GB2187459A

GB2187459A - 3-deoxo-10???-alkynyl steroids and process for their preparation

Info

Publication number: GB2187459A
Application number: GB08704842A
Authority: GB
Inventors: Franco Faustini; Vittoria Villa; Achille Panzeri; Salle Enrico Di
Original assignee: Farmitalia Carlo Erba SRL
Current assignee: Pfizer Italia SRL
Priority date: 1986-03-05
Filing date: 1987-03-02
Publication date: 1987-09-09
Also published as: DE3706647A1; GB8605405D0; IT1204911B; JPS62212398A; IT8719370A0; GB8704842D0

Abstract

3-Deoxo-10???-alkynyl steroids of formula (I> <IMAGE> wherein R is hydrogen, C1-C4 alkyl or halogen; n is 1 or 2; the symbol @ indicates that one of (a) and (b) is a double bond and the other is a single bond; one of R1 and R2 is hydrogen and the other is hydrogen, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl or halogen, or, when (b) is single bond and R2 is hydrogen, R1 may also be divalent and is C1-C6 alkylidene; are aromatase inhibitors and may be used in the treatment of estrogen-dependent diseases.

Description

SPECIFICATION 3-Deoxo-1 0ss-alkynyl steroids and process for their preparation The present invention relates to 3-deoxo-1 Oss-alkynyl steroids, to a process for their preparation and to pharmaceutical compositions containing them.

The invention provides compounds ofthefollowingformula (I)

wherein R is hydrogen, C1-C4 alkyl or halogen; nisi or2; the symbol indicates that one of (a) and (b) is a double bond and the other is a single bond; one of R1 and R2 is hydrogen and the other is hydrogen, C1-C6 alkyl, C2-C6 alkenyl, C2-C6alkynyl or halogen, or, when (b) is single bond and R2 is hydrogen, R1 may also be divalent and is C1-C6 alkylidene.

In the formulae ofthis specification a dotted line (IIIII) indicates a substituent in the a-configuration, i.e.

below the plane of the ring; a wedged line (#) indicates a substituent in the ss-configuration, i.e. above the plane of the ring, and a wavy line (#) indicates that a substituent may be in the a-configuration in the the ss-configuration or both. Consequently, where a formula has a substituent with a wavy line bond, the formula may represent a compound having the substituentsolely in the a-configuration our solely in the ss-configuration, or the formula may represent a mixture of both compounds having the substituent in the a-configuration and compounds having the substituent in the ss-configuration.

It is intended that the present invention includes all the possible isomers offormula (I), both separately and in mixture. In particular, for example, the invention is meantto include both the compounds offormula (I) wherein (a) is double bond and (b) is single bond and the isomeric compounds of formula (I) wherein (a) is single bond and (b) is double bond, both separately and in mixture, especially 1:1 mixture. In the present description a compound wherein (a) is double bond and (b) is single bond is also referred to as a 4-ene isomer, while a compound wherein (a) is single bond and (b) is double bond is also referred to as a 5-ene isomer.

In this specification the alkyl, alkenyl and alkynyl groups may be branched orstraight chain.

A C1-C4 or C1-C6 alkyl group is, preferably, methyl, ethyl, n-propyl or tert. butyl.

A C2-C6 alkenyl group is preferably a C2-C4 alkenyl, in particular, e.g., vinyl(CH2=CH-), allyl(CH2=CH-CH2), 1 -propenyl(CH3-CH =CH-), 1 -butenyl(CH3-CH2-CH=CH-), 2-butenyl(CH3-CH=CH-CH2-) or 3-butenyl(CH=CH- CH2-CH2-).

A C2-C6 alkynyl group is, preferably, C2-C4 alkynyl, in particular, e.g., ethynyl (CH=C-) or2-propynyl (CH=C- CH2-).

A halogen atom is, preferably, chlorine, bromine orfluorine.AC1-C6alkylidene is, preferably, C1-C4alkylidene, in particular, e.g., methylene (=CH2), ethylidene (=CH-CH3) or n-propylidene (=CH-CHrCH3).

When R is C1-C4 alkyl, methyl and ethyl are preferred, particularly methyl; when R is halogen, bromine and fluorine are preferred.

When one of R1 and R2 is C1 -C6 alkyl, methyl and ethyl are preferred, in particular methyl.

When one of R1 and R2 is C2-C6 alkenyl or C2-C6 alkynyl, vinyl and, respectively, ethynyl are preferred.

When one of R1 and Rip is halogen, this is, preferably, fluorine.

When R1 is C1-C6 alkylidene, this is, preferably, methylene.

Preferably in the above formula (I) R is hydrogen or halogen, in particular chlorine, bromine orfluorine; preferably one of R1 and R2 is hydrogen and the other is hydrogen, C1-C4 alkyl, in particular methyl, or halogen, in particularfluorine.

A preferred class of compounds underthis invention are the compounds offormula (I) wherein R is hydrogen or halogqn; nisi; the symbol indicates that one of (a) and (b) is double bond and the other is single bond; and R1 and F2 are both hydrogen or one of them is hydrogen and the other is C1-C4 alkyl or halogen.

In the above preferred class, when R is halogen, bromine, chlorine and fluorine are preferred; when one of R1 and R2 is C1-C4 alkyl, methyl is preferred; and when one of R1 and R2 is halogen,fluorine is preferred.

Examples of specific compounds underthis invention are: 10ss-(2-propynyl)estr-4-en-17-one; 10ss-(2-propynyl)estr-5-en-17-one; 1 OP-(2-propynyl)estr-4,5-en-1 7-one(1:1 mixture); 6a-methyl-1 Oss-(2-propynyl)estr-4-en-1 7-one; 6ss-methyl-10ss-(2-propynyl)estr-4-en-17-one; 7a-methyl-1 0ss-(2-propynyl )estr-4-en-1 7-one; 7ss-methyl-10ss-(2-propynyl)-estr-4-en-17-one; 6-methyl-10ss(2-propynyl)estr-5-en-17-one; 7c-methyl-1 Oss-(2-propynyl)estr-5-en-1 7-one; 7ss-methyl-10ss-(2-propynyl)estr-5-en-17-one; 10ss-(3-butynyl)estr-4-en-17-one; 10ss-(3-bromo-2-propynyl)estr-4-en-17-one; 10ss-(3-bromo-2-propynyl)estr-5-en-17-one; 10ss-(3-chloro-2-propynyl)estr-4-en-17-one;and 10ss-(3-chloro-2-propynyl)estr-5-en-17-one.

The compounds of the invention may be prepared by a process comprising: A) oxidizing a compound offormula (II)

wherein R1, R2, n and the symbol---- have the meanings reported above and R' is hydrogen or C1-C4 alkyl, to givethe corresponding 4-ene or 5-ene, or mixture thereof, of formula (I) wherein R is hydrogen or C1-C4 alkyl, or B) dehydrating a compound offormula (III)

wherein R', n, R1 and F2 are as defined above and Z is a free or protected oxo group, to give, when R1 is otherthan C1-C6 alkylidene, a mixture of 4-ene and 5-ene of formula (I) wherein R is hydrogen or C1-C4 alkyl or, when R1 is C1-C6alkylidene, a 4-ene offormula (wherein R is hydrogen or C1-C4alkyl, or C) selectively reducing a compound offormula (IV)

wherein R', R1, R2 and n are as defined above, A is a branched or straight chain C2-C6 alkenylene, and Y is a protected oxo group, and removing the protecting group from Y, to give a 4-ene offormula (I) wherein R is hydrogen or C1-C4 alkyl, or D) haloqenatinq a compound offormula (V) wherein

R1, R2, n and the symbol ---- have the meanings reported above, to give the corresponding 4-ene or 5-ene or mixture thereof of formula (I) wherein R is halogen; and, if desired, separating any mixture of isomers offormula (I) obtained intothe single isomers.

In accordance with the given definitions, the compound offormula (II) used as starting materialforthe oxidation step A) above, may be either a compound offormula (II)wherein (a) is double bond and (b) is single bond, i.e. a 4-ene compound, or a compound offormula (II)wherein (a) is single bond and (b) is double bond, i.e. a 5-ene compound, or a mixture of said 4-ene and 5-ene compounds.

The oxidation of a compound offormula (II) may be carried out by the use of known oxidizing agents, e.g.

with dicyclohexylcarbodiimide, pyridine and trifluoroacetic acid (the Moffatt's reagent) or with the Jones'or the Sarett's reagent.

When the starting material offormula (II) is a 4-ene compound, there is obtained a 4-ene compound of formula (I), when the starting material is a 5-ene compound it is obtained a 5-ene compound of formula (I) and,finally, when the starting material is a mixture of4-ene and 5-ene compounds offormula (11), it is ob- tained a corresponding mixture of and 5-ene compounds offormula (I).

When in a compound ofthe above formula (Ill) Z represents a protected oxo group, this may be,for example, an oxo group protected as acetal orthioacetal, e.g. dimethoxyacetal, diethoxyacetal, dimethylthioacetal ordiethylthioacetal, or as ketal orthioketal, e.g. ethylenedioxy-ketal or ethylenedithio-ketal.

The dehydration of a compound of formula (III) may be carried outwith a suitable dehydrating agentwhich may be, for example, thionylchloride, dicyclohexylcarbodiimide, or a mineral, preferably concentrated, acid, such as, for instance, hydrochloric or sulfuric acid, or with a sulfonic resin as well. The reaction may be performed in an inert, organic, preferably anhydrous, solvent, such as, for instance, methanol, ethanol, benzene,toluene, n-hexane or cyclohexane, at a temperature varying approximately between about 0 C and about 50 C, preferably at room temperature. When the reaction is carried out on a compound offormula (III), wherein Z is a protected oxo group, deprotection of the same proceeds simultaneously with dehydration.

When there is obtained a mixture of 4-ene and 5-ene-compounds of formula (I), the relative proportions of the two components may vary within broad ranges, particularly depending on the presence and on the nature of the R1 substituent. In most cases, however, 1:1 mixtures are obtained.

The protected oxo group Yin a compound offormula (IV) may be, e.g., an oxo group protected asacetal, e.g. dimethoxyacetal ordiethoxyacetal, or as ketal, e.g. ethylenedioxyketal. Preferably A in the compound of formula (IV) is a straight chain C2-C4 alkenylene, most preferably ethylene.

The selective reduction of a compound offormula (IV) may be performed by the known methods described in the organic chemistry for reduction ofthioketals; for instance, an alkali metal, such as, e.g., Li, Na or K, in liquid ammonia according to, e.g., the procedure reported by R.E. Ireland et al in J. Amer. Chem. Soc. 1-958, 80,4604, or Raney nickel according to, e.g., the procedure described by L.F. Fieser in J. Am. Chem. Soc. 70, 1945,1954, may be used.

The removal of the oxo protecting group from Yin the obtained compounds may be performed in a conventional manner, for instance by acid hydrolysis, e.g. with a mono- or poly-carboxylic acid such as, e.g., acetic, formic or oxalic acid, or with a sulfonic acid, such as, e.g., methanesulfonic orp-toiuenesulfonicor sulfuric acid, or with a sulfonic resin as well.

The halogenation of a compound offormula (V) may be performed by the known methods described in the organicchemistryforthis kind of reaction. Forexample,to obtain a compound offormula (I)wherein R is bromine or iodine, halogenation may be carried out with, e.g., an equimolar amount of N-bromo or N-iodosuccinimide in the presence of catalytic amounts of silver nitrate.

The halogenation reaction is generally performed in acetone, but other solvents such as e.g.,tetra- hydrofuran, ethanol or 1 -methyl-2-pyrrolidone can be used: R. Wiechert et al, Angew. Chem. Int. Ed. 23 (1984)9,727-728.

The optional separation of a mixture of isomers offormula (I) into the single isomers may be effected by known methods,forexample by fractional crystallization from an appropriate solvent or by chromatography, e.g. column or thin-layer chromatography or HPLC.

In particular, forexample, when the product obtained according to anyone of the process variants A), B) and D) described above is a mixture of compounds offormula (I) wherein (a) is double bond and (b) is single bond and of isomeric compounds of formula (I) wherein (a) is single bond and (b) is double bond, then, if desired, the said mixture may be separated into the single components by, e.g., the hereabove indicated techniques.

The new compounds offormula (II) may be prepared by dehydratig a compound offormula (VI):

wherein n, R', R1 and R2 are as defined above.

Dehydration may be, e.g., carried out following analogous procedure as that reported above forthe dehydration ofa compound offormula (III).

The reaction product may be a mixture of compounds offormula (Il) wherein (a) is double bond and (b) is single bond (i.e. estr-4-ene derivatives) and compounds of formula (III) wherein (a) is single bond and (b) is double bond (i.e. estr-5-ene derivatives).

In this case, if desired, the mixture may be separated by, e.g., chromatography or fractional crystallization.

An useful way for carrying outthe said separation, in order to obtain pure estr-4-ene derivatives and pure estr-5-ene derivatives of formula (III) wherein R' is hydrogen may be, for instance: (a) to halogenatethe mixture of estr-4-ene and estr-5-ene derivatives of formula (II) wherein R' is hydrogen possibly obtained from dehydration of compounds (Vl),so obtaining compounds offormula (Ila)

wherein n, R1, R2 and the symbol # have the meanings reported above and R" is halogen, as a mixture of 4-ene derivatives and 5-ene derivatives;; (b)to separate the obtained mixture of4-ene and 5-ene halo-compounds offormula (Ila) and (c) to de-halogenate a so obtained separated 4-ene or 5-ene-halo-derivative of formula (Ila).

The halogenation step (a) may be performed as previously reported for the halogeneration of a compound offormula (V). The separation step (b) may be carried out conventionally by, e.g., chromatography orfractional crystallization.

The de-halogenation step (c) may be carried out in a known manner, e.g. by means of hydrides or mixed hydrides such as, for instance, BH3, NaBH4, diisobutylaluminium hydride ortri-n-butyl-tin-hydride. When in the compound of formula (VI) R1 is a group C1-C6 alkylidene, the dehydration process leads exclusively to a corresponding 4-ene compound offormula (III). The new compounds offormula (III) may be obtained by reacting a compound of formula (VII):

wherein R1 and F2 are as defined above and Z' represents a protected oxo group, with a metallorganiccompound carrying a R'-CC-(CH2)n moiety wherein R' and n are as defined above, and, if desired, removing any oxo protecting group possibly still present.

The organometallic compound carrying a R'-CC-(CH2)n- moiety may be, for example, R'-CC-(CH2)n- MgX, wherein Xis a halogen atom, preferably chlorine, bromine or iodine, prepared according to known methods: L Brandsma and H.D. Verkruijsse, Synth. Acetylenes, Allenes and Cumulenes, 1981, 16. The reaction may be, e.g., carried out in a solvent chosen from tetrahydrofuran, tetrahydropyran, y-dihydropyran, diethylether and furan, e.g. at a temperature from about -30"Cto the room temperature, preferably between -5"Cand +10"C.

The subsequent removal of a possibly still present oxo protecting group may be, e.g., carried out by mild hydrolysis, e.g. mild acid hydrolysis, for instance with a diluted mineral, e.g. hydrochloric or sulfuric acid, or with a sulphonic resin, in a solvent which may be, for instance, acetone, an aliphatic, e.g. methyl or ethyl, alcohol, or an aromatic hydrocarbon, e.g. benzene ortoluene.

The compounds offormula (IV) are known or may be prepared by known methods from known compounds.

The compounds offormula (V) may be prepared, e.g., by the processes A), B) and C) reported aboveforthe preparation of compounds offormula (I).

Acompound offormula (VI) may be prepared reacting a compound offormula (VIII)

wherein R1 and R2 are as defined above, with a metallorganic compound carrying a R'-C#C-(CH2)n-moiety, wherein R' and n are as defined above.

The metallorganic compound carrying the R'-C#C-(CH2)n-moiety is like that previously indicated for the reaction with a compound offormula (VII), and its reaction on the compound (VIII) may be carried out in the same manner as on the compound (VII).

A compound with formula (VII) or (VIII) may be prepared epoxidizing a compound offormula (IX)

wherein R1 and R2 are as defined above, and either F3 and F4, taken together, form a protected oxo group [to prepare a compound with formula (VII)], or one of F3 and R4 is hydrogen and the other is free or protected hydroxy [to prepare a compound with formula (Vlil)].

When one of F3 and R4 is a protected hydroxy, it is, e.g., C2-C7 acyloxy, in particular acetoxy or benzoyloxy.

The epoxidation reaction may be performed according to known methods, for example as described by L. Nedelec in Bull. Soc. Chim. France 7,2548,1970.

Any hydroxy protecting group possibly present in the obtained compound may be removed conventionally.

Acompound offormula (IX) may be prepared by known methods, e.g. starting from a known compound of formula (X)

wherein R1, R2, R3 and R4are as defined above, and following, e.g.,the procedure described by M.S.W.Winter at al in Chem. Ind. 1959, 905.

The compounds of this invention possess a very high aromatase inhibiting activity.

Aromatase (estrogen synthetase) is the enzyme responsible for the final step in biosynthesis ofestrogens; as is known, the conversion of androgens to estrogens (e.g. ofandrostendione and testosterone to estrone and estradiol) is mediated by aroma, a microsomal P450 enzyme that acts on the androgenic substrate.

Numerous steroidic analogoues of natural substrates have been evaluated as aromatase inhibitors. In particular 10ss-propynyl steroids have been shown to inactivate aromatase with mechanism based inhibition (D.F. Covey et al, J. Biol. Chem. 1076,1981), and the same has been shown also for, e.g.,4-hydroxy androstendione (D.F. Covey W. F. Hood, Cancer Res. 42, 3327s, 1982).

A mechanism-based enzyme inhibitor is a relatively unreactive compound that bears a structural similarity to the substrate or product of the target enzyme which, via its normal mechanism of action, converts the inhibitor into another molecule that binds to the targetenzyme without prior release, and prevents enzyme catalysis from occurring.

By virtue of their ability to inhibit aromatase, the compounds offormula (I) are useful in the treatment of various estrogen dependent diseases, i.e., breast, endometrial, ovarian an pancreatic cancers, gynecom astia, benign breast disease, endometriosis and polycystic ovarian disease. Another application of the com- pounds ofthe invention is in the therapeutic and/or prophylactic treatment of prostatic hyperplasia, a disease of the estrogen dependent stromal tissue.

The aromatase inhibitors of formula (I) can find also use for the treatment of male infertility associated with oligospermia and for female fertility control, by virtue of their ability to inhibit ovulation and egg nidation.

The compounds of the invention can be administered in a variety of dosage forms, e.g. orally, in the form of tablets, capsules, sugar orfilm coated tablets, liquid solutions orsuspensions; rectally, in theform of sup- positories; parenterally, e.g. intramuscolarly, or by intravenous injection or infusion.

The dosage depends on the weight, conditions of the patient and administration route; for example the dosage adopted for oral administration to adult humans may range from about 10 to about 200 mg pro dose,from 1 to 5times daily.

The invention includes pharmaceutical compositions comprising a compound ofthe invention in association with a pharmaceutically acceptable excipient (which can be a carrierordiluent).

The pharmaceutical compositions containing the compounds of the invention are usually prepared follow- ing conventional methods and are administered in a pharmaceutically suitable form.

For example, the solid oral forms may contain, together with the active compound, diluents, e.g., lactose, dextrose, saccharose, cellulose, corn starch or potato starch; lubricants, e.g. silica, talc, stearic acid, magnesium our calcium stearate, and/or polyethylene glycols; binding agents, e.g. starches, arabic gums, gelatin, methylcellutose, carboxymethylcellulose or polyvinyl pyrrolidone; disaggregating agents, e.g. a starch, alginic acid, alginates or sodium starch glycolate; effervescing mixtures; dyestuffs; sweeteners; wetting agents, such as lecithin, polysorbates, lauryl-sulphates, and, in general, non-toxic and pharmacologically inactive substances used in pharmaceutical formulations.

Said pharmaceutical preparations may be manufactured in known manner, for example, by means of mixing, granulating, tabletting, sugar-coating, orfilm-coating processes. The liquid dispersions for oral administration may be e.g. syrups, emulsions and suspensions.

The syrups may contain as carrier, for example, saccharose orsaccharose with glycerine and/or mannitol and/orsorbitol; in particular in a syrup to be administered to diabetic patients can contain as carriers only products not metabolizableto glucose, or metabolizable in very small amount of glucose, for examplesor- bitol.

The suspensions and the emulsions may contain as carrier, for example, a natural gum, agar, sodium alginate, pectin, methycellulose, carboxymethylcellulose, or polyvinyl alcohol.

The suspensions orsolutions for intramuscolar injections may contain,togetherwith the active compound, a pharmaceutically acceptable carrier, e.g. sterile water, olive oil, ethyl oleate, glycols, e.g. propylene glycol, and is desired, a suitable amount of lidocaine hydrochloride. The solution for intravenous injections or infusions may contain as carrier, for example, sterile water or preferably they may be in the form of sterile, aqueous, isotonicsalinesolutions.

The suppositories may contain, together with the active compound, a pharmaceutically acceptable carrier, e.g. cocoa-butter, polyethylene glycol, a polyoxyethylene sorbitan fatty acid ester surfactant or lechithin.

In this specification the abbreviation THF and DMF stand, respectively, fortetrahydrofuran and di methylformamide. The following examples illustrate but do not limitthe invention.

Example 1 Into a solution of 17ss-hydroxy-estr-5(10)-en-3-one-17-acetate (10g) in 200 ml of acetic acid, 5 ml of ethanedithiol and 10 ml of BF3etherateare added cooling with external water bath at25 C.

The mixture is stirred at room temperature for 30 minutes then the slurry is diluted with 200 ml of water and filtered.

The solid is washed with water and dried at 50 C to yield 11.96 g of 17ss-hydroxy-estr-5(10)-en-3-one-3,3- ethylenedithioketal-1 7-acetate.

The obtainedthioketal is dissolved in 100 ml I ml ofdistilledTHFand dropped into a slurry of any nickel (40g) [prepared according to Org. Synth. 3,181] and the mixture is stirred for 1 hourat room temperature.

The nickel is filtered and washed with CH2Cl2 and the filtrate is evaporated in vacuum to yield a crudethat, after one recrysta 11 izatio n from methanol, gives 7.5 g of 1 7ss-hydroxy-estr-5(10)-en-17-acetate.

The compound is dissolved in 175 ml of 20% aqueous DMF, and 2.48g of CaC03 are added at once; 8.83 g of N-bromosuccinimide are added to the slurry and the mixture is stirred at room temperature for4 hours. The reaction mixture is quenched in 1000 ml of water and the crystals are filtered. The crude is dissolved in dichloromethane, washed with water, dried on Na2SO4 and the solvent is removed to yield a crude mixture of bromidrine and theformatethereof.

The crude is dissolved in 120 ml of dry methanol under nitrogen atmosphere and 7.2 g of sodium meth oxide are added portionwise under stirring at room temperature.

The reaction mixture is stirred for 3 hours then itis diluted with 1,000 ml of CH2Cl2, washed with water, dried over Na2SO4 and the solvent is removed in vacuum. The crude product is chromatographed on silica gel using n-hexane: ethyl acetate 80:20 as eluantto yield 5.58 g of pure 5,1 O-ol-epoxide-17P-hydroxy-estrane as white crystals, m.p. I 28-300C (uncorrected); [α]D=+82.3 (C=1,CHCl3).

Following analogous procedure and using as starting materials the appropriate estr-5(1 0)-en-3-one- derivatives, the below listed, 5,10-epoxides are prepared: 5,10-α-epoxide-6ss-methyl-17ss-hydroxy-estrane; 5,10-α-epoxide-6α-methyl-17ss-hydroxy-estrane; 5,10-α-epoxide-7ss-methyl-17ss-hydroxy-estrane; 5,10-α-epoxide-7α-methyl-17ss-hydroxy-estrane; 5,10-α-epoxide-6α-fluoro-17ss-hydroxy-estrane; 5,1 0-a-epoxide-6a-chloro-1 7'3-hydroxy-estrane.

Example 2 Under nitrogen atmosphere 1.14 g of 5,10-α-epoxide-17ss-hydroxy-estrane are dissolved in 20 ml of dry diethyl-ether; the solution is cooled to 0 C with external cooling bath and 35 ml of a 1.6 molar solution of propargyl magnesium bromide in diethyl ether [prepared according to the method reported in "Synthesis of Acetylenes, Allenes and Cumulenes", L. Brandsma and H.D. Verkruijsse, page 16, Elsevier Scientific Publish- ing Company-Amsterdam-Oxford-NewYork 1981] are added into the stirred solution.Stirring is continued4 hours and the temperature is maintained at O"C. Once the reaction is completed, 25 ml of saturated ammonium chloride solution are added always maintaining the temperature at 0 C; the mixture is then leftto rise to room temperature, 100 ml of water are added and the organic phase is separated.The aqueous layer is extracted sometimes with ethyl acetate; the organic phases are washed with water and evaporated to dry ness in vacuo to yield a crude which is purified by chromatography on silica gel using n-hexane:ethyl acetate 70:30 as eluantto yield 1.250 g of pure 5α,17ss-dihydroxy-10ss-(2-propynyl)-estrane as amorphous white solid halo = +27.7 (C=1, CHCI3); NMR (CDCl3)#:0.79 (3H,s,C18), 2.50 (2H,m,C19), 3.64(1 H,m,C12); IR (Nujol) cm-1: 3,400;3,300; 2,120.

Following analogous procedure,the below reported compounds are prepared: 6α-methyl-5α,17ss-dihydroxy-10ss-(2-propynyl)estrane; 6ss-methyl-5α,17ss-dihydroxy-10ss-(2-propynyl)estrane; 7α-methyl-5α,17ss-dihydroxy-10ss-(2-propynyl)estrane; 7ss-methyl-5α,17ss-dihydroxy-10ss-(2-propynyl)estrane; 60C-fluoro-50L,1 7ss-dihydroxy-1 Oss-(2-propynyl)estrane; 6α-chloro-5α,17ss-dihydroxy-10ss-(2-propynyl)estrane; 5α,17ss-dihydroxy-10ss-(3-butynyl)estrane.

Example 3 Into a solution of 10ss-(2-propynyl)-5α,17ss-dihydroxy-estrane (1.50 g) in 30 ml of acetone, cooled to -10 C with external cooling bath, 3 ml of a 2.5 molarJones reagent are dropped under stirring.

The solution is stirred 5 minutes then the excess reagent is destroyed by adding 0.5 ml of isopropyl alcohol.

The temperature is left to rise to 1 0"C; 100 ml of benzene are added and the solution is washed with saturated ammonium sulphate solution and water.

The organic phase is dried over Na2SO4, the solvent is removed in vacuo and the crude residue is purified on silica gel by flash chromatography using n-hexane:ethyl acetate 80:20 as eluant to yield 10ss-(2-propynyl) 5a-hydrnxy-estran-1 7-one (1.270 g) as white crystals, m.p. 1 74-76"C (uncorrected); NMR (CDCl3)#: 0.92 (3H,s,C18), 2.50 (2H,m,C19); IR (Nujol) cm-1:3,460;3,270; 1,730.

Example 4 A solution of 1.0 g of 10ss-(2-propynyl)-5α-hydroxy-estran-17-one in 200 ml of methanol is cooled to 0 C; 5 ml of pyridine are added and then 1.4 ml ofthionyl chloride are dropped slowly understirring.

The reaction mixture is stirred for 30 minutes then 20 ml of water are dropped with caution into the solution.

The mixture is extracted with ethyl acetate, washed with water, dried over Na2SO4 and the solvent is removed in vacuo to yield 0.85 g of a 1:1 mixture of 10ss-(2-propynyl)estr-4-en-17-one and 10ss-(2-propynyl) estr-5-en-1 7-one as a whitk amorphous solid which is referred to as 1 0ss-(2-propynyl)-estr-4,5-en-17-one, [α]D=+65.39 (C=1, CHCl3); [α]365=+463.2 (C=1,CHCl3); NMR (CDCl3)#:0.91-0.97 (3H,s,C18), 5.50 (1H,m,C4/C6); NMF (C13)8 : 31.8,35.8,52.5,54.5; IR (Nujol) cm-1: 3,250; 3,040; 1,730-1,740; 2,100; 1,680.

By analogous procedure the below listed compounds are prepared: 6a-methyl-1 Oss-(2-propynyl ) estr-4,5-en-1 7-one; 6ss-methyl-1 Oss-(2-propynyl) estr-4,5-en-17-one; 7α-methyl-10ss-(2-propynyl)estr-4,5-en-17-one; 10ss-(3-butynyl)estr-4,5-en-17-one; 6-methylene-10ss-(2-propynyl)estr-4-en-17-one; 6-methylene-1 Oss-(3-butynyl)estr-4-en-1 7-one; Example 5 A solution of unseparated 1:1 mixture of 10ss-(2-propynyl)estr-4-en-17-one and 10ss-(2-propynyl)estr-5-en17-one (1.2 g) in 30 ml of acetone is reacted at 25'Cwith 0.555 g of N-bromosuccinimide and 0.05 g silver nitrate.

After 60 minutes the reaction mixture is poured into ice-water and stirred for 30 minuted. The mixture is extracted with ethyl acetate, the organic phase is washed with water, dried over Na2SO4 and the solvent is removed at reduced pressure. The crude mixture is purified by chromatography on silica gel using nhexane: diethyl ether 80:20 as eluantto yield 10ss-(3-bromo-2-propynyl) estr-5-en-1 7-one (0.506 g) as the less polar (fast moving)isomer, [α]D=-20.87 ,[α]365=+100.6 (C=1,CHCl3); and 10ss-(3-bromo-2-propynyl)estr-4en-17-one (0.510 g) as the more polar (less moving) isomer, [a]D=+100.0 , [a]365=+539.1' (C=1, CHC3).

Following analogous procedure and using the appropriate halogenating agentthe below listed compounds are prepared: 10ss-(3-iodo-2-propynyl)estr-5-en-17-one; 10ss-(3-iodo-2-propynyl)estr-4-en-17-one; 10ss-(3-chloro-2-propynyl)estr-5-en-17-one; 10ss-(3-chloro-2-propynyl)estr-4-en-17-one; 6a-methyl-1 Oss-(3-bromo-2-propynyl )estr-5-en-1 7-one; Ga-methyl-l OP-(3-bromo-2-propynyl)estr-4-en-l 7-one; 6α-methyl-10ss-(3-iodo-2-propynyl)estr-5-en-17-one; 6a-methyl-1 Oss-(3-iodo-2-propynyl)estr-4-en-1 7-one; 6α-methyl-10ss-(3-chloro-2-propynyl)estr-5-en-17-one; 6α-methyl-10ss-(3-chloro-2-propynyl)estr-4-en-17-one; 6ss-methyl-10ss-(3-bromo-2-propynyl)estr-5-en-17-one; 6ss-methyl-10ss-(3-bromo-2-propynyl)estr-4-en-17-one; 7a-methyl-1 Oss-(3-chloro-2-propynyl )estr-4-en-1 7-one;; 7et-methyl-10ss-(3-bromo-2-propynyl)estr-4-en-17-one; 7a-methyl-10ss-(3-iodo-2-propynyl)estr-4-en-17-one.

Example 6 Into a slurry of 0.200 g of NaNH2 in 40 ml of dry NH3 cooled to -40'Cwith external cooling bath, is dropped a solution of 17ss-hydroxy-10ss-(2-propynyl)estr-4-en-3-one-3,3-ethylene-dithioetal (1.17 g) in 15 ml of dry diethyl ether.

The mixture is stirred at -400Cfor40 minutes then 0.300 g of metallic Na are added in small pieces and the solution is stirred forfu rther 30 minutes.

Into the bleu coloured solution 1.3 g of NH4CI are added and the reaction mixture is discoloured.The ammonia is evaporated and the crude residue is kept in 100 ml of a 1:1 mixture of diethyl ether and water; the mixture is extracted with ethyl acetate, the organic phase is dried and the solvent is removed to give 1.2 g of crude product. The chromatographic purification on silica gel using n-hexane;diethyl ether 70:30 as eluant yields 0.785 g of pure 17P-hydroxy-10P-(2-propynyl)estr-4-ene as colourless oil, IR (Nujoi) cm-1: 3,310; 2,110.

Example 7 A 2.5 molar solution of Jones reagent (1.5 ml) is dropped into a stirred solution containing 0.785 g of 17ss-hydroxy-10ss-(2-propynyl)estr-4-ene in 40 ml of acetone, cooled to -20 C. The reddish solution turnsto green colourand after5 minutesthe reaction is completed.

3 ml of isopropanol are dropped into the solution, then it is diluted with 100 ml of benzene and 10 ml of saturated aqueous ammonium sulfate solution. The organic phase is separated, washed with water, dried and the solvent is removed to give 0.800 g of crude product which, after chromatographic purification on silica gel using n-hexane:diethyl ether 85:15 as eluant, yields 0.582 g of pure 10ss-(2-propynyl)estr-4-en-17-one, m.p. 105-107 C; [α]D=+168 , [α]365=+841 (C=1, CHC13); IR (Nujol) cm-1: 3,260; 1,730; 1,660.

Following analogous procedure the below listed compounds are prepared: 6α-methyl-10ss-(2-propynyl)estr-4-en-17-one; 6ss-methyl-1 Oss-(2-propynyl Xestr-4-en-1 7-one; 7a-methyl-1 Op-(2-propynyl)estr-4-en-1 7-one; 7ss-methyl-1 Oss-(2-propynyl)estr-4-en-1 7-one; 6a-chloro-1 Oss-(2-propynyl)estr-4-en-1 7-one; 6a-fluoro-1 Oss-(2-propynyl)estr-4-en-1 7-one; 10ss-(3-butynyl)estr-4-en-17-one.

Example 8 Into a solution of 2.6 g of 1 Oss-(2-propynyl)ester-4-en-3,1 7-dione-3,3-ethylendithio-17,17- ethyienedioxyketal in 20 ml of dry diethyl ether are added 60 ml of liquid NH3.

The solution is maintained at -40 C with external cooling bath and 0.6 g of sodium metal are added in small pieces.

The deep bleu coloured solution is stirred for 20 minutes at -40 C then 2.5 g of NH4CI are added portionwise and the reaction mixture is discoloured. The cooling bath is removed and the ammonia is evaporated to yield an oily residue which is kept in 100 ml of diethyl ether and 50 ml of water; the mixture is extracted with ethyl acetate and the organic phase is washed with water and dried over sodium sulphate.

The solvent is removed to give 1.8 g of crude oily product which is dissolved in 30 ml of methanol and 4 ml of 5N HCI and then stirred at room temperature for 5 hours.

The reaction mixture is quenched into 400 ml of ice and water, neutralized with 1 N NaOH and extracted with ethyl acetate. The organic phase is washed with water and dried over Na2SO4, then the solvent is removed at reduced pressure and the crude product is purified by liquid chromatography on silica gel using cyclohexane:diethyl ether 80:20 as eluantto yield 1.2 g of pure 10P-(2-propynyl)estr-4-en-17-one, m.p. 106- 107 C.

Example 9 Into a stirred solution of 17p-hydroxy-l OP-(3-bromo-2-propynyl)estr-4-ene (0.190 g) in 3 ml of toluene, 0.3 ml oftri-n-butyltinhydride are dropped under nitrogen atmosphere. The mixture is warmed and kept at 70 C under stirring for 1 hour, then it is diluted with 5 ml oftoluene, washed with Seignette salt saturated solution and dried; the solvent is removed in vacuo to give 0.140 g of crude product.

The chromatographic purification of the crude on silica gel, using n-hexane:diethyl ether 70:30 as eluant, yields 0.125 g of pure 17ss-hydroxy-10ss-(2-propynyl)estr-4-ene as colourless oil, IR (Nujol):cm-1:3,310; 2,110.

By analogous procedure, starting from 17ss-hydroxy-(3-bromo-2-propynyl)estr-5-ene, the 1 7ss-hydroxy-(2- propynyl)estr-5-ene is obtained.

Following the procedure reported in example 7 the above compounds are oxidized to the corresponding 10ss-(2-propynyl)estr-4-en-one, m.p. 105-7 C, [α]D=+168 (C=1,CHCl3), and 10ss-(2-propynyl)estr-5-en-17one, [Ot]D =-37 C (C=1, CHCI3).

In analogous fashion alsothecompounds 6-methyl-1 Oss-(2-propynyl)estr-5-en-1 7-one; 7α-methyl-10ss-(2-propynyl)estr-5-en-17-one; and 7ss-methyl-10ss-(2-propynyl)estr-5-en-17-one are obtained.

Example 10 Tablets each weighing 0.150 g and containing 25 g of the active substance, are manfactured as follows: Composition (for 10,000tablets) 10ss-(2-propynyl)estr-4-en-17-one 250 g Lactose 800g Corn starch 415 g Talc powder 30g Magnesium stearate 5 g The 10ss-(2-propynyl)estr-4-en-17-one, the lactose and half the corn starch are mixed; the mixture isthen forced through a sieve of 0.5 mm size. Corn starch (10 g) is suspended in warm water (90 ml) and the resulting paste is used to granulate the powder.

The granulate is dried, comminuted on a sieve of 1.4 mm mesh size, then the remaining quantity of starch, tale and magnesium stearate is added, carefully mixed and processed into tablets.

Example 11 Capsules, each dosed at 0.200 g and containing 40 mg of the active substance are prepared.

Composition for 10,000 capsules: 10P-(2-propynyl)estr-4,5-en-17-one 400 9 Lactose 1,400g Corn starch 100g Magnesium stearate 100 9 This formulation is encapsulated in two-piece hard gelatin capsules and dosed at 0.200 g for each capsule.

Claims

1. Acompoundofformula (I)

wherein R is hydrogen, C1-C4 alkyl or halogen; nis 1 or 2; the symbol ---- in dicates that one of (a) and (b) is a double bond and the other is a single bond; one of R1 and R2 is hydrogen and the other is hydrogen, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl or halogen, or, when (b) is single bond and R2 is hydrogen, R1 may also be divalent and is C1-C6alkylidene.

2. Acompound offormula (I) according to claim 1 wherein R is hydrogen or halogen; nisl; the symbol---- indicates that one of (a) and (b) is double bond and the other is single bond; and R1 and F2 are both hydrogen or one ofthem is hydrogen and the other is C1-C4alkyI or halogen.

3. A compound selected from the group consisting of: 10ss-(2-propynyl)estr-4-en-17-one; 10ss-(2-propynyl)estr-5-en-17-one; 10ss-(2-propynyl)estr-4,5-en-17-one(1:1 mixture); 6α-methyl-10ss-(2-propynyl)estr-4-en-17-one; 6ss-methyl-10ss-(2-propynyl)estr-4-en-17-one; 7a-methyl-1 Op-(2-propynyl)estr-4-en-1 7-one; 7ss-methyl-10ss-(2-propynyl)-estr-4-en-17-one; 6-methyl-10ss-(2-propynyl)estr-5-en-17-one; 7α-methyl-10ss-(2-propynyl)estr-5-en-17-one; 7ss-methyl-1 Op-(2-propynyl)estr-5-en-1 7-one; 10ss-(3-butynyl)estr-4-en-17-one; 10ss-(3-bromo-2-propynyl)estr-4-en-17-one; 1 Oss-(3-bromo-2-propynyl )estr-5-en-1 7-one; 10ss-(3-chloro-2-propynyl)estr-4-en-17-one; and 10ss-(3-chloro-2-propynyl)estr-5-en-17-one.

4. A process for the preparation of a compound offormula (I) according to claim 1,the process comprising: A) oxidizing a compound offormula (II)

wherein R1, R2, n and the symbol ---- are as defined in claim 1 and R' is hydrogen or C1-C4 alkyl to give the corresponding 4-ene or 5-ene or mixture thereof of formula (I) wherein R is hydrogen or C1-C4 alkyl, or B) dehydrating a compound offormula (III)

wherein R', n, R1 and F2 are as defined above and Z is a free or protected oxo group, to give, when R1 is otherthan C1-C6 alkylidene, a mixture of 4-ene and 5-ene of formula (I) wherein R is hydrogen or C1-C4 alkyl or, when R1 is C1-C6 alkylidene, a 4-ene offormula (I) wherein R is hydrogen or C1-C4 alkyl, or C) selectively reducing a compound offormula (IV)

wherein R', R1, R2 and n are as defined above; A is a branched or straight chain C2-C6 alkenylene, and Y is a protected oxo group, and removing the protecting group from Y, to give a 4-ene of formula (I) wherein R is hydrogen orC1-C4alkyl, or D) halogenating a compound offormula (V)

wherein R1, R2, n and the symbol---- are as defined in claim 1,to give the corresponding 4-ene or5-ene ormixture thereof of formula (I) wherein R is halogen; and, if desired, separating any mixture of isomers offormula (I) obtained into the single isomers.

5. A processforthe preparation of a compound offormula (I) as defined in claim 1, said process being substantially as hereinbefore described in any one of Examples 4to 9.

6. A pharmaceutical composition containing a pharmaceutically acceptable carrier and/or diluent and, as the active substance, a compound of formula (I) according to any one of claims 1 to 3.

7. A pharmaceutical composition substantially as hereinbefore described in Example 10 or 11.

8. Acompound according to anyone of claims 1 to 3ora composition according to claim 6 or7for use in a method of treatment of the human or animal body bysurgeryortherapyor in a method of diagnosis on the human or animal body.

9. Acompound or composition according to claim 8foruse in aromatase inhibitor.

10. A compound or composition according to claim 9 for use in the treatment of an estrogen-dependent disease.

11. A compound or composition according to claim 8 for use in treatment of male infertility associated with oligospermia.

12. A compound of composition according to claim 8 for use in femalefertility control.

13. Acompound offormula (I), as defined in claim 1, hereinbeforespecified otherthan acompound claimed in claim 3.

14. Acompound ofthegeneralformula

wherein R, R2, n, (a) and (b) are as defined in claim 1 and R' is as defined in claim 4.

15. Acompoundofthegeneralformula

wherein R1, R2 and n are as defined in claim 1, Z is a free or protected oxo group, and R' is as defined in claim 4.