutaconates.

5. A compound as claimed in claim 1 which is methyl 2/3-ethoxy-3a-hydroxy-11 a-(3-methylbutylamino)-5a-androstane-17/3-carboxylate, and its physiologically acceptable acid addition

* salts.

40

6. A compound as claimed in claim 1 which is methyl 2/3-methoxy-3ar-hydroxy-11 a-{3- 40

methylbutylamino)-5ar-androstane-17/3-carboxylate, and its physiologically acceptable acid addition salts.

7. A compound as claimed in claim 1 which is methyl 11 ar-cyclohexylamino-3ar-hydroxy-2/3-methoxy-5ar-androstane-17/3-carboxylate, and its physiologically acceptable acid addition salts.

45

8. A compound as claimed in claim 1 which is methyl 11 ar-cyclohexylamino-3a:-hydroxy-5a- 45

androstane-17/3-carboxylate, and its physiologically acceptable acid addition salts.

29

GB 2 080 308 A

29

10

15

20

25

9. Compounds as claimed in any of claims 5 to 8 in the form of their hydrochlorides.

10. Pharmaceutical compositions comprising at least one compound of formula (I) as claimed in claim 1 or a physiologically acceptable acid addition salt thereof in admixture with one or more pharmaceutical carriers or excipients.

11. A process for the manufacture of a compound of formula (I) as claimed in claim 1 including 5 reacting a corresponding 11 a;-amino compound or a corresponding 11 ar-amino-17/3-carboxylic acid with a compound of formula R'X wherein R1 is as defined in claim 1 and X is a readily displaceable atom or group;

(where a 2/3-substituted 5ct:-compound is desired) treating a corresponding 2ar,3a:-epoxide with a compound HR2 under acidic conditions or a compound which produces the anion (R2)- wherein R2 10 is as defined in claim 1 other then hydrogen, and then, when the initial product possesses a deprotonated 3ar-hydroxy group, treating the product obtained with a source of protons;

reacting a corresponding 11 a-amino compound in the presence of a reducing agent with a monocarbonyl compound serving to introduce the group R1;

(where a 2/3-unsubstituted compound is desired) reducing a corresponding 3-oxo compound; ,15 converting a corresponding N,N-disubstituted 11a-amino compound into an N-monosubstituted compound;

esterifying a corresponding 17/3-carboxylic acid;

reducing a corresponding A16-compound;

transesterifying a corresponding compound having a 17/3-ester group other than the desired group 20 R3 (as defined in claim 1) with an alcohol of formula R3OH (wherein R3 is as defined in claim 1). inverting a corresponding 3/3-hydroxy compound; or deprotecting a corresponding compound having a protected 3a-hydroxy group, followed where necessary, by the formation of acid addition salts.

12. Compounds of formula: 25

(A)

(B)

(C)

(D)

(E)

(F)

(G)

(H)

(I) (J)

CO„RJ

4

R HN „

(II)

(wherein R2 is as defined in claim 1 (provided that when the compunds contain a 5/3-hydrogen atom, R2 is a hydrogen atom);

R4 is a hydrogen atom or a group R1 as defined in claim 1; and 30 R5 is a hydrogen atom or a group R3 as defined in claim 1; 30

provided that at least one of R4 and Rs is a hydrogen atom and the D-homo analogues thereof having the group —COzR5 At the 17o;/3-position and salts and zwitterionic forms thereof.

13. A method of prophylaxis of a human or animal subject suffering from or liable to cardiac dysrhythmias which comprises administering to said subject an effective amount of one or more

35 compounds as claimed in any of claims 1 to 9. 35

14. Compounds as claimed in any of claims 1 to 9 for use in the therapy or prophylaxis of cardiac dysrhythmias in a human or animal subject.

Printed for Her Majesty's Stationery Office by the Courier Press, Leamington Spa. 1982. Published by the Patent Office. 25 Southampton Buildings, London, WC2A 1AY, from which copies may be obtained.'