SE505213C2 - Dideoxycarbocyclic nucleoside analogues, pharmaceutical preparations thereof and intermediates - Google Patents

Abstract

Disclosed are compounds of formula (see fig. I) wherein X is H, NRR1, SR, OR or halogen; Z is H, OR2 or NRR1; R,R1,R2 are H, C1-4alkyl or aryl and pharmaceutically acceptable derivatives thereof. Also disclosed are use of the compounds as antiviral and anti-tumor agents, pharmaceutical formulations, methods for the preparation of the compounds and intermediates thereto.

Description

¿V _. 505 ziz 2 zidovudine has serious side effects and causes suppression of bone marrow, leading to a decrease in the number of white blood cells resulting in pronounced anemia and therefore there is a need for effective agents that are less cytotoxic.

We have now found a new class of nucleoside analogues with antiviral activity. Accordingly, in a first aspect, there is provided a compound of formula (I) X I N O I \ / O t? In which X is hydrogen, NRR 1, SR, OR or halogen; Z is hydrogen, Z 1 H 2 -CH 2 O \ \. (\. \ / .__, _. 0 wherein X is hydrogen, NRR 1, SR, OR or halogen; OR 2 or NR 1 R 1, R 1, R 1 and R 2 may be the same or different and are selected from hydrogen, C 1-4 alkyl and aryl, and pharmaceutically acceptable derivatives thereof.

One skilled in the art will recognize that the compounds of formula (I) are cis compounds and further that the cyclopentene ring of the compounds of formula (I) contains two chiral centers (shown in formula (I) by *) and may thus exist in the form of two optical isomers (ie enantiomers) and mixtures thereof comprising racemic mixtures. All such isomers and mixtures thereof including racemic mixtures are included within the scope of the invention. Thus, in the compounds of formula (I), either the chiral center to which the base is attached is in the R-configuration and the chiral center to which the CH 2 OH group is attached is in the S-configuration (hereinafter the D-isomer) or the chiral center to which the base attached is in the S-configuration and the one to which the CHZOH group is attached is in the f-3 asus 215 R-configuration (hereinafter the L-isomer). Suitably the compounds are in the form of either a racemic mixture or substantially the pure D-isomer. The D-isomers can be illustrated by the formula (Ia) É N rï fl \ ï / \\ Z / ° \\ N / \ N / rio-w \ / .__- 0 _._ 0 (Ia) wherein X and Z have it in the formula (I) specified definition. The reference below to compounds of formula (I) includes compounds of formula (Ia).

It will also be appreciated by one skilled in the art that some of the compounds of formula (I) may exist as a number of tautomeric forms and all such tautomers are included within the scope of the invention.

As used in this context, the term "halogen" refers to fluorine, chlorine, bromine and iodine; when X is halogen it is preferably chlorine.

As used herein, "C 1-4 alkyl" denotes a straight or branched alkyl chain, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl and t-butyl. Preferably C 1-4 alkyl is methyl.

The term "aryl" as used herein refers to any mono- or polycyclic aromatic group and includes unsubstituted and substituted aryl (such as phenyl, tolyl, xylyl, anisyl) and unsubstituted and substituted aralkyl including (C 1-4) alkyl, such as phen (C1-4) alkyl, for example benzyl. * v'-f | .. 505 213 4 or phenethyl.

In the compounds of formula (I), Z is preferably amino.

In a preferred class of compounds of formula (I), X is OR, especially OH.

According to a further preferred class of compounds of formula (I) X is NRR 1, especially NH 2 or hydrogen.

Particularly preferred compounds of formula (I) are those wherein Z is NH 2 and X is H, NH 2 or, especially, OH. In particular, such compounds have particularly desirable therapeutic properties as antiviral agents.

By "a pharmaceutically acceptable derivative" is meant all pharmaceutically acceptable salts, esters, or salts of such esters, of compounds of formula (I) or any other compound which upon administration to the recipient is capable of giving (directly or indirectly) a compound of formula (I) or an antivirally active metabolite or residue thereof.

Preferred esters of the compounds of formula (I) include carboxylic acid esters, wherein the non-carbonyl moiety of the ester group is selected from hydrogen, straight or branched chain alkyl (eg methyl, ethyl, n-propyl, t-butyl, n-butyl), alkoxyalkyl ( eg methoxymethyl), aralkyl (eg benzyl), aryloxyalkyl (eg phenoxymethyl), aryl (eg phenyl optionally substituted with halogen, alkyl or C 1-4 alkoxy); sulfonate esters such as alkyl-C 1-4 1-4 or aralkylsulfonyl (eg methanesulfonyl); amino acid esters (eg L-valyl or L-isoleucyl) and mono-, di- or triphosphate esters.

In view of the esters described above, unless otherwise indicated, any of the alkyl groups present preferably contain 1 to 18 carbon atoms, especially 1 to 4 carbon atoms. All aryl groups present in such esters preferably include a phenyl group.

Pharmaceutically acceptable salts of the compounds of formula (I) include those derived from pharmaceutically acceptable inorganic and organic acids and bases. Examples of suitable acids include hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, perchloric acid, fumaric acid, maleic acid, phosphoric acid, glycolic acid, lactic acid, salicylic acid, succinic acid, toluene-p-sulfonic acid, tartaric acid, acetic acid, citric acid, malonic acid, nanoic acid -2-sulfonic acid and benzenesulfonic acid. Other acids such as oxalic acid, although not themselves pharmaceutically acceptable, may be used in the preparation of salts useful as intermediates in the preparation of the compounds of the invention and their pharmaceutically acceptable acid addition salts.

Salts derived from appropriate bases include alkali metal (eg sodium), alkaline earth metal (eg magnesium), ammonium and NR 4+ (wherein R is C 1-4 alkyl) salts.

References herein to a compound of the invention include both compounds of formula (I) and their pharmaceutically acceptable derivatives.

Specific compounds of formula (I) include: (1w, 4%) - 4- (6-chloro-9H-purin-9-yl) -2-cyclopentenyl-carbinol; (1α, 4N) -4- (6-hydroxy-9H-purin-9-yl) -2-cyclopentenyl-carbinol; (lu, 4u) -4- (6-amino-9H-purin-9-yl) -2-cyclopentenyl-carbinol; (1,4G) -4- (6-mercapto-9H-purin-9-yl) -2-cyclopentenyl-carbinol; (1α, 4G) -4- (2-amino-6-chloro-9H-purin-9-yl) -2-cyclopentenyl-carbinol; (1m, 4q) -4- (2-amino-6-hydroxy-9H-purin-9-yl) -2-cyclopentenyl-carbinol, (1a, .4a) -4- (2,6-diamino-9H- purin-9-yl) -2-cyclopentenyl-carbinol; in the form of a racemic mixture or a simple enantiomer.

The compounds of the invention either possess in themselves antiviral activity and / or are metabolizable to such compounds. In particular, these compounds are effective in inhibiting retroviral replication of human retroviruses such as human immunodeficiency virus (HIV), the causative agent of AIDS.

Certain compounds of the invention, especially those wherein Z is H, also have anticancer activity.

Thus, according to a further aspect of the invention there is provided a compound of formula (I) or a pharmaceutically acceptable derivative thereof, for use as an active therapeutic agent, especially as an antiviral agent, for example in the treatment of retroviral infections, or as an anticancer agent.

In a further or alternative aspect, there is provided a method of treating a viral infection, in particular an infection caused by a retrovirus, such as HIV, in a mammal comprising a human, which comprises administering an effective amount of an antiviral compound of formula (I) or a pharmaceutically acceptable derivative thereof.

Thus, in a further or alternative aspect, there is provided the use of a compound of formula (I) or a pharmaceutically acceptable derivative thereof for the manufacture of a medicament for the treatment of a viral infection or for use as an anticancer agent.

The compounds of the invention having antiviral activity are also useful for the treatment of AIDS-related conditions, such as AIDS-related complex (ARC), progressive generalized lymphadenopathy (PGL), AIDS-related neurological conditions (such as dementia or tropical paraparesis), anti-HIV antibody-positive and HIV-positive conditions, Kaposi's sarcoma and thrombocytopenia purpura.

The antiviral compounds of the invention are also useful for preventing the progression of clinical disease in individuals who are anti-HIV antibody or HIV antigen-positive and for prophylaxis after exposure to HIV.

The antiviral compounds of formula (I) or the pharmaceutically acceptable derivatives thereof may also be used to prevent viral contamination of physiological fluids, such as blood or semen in vitro.

Some of the compounds of formula (I) are also useful as intermediates in the preparation of other compounds of the invention.

It will be appreciated by one skilled in the art that reference herein to treatment includes prophylaxis as well as treatment of established infections or symptoms.

It will be further appreciated by one skilled in the art that the amount of a compound of the invention required for use in treatment will vary not only with the particular compound selected but also with the mode of administration, the nature of the condition to be treated and the age and condition of the patient. the responsible doctor or veterinarian. In general, however, a suitable dose is in a range of from about 1 to 750 mg / kg, e.g. from about 10 to about 750 mg / kg body weight per day, such as 3 to about 120 mg / kg body weight of the recipient per day, preferably in the range of from 6 to 90 mg / kg / day, most preferably in the range of 15 to 60 mg / kg / day.

The desired dose may conveniently be provided as a single dose or as divided doses administered at appropriate intervals, for example as two, three, four or more sub-doses per day.

The compound is conveniently administered in unit dosage form; for example containing 10 to 1500 mg, preferably 20 to 1000 mg, most preferably 50 to 700 mg of the active ingredient per unit dosage form.

.Ilfyí 'u -, - | 1nw 505 zís 8 Preferably, the active ingredient should be administered to achieve peak plasma concentrations of the active compound of from about 1 to about 75 μM, preferably about 2 to 50 μM, most preferably about 3 to about 30 μM. This can be accomplished, for example, by intravenous injection of a 0.1 to 1% solution of the active ingredient, optionally in brine, or by oral administration as a bolus containing about 1 to about 100 mg of the active ingredient.

Appropriate blood levels may be maintained by continuous infusion to provide about 0.01 to about 5.0 mg / kg / hour or by intermittent infusions containing about 0.4 to about 15 mg / kg of the active ingredient.

Although it is possible for use in therapy that a compound of the invention be administered as a raw material, it is preferred to provide the active ingredient as a pharmaceutical formulation.

The invention thus provides a further pharmaceutical formulation comprising a compound of formula (I) or a pharmaceutically acceptable derivative thereof, together with one or more pharmaceutically acceptable carriers thereof and, optionally, other therapeutic and / or prophylactic ingredients. The carrier (s) must be "acceptable" in the sense of being compatible with other ingredients of the formulation and not deleterious to the recipient thereof.

Pharmaceutical formulations include those suitable for oral, rectal, nasal, topical (including buccal and sub-lingual), vaginal or parenteral (including intramuscular, subcutaneous and intravenous) administration or in a form suitable for administration by inhalation or insufflation.

The formulations may, when appropriate, be conveniently provided in separate dosage units and may be prepared according to any of the methods well known in the art of pharmacy. All methods include the step of bringing into association the active compound with liquid carriers or finely divided solid carriers or both, and then, if necessary, pro-. u 9 .5Û5 213 the product is formed into the desired formulation.

Pharmaceutical formulations suitable for oral administration may conveniently be provided as separate units such as capsules, cachets or tablets, each containing a predetermined amount of the active ingredient; such as a powder or granules; as a solution, a suspension or as an emulsion. The active ingredient may also be provided as a boli, electuary or paste. Tablets and capsules for oral administration may contain conventional excipients such as binders, fillers, lubricants, disintegrants or wetting agents. The tablets may be coated according to methods well known in the art. Other liquid preparations may be, for example, in the form of aqueous or oleaginous suspensions, solutions, emulsions, syrups or elixirs, or may be provided as a dry product for reconstitution with water or other suitable vehicle before use.

Such liquid preparations may contain conventional additives, such as suspending agents, emulsifying agents, non-aqueous vehicles (which may include edible oils) or preservatives.

The compounds of the invention may also be formulated for parenteral administration (eg by injection, for example bolus injection or continuous infusion) and may be supplied in unit dosage form in ampoules, pre-filled syringes, small volume infusion or in multidose containers containing one or more - set preservatives. The compositions may take such forms as suspensions, solutions or emulsions in an oily or aqueous vehicle and may contain formulatory agents such as suspending, stabilizing and / or dispersing agents. Alternatively, the active ingredient may be in powder form obtained by aseptic isolation of a sterile solid or by lyophilization from solution, for reconstitution with a suitable vehicle, e.g. sterile, pyrogen-free water, before use.

For topical administration to the epidermis, the compounds f * 1. 505 213 .L | '«_? | -.- l-" according to the invention are formulated as ointments, creams or lotions, or as a transdermal patch. Ointments and creams may, for example, be formulated with an aqueous or oily base with lotions can be formulated with an aqueous or oily base and also generally contain one or more emulsifying agents, stabilizing agents, dispersing agents, suspending agents, thickening agents or coloring agents.

Formulations suitable for topical administration in the mouth include lozenges comprising the active ingredient in a flavored base, generally sucrose and acacia or dragant; lozenges comprising the active ingredient in an inert base such as gelatin and glycerin or sucrose and acacia; and mouthwash comprising the active ingredient in a suitable liquid carrier.

Pharmaceutical formulations suitable for rectal administration in which the carrier is a solid are most preferably provided as unit dose suppositories. Suitable carriers include cocoa butter and other materials commonly used in the art, and suppositories may conveniently be formed by mixing the active compound with soft or molten carriers followed by cooling and molding.

Formulations suitable for vaginal administration may be provided as pessaries, tampons, creams, gels, pastes, foams or sprays containing, in addition to the active ingredient, carriers which are known to be useful in the art.

For intranasal administration, the compounds of the invention may be used as a liquid spray or in the form of drops.

Drops may be formulated with an aqueous or non-aqueous base which also includes one or more other dispersing agents, solubilizing agents or suspending agents.

Liquid sprays are conveniently provided from compressed air packs.

For administration by inhalation, the compounds of the invention are suitably provided from an insufflator, nebulizer or compressed air package or other suitable device for the provision of an aerosol spray.

Compressed air packages may include a suitable propellant such as dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, carbon dioxide or any other suitable gas. In the case of compressed air-packed aerosol, the dosage unit can be determined by providing a valve which delivers a measured amount.

Alternatively, for administration by inhalation or suffocation, the compounds of the invention may be in the form of a dry powder composition, for example a powder mixture of the compounds and a suitable powder base, such as lactose or starch. The powder composition can be provided as a unit dosage form in, for example, capsules or cartridges, or e.g. gelatin or patch packs from which the powder is administered by means of an inhaler or insufflator.

When desired, the formulations described above can be used adapted to provide continuous release of the active ingredient.

The pharmaceutical compositions of the invention may also contain other active ingredients such as antimicrobials or preservatives.

The compounds of the invention may also be used in combination with other therapeutic agents, such as, for example, other anti-infective agents. In particular, the compounds of the invention may be used in conjunction with known antiviral agents.

Thus, in a further aspect, the invention provides a combination comprising a compound of formula (I) or a physiologically acceptable derivative thereof, together with another therapeutically active agent, in particular an anti-'M, 4, »| -_'..- r 505 213 12 viral agent.

The above combinations may conveniently be provided for use in the form of a pharmaceutical formulation and thus pharmaceutical formulations comprising a combination as defined above together with a pharmaceutically acceptable carrier thereof, constitute a further aspect of the invention.

Suitable therapeutic agents for use in such combinations include acyclic nucleosides such as aciclovir, interferons such as β-interferon, renal excretion inhibitors such as probenicide, nucleoside transport inhibitors such as dipyridamole, 2 ', 3'-dideoxynucleosides such as 2', 3 '-ytide , 3 '-dideoxyadenosine, 2', 3'-dideoxyinosine, 2 ', 3'-dideoxythymidine and 2', 3'-dideoxy-2 ', 3'-didehydrotymidine and immunomodulators such as interleukin II (IL2) and granulocyte macrophage colonizing factor (GM-CSF), erythropoietin and ampligen.

The individual components of such combinations may be administered either sequentially or simultaneously in separate or combined pharmaceutical formulations.

When the compound of form (I) or a pharmaceutically acceptable derivative thereof is used in combination with a second therapeutic agent active against the same virus, the dose of each compound may differ from that given when the compound is used separately. Appropriate doses will be readily apparent to one skilled in the art.

Compounds of formula (I) and their pharmaceutically acceptable derivatives may be prepared by any of the methods known in the art for the preparation of compounds of analogous structure.

Suitable methods for the preparation of compounds of formula (I) and their pharmaceutically acceptable derivatives are described below; groups X and Z have the above definition except when otherwise stated. It should be understood that subsequent reactions | dv '13 1505 213 may require the use of, or suitably applied to, starting materials with protected functional groups and removal of these protected groups may thus be required as an intermediate step or final step to give the desired compound. Protection with and removal of functional groups can be achieved using conventional devices.

For example, amino groups may be protected with a group selected from aralkyl (eg benzyl), acyl or aryl (eg 2,4-dinitrophenyl); subsequent removal of the protecting group is accomplished when desired by hydrolysis or hydrogenolysis when appropriate using standard conditions.

Hydroxyl groups can be protected using any conventional hydroxyl protecting groups, as described, for example, in "Protective Groups in Organic Chemistry", Ed.

J.F.W. McOmie (Plenum Press, 1973) or "Protective Groups in Organic Synthesis" by Theodora W. Greene (John Wiley and Sons, 1989). Examples of suitable hydroxyl protecting groups include groups selected from alkyl (e.g., methyl, t- butyl or methoxymethyl), aralkyl (eg benzyl, diphenylmethyl or triphenylmethyl), heterocyclic groups such as tetrahydropyranyl, acyl (eg acetyl or benzoyl) and silyl groups such as trialkylsilyl (eg t-butyldimethylsilyl) The hydroxyl protecting groups can be removed by conventional techniques, for example, alkyl, silyl, acyl and heterocyclic groups can be removed by solvolysis, eg by hydrolysis under acidic or basic conditions, Aralkyl groups such as triphenylmethyl can also be removed by solvolysis, e.g. by hydrolysis under acidic conditions Aralkyl groups such as benzyl can be cleaved by hydrogenolysis in the presence of a noble metal catalyst such as palladium-on-charcoal.Silyl groups can also be conveniently removed using n source of fluoride ions such as tetra-n-butylammonium fluoride.

In a first process (A), compounds of formula (I) and pharmaceutically acceptable derivatives thereof, may be prepared by reacting a compound of formula (II). 505 213 14 fxnr fl l 'i -en //' \ / "" 2 N 0 '. Iz / \\ N / \ NH m) Y '° "2 \ /' \ ï TO ~ _._- Û (wherein X and Z are substituents with the meaning in formula (I) or are protected forms thereof and Y is OH or a protected form thereof) or a pharmaceutically acceptable derivative thereof with a reagent selected from formic acid and reactive derivatives thereof followed, where necessary, by the removal of undesired groups introduced by said reagent and / or by removal of any present protecting groups.

Examples of suitable formic acid derivatives which may be used in process (A) above include orthoformates (eg triethyl orthoformate), dialkoxymethyl acetate (eg diethoxymethyl acetate), dithiomyric acid, formamide, s-triazine or formamidine acetate.

Unwanted groups introduced by formic acid or a reactive derivative thereof can be conveniently removed by mild hydrolysis, for example using an inorganic acid such as aqueous hydrochloric acid.

When a trialkyl orthoformate such as triethyl orthoformate is used, this suitably also constitutes the solvent for the reaction.

Other solvents that may be used include amides (eg dimethylformamide or dimethylacetamide), chlorinated hydrocarbons (eg dichloromethane), ethers (eg tetrahydrofuran) or nitriles (eg acetonitrile).

In some cases (eg when a trialkyl orthoformate, such as triethyl orthoformate, is used), the reaction may preferably be carried out in the presence of a catalyst, such as a strong acid (eg concentrated hydrochloric acid, nitric acid or sulfuric acid).

The reaction can be carried out at a temperature in the range -25 to + 150 ° C, e.g. 0 to 10 ° C, and is conveniently carried out at room temperature.

In another process (B), the compounds of formula (I) and their pharmaceutically acceptable derivatives or a protected form thereof, are subjected to an interconversion reaction, whereby the parent substituent X present is replaced by another substituent X and / or the parent group Z present is replaced with another group Z followed, where necessary, by the removal of any protecting groups present.

According to an embodiment of process (B), the compounds of formula (I), wherein X represents a group NRRI (V fl ri R 0Ch R 1 has the definition given above) can be prepared by amination of a corresponding compound of formula (I), wherein X represents a halogen atom (eg chlorine). This amination can be accomplished by reaction with a reagent HNRRI (wherein R and R1 have the above definition) conveniently in a solvent, such as an alcohol (eg methanol). The reaction can be carried out at any temperature and is conveniently carried out at elevated temperature such as under reflux or, when liquid ammonia is used, in a sealed tube at about 50 to 80 ° C. Suitable conditions for the conversion of the halides to secondary or tertiary amines have also been described by I.T. Harrison et al, Compendium of Organic Synthetic Methods, Wiley-Inter- science, New York (1971) at pages 250-252.

According to another embodiment of process (B), the compounds of formula (I), wherein X represents a group OR (wherein R has the above definition) can be prepared by replacing the halogen (eg chlorine) atom with an appropriate anion RO-.

When R represents a hydrogen atom, the replacement reaction can be carried out by hydrolysis which can be effected in water or in a mixture of water and a water-miscible solvent such as an alcohol (eg methanol or ethanol). , an ether (eg dioxane or tetrahydrofuran), a ketone (eg acetone), an amide (eg dimethylformamide) or a sulfoxide (eg dimethylsulfoxide), suitably in the presence of a acid or a base. Suitable acids include organic acids such as p-toluenesulfonic acid and inorganic acids such as hydrochloric acid, nitric acid or sulfuric acid. Suitable bases include inorganic bases, such as alkali metal hydroxides or carbonates (eg sodium or potassium hydroxide or carbonate). Aqueous acids or bases can also be used as reaction solvents. The hydrolysis can conveniently be effected at a temperature in the range -10 to + 150 ° C, e.g. in return. When R represents a C 1-4 alkyl or aryl group, the anion RO is suitably formed from a corresponding alcohol ROH using an inorganic base such as an alkali metal (eg sodium metal) or an alkali metal hydride (eg sodium hydride). The reaction with the in situ formed anion can be conveniently effected at room temperature.

According to a further embodiment of process (B), compounds of formula (I), wherein X represents a group SH, may be prepared by reacting the halogen compound of formula (I) with thiourea in a suitable solvent, such as an alcohol (e.g. n -propanol) at elevated temperature (eg reflux) followed by alkaline hydrolysis. Suitable bases which may be used include alkali metal hydroxides (eg sodium hydroxide). The reaction may conveniently be carried out according to the method of G.G. Urquart et al., Org. Sight. Coll. vol. Ä, 363 (1953) e.g. by refluxing the intermediate product with aqueous NaOH for about 0.215 to about 5 hours.

According to another embodiment of process (B), the compounds of formula (I), wherein X represents a hydrogen atom, can be prepared by reducing the halogen compound of formula (I) using a reducing system which does not affect the rest of the molecule. Suitable reducing agents that can be used to effect the desired dehalogenation reaction include zinc metal / water using the method described by J.R. Marshall et al., J. Chem. Soc., 1004 (1951). Alternatively, the reaction may be effected by photolysis in a suitable solvent such as tetrahydrofuran containing 10% triethylamine and preferably in a Rayonet photochemical reactor (2537A) according to the method of V. Nair et al., J. Org. Chem., Et al., 1344 (1987).

According to a further embodiment of process (B), the compounds of formula (I), wherein X represents a halogen atom, may be prepared from another halogen compound of formula (I) according to conventional methods of halide-halide exchange.

Alternatively, when X is chlorine, this substituent may be replaced by another halogen atom using various β- (halo) benzenediazonium chlorides according to well known methods.

Compounds of formula (I), wherein X represents a group SR, wherein R is a C 1-4 alkyl or aryl group, may be prepared from the corresponding thiols using standard methods of alkylation or arylation, as described, for example, in U.S. Pat. no. 4 383 114.

The compounds of formula (I) wherein Z represents a hydroxyl group may conveniently be prepared from a corresponding compound of formula (I) wherein Z represents NH 2 by reaction with nitric acid, for example using the procedure used by J. Davoll in J. Amer . Chem. Soc., Lay, 3174 (1951).

Many of the reactions described above have been exhaustively reported in connection with purine nucleoside syntheses, for example in Nucleoside Analogs - Chemistry, Biology and Medical Applications, RT Walker et al., Eds, Plenum Press, New York (1979) on pages 193- 223, which is hereby incorporated by reference.

Pharmaceutically acceptable salts of the compounds of the invention may be prepared as described in U.S. Pat. 4,383,114, which is hereby incorporated by reference. Thus, for example, if it is desired to prepare an acid addition salt of a compound of formula (I), the product of any of the above processes may be converted into a salt by. r fri ww "505 213 18 treatment of the obtained free base with a suitable acid according to conventional methods. Pharmaceutically acceptable acid addition salts may be prepared by reacting the free base with an appropriate acid, optionally in the presence of a suitable solvent such as an ester (t. eg ethyl acetate) or an alcohol (eg methanol, ethanol or isopropanol) Inorganic basic salts can be prepared by reacting the free base with a suitable base such as an alkoxide (eg sodium methoxide) optionally in The presence of a solvent, such as an alcohol (eg methanol) Pharmaceutically acceptable salts may also be prepared from other salts including other pharmaceutically acceptable salts of the compounds of formula (I) using conventional methods.

A compound of formula (I) may be converted into a pharmaceutically acceptable phosphate or other ester by reaction with a phosphorylating agent such as POCl 3 or a suitable ester. agents such as an acid halide or anhydride, as appropriate. An ester or salt of a compound of formula (I) may, for example, be converted into the parent compound by hydrolysis.

The compounds of formula (II) and the salts thereof are novel compounds and constitute a further embodiment of the present invention.

The compounds of formula (II), wherein Z represents hydrogen or hydroxyl can be prepared directly from the compound 33 H2 '__- O 2a by reaction with an excess of a pyrimidine of formula (III) 41' z 19 -505 213 XIN // ° \ f (L 1 (III) Z / \ N / \ Y (wherein Y is a halogen atom, eg chlorine and Z is hydrogen or hydroxyl) in the presence of an amine base, such as triethylamine, and in an alcoholic solvent (t. eg n-butanol), preferably at reflux.

Compounds of formula (II), wherein Z represents NH 2 can be prepared using the compound of formula ga by reacting with an excess of a pyrimidine of formula (IV) fl '\ (IV) --Z GC QO /' H 2 N NY (wherein Y has the definition given in formula (III) above) under conditions similar to those described above for the preparation of compounds of formula (II), wherein Z represents hydrogen or hydroxyl, to a compound of formula (V): / ° \\ / ° \ H2N NH (v) rio-CMA / - \ I which can be diazotized using a diazonium salt ¿__ '_ __ sos 213 20 ArN2 + E_ (wherein Ar represents an aromatic group , eg p-chlorophenyl and E represents an anion (eg a halide such as chloride) in a solvent such as water, an organic acid such as acetic acid or a mixture thereof, suitably at about room temperature to a compound of the formula (VI) x I ø * \ / No '.! N / \ / \ H N = N-Year H2 Ho-cn (vi). (Wherein Ar has the definition just given above), which can be converted to the desired compound of formula (II) by, for example, reduction using a reducing metal, such as zinc, in the presence of an acid, e.g. acetic acid. It is recognized that the choice of reducing agent depends on the nature of the group X.

The compound ga can be prepared from the versatile precursor 1a-acetylamino-3-bacetoxymethylcyclopent-2-ene (1a) by hydrolysis in the presence of a mild base, such as an alkaline earth metal hydroxide.

A particularly suitable synthesis of the compounds of formula (I) via the 6-chloro compounds of formula (II) is given below. 21 ïsos 213 // \ _ / "" 2 1. ' Z / \\ N / \ NH HAC H2 AC ø H - H.

“W WT. “M 1___1 ___; | _ | _; ___> | _x la v 2a Ia 'fl 1 f // ° \ / \ // \ / Wz //' \ / '\ * j H --- \ O / - ° 1 * f 1' r - . \ CH HZN / \\ N / \ H2 / \\ N / \ Z / \\ / \ N ¿.

Compound ga and the compounds of formulas (V) and (VI) are novel intermediates and form further embodiments of the present invention.

The compound 1a is a known compound described in U.S. Pat. 4 138 562.

When the compound of formula (I) is desired as a single isomer, it may be obtained either by cleavage of the final product or by stereospecific synthesis from isomerically pure starting material or any suitable intermediate.

Cleavage of the final product or an intermediate or starting material therefor can be accomplished by any suitable method known in the art: compare, for example, "Stereochemistry of Carbon Compounds" by EL Eliel (McGraw Hill, 1962) and "Tables of Resolving Agents" by SH Wilen.

A suitable method of obtaining chirally pure compounds of formula (I) is by enzymatic transfer of a racemic mixture of the compound or a precursor thereof. By such a method, both the (+) and (-) compounds of formula (I) can be obtained in optically pure form. Suitable enzymes include deaminases, such as adenosine deaminase.

The invention is further illustrated by reference to the following detailed examples, in which elemental analyzes were performed by M-H-W Laboratories, Phoenix, AZ. Melting points were determined on a Mel-Temp apparatus and are corrected. Nuclear magnetic resonance spectra were obtained on Jeol FX 90QFT or Nicollet NT300 spectrometers and were noted in DMSO-d6. Chemical shifts are expressed in ppm downstream of Me4Si. IR spectra were determined as KBr pellets in a Nicollet SOXC FT-IR spectrometer and UV spectra were determined on a Beckman DU-8 spectrophotometer. Mass spectra were obtained with an AEI Scientific Apparatus Limited MS-30 mass spectrometer. Thin layer chromatography (TLC) was performed on 0.25 mm layer of Merck silica gel (230-400 mesh). All chemicals and solvents are of reagent type 11 u 'l' I! 23 ïsos 213 quality unless otherwise stated. The term "active ingredient" as used in the examples means a compound of formula (I) or a pharmaceutically acceptable derivative thereof.

L. 505 213 24 (f). M 'r- "Example 1 (I) - (Luy4d) -4 - [(5-amino-6-chloro-4-pyrimidinyl) -amino] -2-cyclopentenylcarbinol (3a) A mixture of 1M-acetylamino-Bdracetoxymethyl-cyclopent-2-ene (1a) (3.0 g, 15 mmol) and aqueous barium hydroxide (0.5N, 300 ml) was refluxed overnight. After cooling, it was neutralized with dry ice. The precipitate was filtered off and the aqueous solution was concentrated to dryness. The residue was extracted with absolute ethanol and concentrated again to give as a colorless syrup 1.6 g (14 mmol).

To this syrup was added 5-amino-4,6-dichloropyrimidine (4.59 g, 28 mmol), triethylamine (4.2 g, 42 mmol) and n-butanol (50 mL) and the mixture was refluxed for 24 hours. The volatile solvents were removed, the residue was absorbed onto silica gel (7 g), packed in a flash column (4.0 x 12 cm) and eluted with CHCl 3 -MeOH (20: 1) to give 2.69 g ( 74%) of compound 33; melting point 130-132 ° C. An analytical sample was obtained by recrystallization from ethyl acetate (EtOAc), mp 134-135 ° C Ms (30 ev, 20 ° C); m / e 240 and 242 (M + and M + + 2), 209 (M + '31), 144 (B +); IR: 3600-2600 (OH), 1620, 1580 (C = C, C = N); analysis. (clonuclullmc, H, N.

Example 2 (1) - (lu, 4a) -4 - [(2-amino-6-chloro-4-pyrimidinyl) -amino] -2-cyclopentenylcarbinol (4a) To 14 mmol of crude 2a (Example 1) was added 2- amino-4,6-dichloropyrimidine (3.74 g, 22.8 mmol), triethylamine (15 ml) and n-butanol (75 ml) and the mixture was refluxed for 48 hours.

The volatile solvents were removed, the residue was treated with methanol to separate the undissolved by-product (the double pyrimidine nucleoside). The methanol solution was absorbed onto silica gel (8 g) packed in a column (4.0 x 14 cm) and eluted with CHCl 3 -MeOH (40: 1) to give 1.52 g (42%) of crude 43. The product was recrystallized from ethyl acetate and gave 43; mp 132-134 ° C, Ms (30 ev, 200 ° c); m / e 240 and 242 (M + and M + + 2), 209 (M + - 31), 144 (B +); IR: 3600-3000 (NH 2, OH), 1620, 1580 (C = C, C = N); Analysis. (ClOH13ClN4) C, H, N.

Example 3 (1) - (1044d) -4 - ([(2-amino-6-chloro-5- (4-chlorophenyl) -azo] -4-pyrimidine dinyl-amino) -2-cyclopentenylcarbinol (Sa) A cold diazonium salt solution was prepared from p-chloroaniline (1.47 g, 11.5 mmol) in 3N HCl (25 mL) and sodium nitrite (870 mg, 12.5 mmol) in water (10 ml) This solution was added to a mixture of 1a (2.40 g, 10 mmol), acetic acid (50 ml), water (50 ml) and sodium acetate trihydrate (20 g) The reaction mixture was stirred overnight at room temperature. The yellow precipitate was filtered and washed with cold water until neutral, then air-dried in a fume hood to give 3.60 g (94%) of gg, m.p. 229 DEG C. (sonacracling). The analytical sample was obtained from acetone-methanol (1 L). : 2), mp 241-243 ° C (dec.) MS (30 ev, 260 ° C): m / e 378 and 380 (M + and M * + 2), 282 (E +), IR: 3600-50 ° (NH 2, one) , 1620, 1580 (C = C, C = N); Analysis (C 16 H 16 Cl 2 N 6 O) C, H, N.

Example 4 (1) - (lu, m1), 4 - [(2,5-diamino-6-chloro-4-pyrimidinyl) -amino] -2-cyclopentenylcarbinol (6a) A mixture of 53 (379 mg, 1 mmol), zinc dust (0.65 g, 10 mmol), acetic acid (0.32 ml), water (15 ml) and ethanol (15 ml) were refluxed under nitrogen for 3 hours. The zinc was removed and the solvents were evaporated. The residue was absorbed onto silica gel (2 g), packed in a column (2.0 x 18 cm) and eluted with CHCl 3 -MeOH (15: 1). A cut syrup was obtained.

Further purification from methanol-ether gave Qa as a crystalline crystal, 170 mg (see%), mp 168-170 ° C, Ms (30 cv, 220 ° C); m / c 255 and 257 (M + and M * +2), 224 (M + '31), 159 (B +); IR: 3600-3000 (NH 2, OH) 1620, 1580 (C = C, C = N); Analysis. (C10H144ClN5) C, H, N.

Example 5 (1) - (1a, 4 ') - 4- (6-chloro-9H-purin-9-yl) -2-cyclopentenyl-carbinol (7a) A mixture of 33 (1.30 g, 5 , 4 mmol), triethyl orthoformate (30 ml) and hydrochloric acid (12N, 0.50 ml) were stirred overnight at room temperature. The solvent was evaporated at 35 ° C in vacuo. To the residue was added aqueous hydrochloric acid (0.5N, 30 ml) and the mixture was stirred for one hour, the mixture was neutralized to pH 7-8 with 1N sodium hydroxide and was absorbed onto silica gel (8 g), packed in a column (4.0 x 8 cm) and eluted with CHCl 3 -MeOH (20: 1) to give white crystals of za, 1.2 g (82%). recrystallized from ethyl acetate to give za, mp 108-110 ° C, MS (30 ev, 200 ° C), m / e 250 and 252 (M + and M * + 2), 219 2800 (OH), 1600 (C = C (C 11 H 11 ClN 4 O) C, H, N.

Example 6 (:) - (lu, 4u) -4- (6-hydroxy-9H-purin-9-yl) -2-cyclopenteyl-carbinol (8a) A mixture of 1a (251 mg, 1 mmol) and aqueous sodium hydroxide (0.2N, 10 ml) was refluxed for 3 hours. After cooling, the reaction mixture was adjusted to pH 5-6 with acetic acid. The reaction mixture was absorbed onto silica gel (2 g) packed in a column (2.0 x 11 cm) and eluted with CHCl 3 -MeOH (10: 1) to give 105 mg (45%) of §a. The crude white product was recrystallized from water-methanol (3: 1) to give α, m.p. 248-250 ° C (dec.), Ms (30 ev, 300 ° C); m / e 232 (M +), 214, 136 (E +), IR; 3600-2600 (on), 1680, 1600 (C = O, C = C, C = N): Analysis. (C11H12N4O2) C, H, N.

Example 7 (:) - (10,4400-4- (6-amino-9H-purin-9-yl) -2-cyclopentenyl-carbinol (9a) Liquid ammonia was introduced into a bomb containing a solution of 7a (250 mg .1 mmol) in methanol (5 ml) at -8000.

The bomb was sealed and heated at 60 ° C for 24 hours. Ammonia and methanol were evaporated and the residue was recrystallized from water to give off-white crystals of ga, 187 mg (81%), m.p. 198-200 ° C. Ms (30 ev, 210 ° C) = m / e 231 (M +), 213 (M + '1a), 135 (B +); 1R = 3600-2600 (NH 2, on), 1700, 1600 (c = c, C = N); Analysis (C 11 H 13 N 5 O) C, H, N.

INN, 27 b 505 213 Example 8 (i) - (low, 4K) -4- (6-mercapto-9H-purin-9-yl) -2-cyclopentenylcarbinol (10a) A mixture of 1a (125 mg, 0.5 mmol), thiourea (40 mg, 0.64 mmol) and n-propanol (5 ml) were refluxed for 2 hours.

After cooling, the precipitate was isolated by filtration, washed with n-propanol and dissolved in sodium hydroxide (1N, ml). The solution was adjusted to pH 5 with acetic acid. The crude igâ (90 mg, 73%> is isolated again, m.p. 260-262 ° C (dec.) And recrystallized from N, N-dimethylformamide to give lgâ, m.p. 263-265 ° C (dec.) MS (30 ev, 290 ° c ) = m / e 248 (M +), 230 (M + "1s), 152 (E +), IR: 3600-3200 (OH), 3100, 2400 (SH), 1600 (C = C, C = N); (C 11 H 12 N 4 OS) C, H, N.

Example 9 (i) - (Layer 4M) -4- (2-amino-6-chloro-9H-purin-9-yl) -2-cyclopentenylcarbinol (13a) A mixture of 63 (1.4l g, 5, 5 mmol) of triethyl orthoformate (30 ml) and hydrochloric acid (12N, 1.40 ml) were stirred overnight.

The suspension was dried in vacuo. Dilute hydrochloric acid (0.5 N, 40 ml) was added and the mixture was reacted at room temperature for one hour. The mixture was neutralized to pH 8 with 1N sodium hydroxide and adsorbed on silica gel (7.5 g) packed in a column (4.0 x 10 cm) and eluted with CHCl 3 -MeOH (20: 1) to give off-white crystals of low, 1.18 g (80%). The crude product was recrystallized from ethanol to give low, mp 145-147 ° C, Ms (30 ev, 220 ° c) = m / e 265 and 267 (M + and M * + 2) 235 (M + '30), 169 (B +); IR: 3600-2600 (NH 2, on), 1620-1580 (c = c, C = N); Analysis (C 11 H 12 N 5 OCl, 3/4 H 2 O) C, H, N.

Example 10 (1) - (1M, 4a) -4- (2-amino-6-hydroxy-9H-purin-9-yl) -2-cyclopentenyl-carbinol (14a) A mixture of 13a (266 mg, 1 mmol) and aqueous sodium hydroxide (0.33N) was refluxed for 5 hours, absorbed into silica gel (2 g) packed in a column (2.0 x 7.5 cm) and eluted with CHCl 3 -MeOH (5: l). The crude product is recrystallized. sus 213 N V 'v' V V. was separated from methanol-water (1: 4) to give white crystals of lig, 152 mg (61%), mp 254-256 ° C (dec.).

Ms (30 ev, 20 ° C) = m / e 247 (M +), 217 (M + '30), 151 (E +), IR; 3600-2600 (NH 2, OH), 1700, 1600 (C = O, C = C, C = N); Analysis (c11H13N5O2.3 / 4H2O) c, H, N.

Example 11 (1) - (1,4,4-4- (2,6-diamino-9H-purin-9-yl) -2-cyclopentenylcarbinol (15a) Liquid ammonia was introduced into a solution of low (265 mg, 1 mmol) in methanol (10 ml) at -80 ° C in a bomb The bomb was sealed and heated at 75 ° C for 48 hours Ammonia and methanol were evaporated The residue was absorbed on silica gel (2 g), packed in a column (2.0 x 10 cm) and eluted with CHCl 3 -MeOH) (15: 1). The crude product was recrystallized from ethanol to give 196 mg (80%) of low, mp 152-155 ° C. MS (30 ev, 20 ° C) = m / e 246 (M +), 229 (M + '17>, 216 (m + '30), 150 (E +), IR: 3600-3000 (NH 2, OH), 1700, 1650, 1600 (C = O, C = C, C = N); Analysis (C 11 H 14 N 6 O) C, H, N.

Example 12 (1S, 4R) -4- (2,6-diamino-9H-purin-9-yl) -2-cyclopentenyl-carbinol / (1S, 4R) -4- (2,6-diamino-9H -purin-9-yl) -2-cyclopentene-methanol / - (a) Intermediate 1: (1R, 2S, 3R, SR) -3- [6-amino-9H-purin-9-yl] - 5 - [(1,1-dimethylethyl) -dimethylsilyloxy) methyl] -1,2-cyclopentanediol (-) Aristeromycinl (12.505 g), tert-butyldimethylsilyl chloride (7.8 g) and imidazole (12.96 g) in dry dimethylformamide (85 ml) was stirred at room temperature for 2.5 hours. The resulting solution was diluted with ethyl acetate (500 mL), then washed with water (3 x 100 mL) and brine (50 mL) before a white solid crystallized out. This was collected by filtration, washed with ethyl acetate, then dried in vacuo to give the title product (3.929): 1 H NMR (DMSO-d 6) 8.15 (1H), 8.09 (1H), 7.19 (2H) , 5.00 (1H), 4.72 (1H), 4.69 (1H), 4.36 (1H), 3.85 (1H), 3.67 (2H), 2.23 (1H), 2 .09 (1H), 1.79 (1H), 0.89 (9H), 0.07 (6H). 1 Journal of the American Chemical Society 1983, vol, 105, 4049-4055 .HV 29 # 505 213 (b) Intermediate 2: (4R, 3aS, 6R, 6aR) -4- / 6-amino-9H-purine-9 -yl / -6- [((1,1-dimethylethyl) -dimethylsilyloxy) methyl] -3α, 5,6,6a-tetrahydro-4H-cyclopenta-1,3-dioxol-2-thione.

A stirred suspension of intermediate 1 (3.45 g) in dry dimethylformamide (56 ml) was treated with 1,1'-thiocarbonyldiimidazole (3.3 g) to give a yellow solution. After 15.5 hours at room temperature, the resulting solution was combined with that of a previous experiment (6% scale) and the solvent was removed by evaporation. The residual oil was diluted with ethyl acetate (100 mL), then washed with water (2 x 20 mL) and brine (2V x 20 mL), dried (MgSO 4) and evaporated to a yellow solid. This was washed with diethyl ether (25 ml), collected by filtration, further washed with ether (25 ml), then dried in vacuo to give the title product as a pale cream solid (3.6l g); max (ethanol) 240.0 nm (Eíšm 459); 1 H NMR (DMSO-d 6) 8.27 (1H), 8.13 (1H), 7.33 (2H), 81 (1H), 5.37 (1H), 5.28 (1H), 3, 78 (2H), 2.60 (1H), 2.28 (2H), 0.90 (9H), 0.09 (6H). (c) Intermediate 3: (1 %% 4'S) -9- [4 - (((1,1-dimethylethyl) -dimethylsilyloxy) -methyl) -2-cyclopenten-1-yl] -9H-purine-6 -amine A solution of intermediate 2 (3.57 g) in dry tetrahydrofuran (25 ml) was treated with a solution of 1,3-dimethyl-2-phenyl-1,3,2-diazaphospholidine (4.94 g) in dry tetrahydrofuran (10 ml), then stirred at room temperature for 8 3/4 hours. The solvent was removed by evaporation. The residual oil was combined with that from a previous experiment (40% scale), then subjected to column chromatography on silica (200 g, Merck 7734), eluted with chloroform and then with chloroform-ethanol mixtures to give a white solid. This solid was washed with diethyl ether (25 ml) and then collected by filtration. The solid was further washed with ether (10 ml), then dried in vacuo to give the title product (1.47 g); Λ max (ethanol) 261.4 nm (λ 443); 1 H NMR (DMSO-d 6) 8.14 (1H), 8.00 (1H), 7.20 (2H), 6.12 (1H), 95 (1H), 5.60 (1H), 3, 66 (2H), 2.96 (1H), 2.69 (1H), 1.65 (1H), 0.74 (9H), 0.02 (6H). 'hr _. 505 215 3 ° (d) Intermediate 4: (1'R, 4'S) -9- [4 - (((1,1-dimethylethyl) -dimethylsilyloxy) methyl) -2-cyclopenten-1-yl] -9H -purine-6-amine, 1-oxide A solution of intermediate 3 (1.37 g) in chloroform (30 ml) was treated with 80-90% m-chloroperoxybenzoic acid (1.29 g), then stirred at room temperature in 3 hours. The solvent was removed by evaporation and the remaining gum was dissolved in ethyl acetate (10 ml). A white solid crystallized out. This solid and material recovered by evaporation of the filtrate were dissolved in chloroform (100 ml), then washed with saturated aqueous sodium bicarbonate solution (2 x 10 ml) and brine (2 x 10 ml). The aqueous slurries were re-extracted with chloroform (50 ml). The combined organic solutions were dried (MgSO 4) and then evaporated to a solid. This solid was washed with diethyl ether (25 ml) and then collected by filtration. The white solid was further washed with ether (10 ml), then dried in vacuo to give the title product (1.16 g); RHEX (ethanol) 235.4 nm (13 1334), 263.2 nm (δ 248), 300.2 nm (δ 75); 1 H NMR (1H), 8.02 (1H), 7.16 (2H), 6.21 (1H), 5.87 (1H), 5.72 (1H), 3.68 (2H), 3, 04 (1H), 2.82 (1H), 1.74 (1H), 0.89 (9H), 0.06 (GH). (e) Intermediate 5: (1'R, 4'S / -7- [4 - (((1,1-dimethylethyl) dimethylsilyloxy) methyl) -2-cyclopenten-1-yl] -2-imino-1,2 -dihydro- / 1,2,4 / oxadiazolo [3,2-i] -9H-purine hydrobromide A stirred, ice-cold suspension of intermediate 4 (1.08 g) in methanol (20 ml) was treated with a solution of cyanogen bromide (0.34 g) in methanol (20 ml) added over 5 minutes, after 15 minutes the suspension was allowed to warm to room temperature to give a solution, after 90 minutes the solvent was removed by evaporation and the residue was washed with diethyl ether (25 ml). and then collected by filtration The solid was further washed with ether (25 ml), then dried in vacuo to give the title product (1.37 g); Anx (ethanol) 228.2 nm (δ μM 530), 285.2 nm (p. 445): 1 H NMR (cnc13> 10.20 (1n), .02 (1H), 8.37 (1H), 6.25 (1H), 6.01 (1H), 5.90 (1H) , 3.69 PN 'f' 31 sos 213 (2H), 3.05 (1H), 2.86 (1H), 1.73 (1H), 0.86 (9H), 0.03 (6H). (f) Intermediate 6: (1'R, 4'S), 9- / 4 - (((1,1-dimethylethyl) dimethylsilyloxy) methyl) -2-cyclopentene-1 -yl / -6-cyanoimino-1,6-dihydro--1-methoxy-9H-purine A solution of intermediate 5 (1.36 g) in dimethylformamide (10 ml) was stirred at room temperature and then treated with triethylamine ( 1.2 ml). After 40 minutes, iodomethane (0.54 ml) was added to give a yellow solution. After 33/4 hours, the solvent was removed by evaporation. The residue was partitioned between ethyl acetate (100 ml) and water (20 ml). The organic solution was further washed with water (2 x 20 ml) and brine (20 ml), dried (MgSO 4) and evaporated to a solid. This solid was washed with diethyl ether (25 ml) and then collected by filtration. This white solid was further washed with ether (10 ml), then dried in vacuo to give the title product (0.865 g); Amax (ethanol) 227.2 nm (Eååm 449), 287.0 nm (Eïfâm 544); in NMR 8.23 (1H), 7.96 (1H), 6.24 (1H), 5.85 (1H), 5.65 (1H), 4.21 (3H), 3.66 (2H) , 3.04 (1H), 2.77 (1H), 1.68 (1H), 0.88 (9H), 0.05 (6H). (g) Intermediate 7: (1'R, 4'S) -9- [4 - (((1,1-dimethylethyl) -dimethylsilyloxy) methyl) -2-cyclopenten-1-yl] -6-methoxyamino-9H purin-2-amine A solution of intermediate 6 (802 mg) and 1,8-diazabicyclo- [5,4,0] undec-7-ene (0.45 ml) in ethanol (80 ml) was stirred and heated at backflow. The heating was stopped after 9 hours and the solution was allowed to stand at ambient temperature overnight. The solvent was removed by evaporation. The residual oil was combined with that from a previous experiment (4% scale), then subjected to column chromatography on silica (40 g, Merck 9385) eluting with chloroform and then with chloro-methanol mixtures to give a foam.

This foam was decomposed with diethyl ether (10 ml) and the resulting solid was collected by filtration. The solid was further washed with ether (5 ml); dried 1 '505 2213 32' v-ffm '1'- then in vacuo to give the title product (594 mg); jLmax (ethanol) 282.2 nm (Eââm 409); 1 H NMR (DMSO-d 6) 9.76 (1H), 7.32 (1H), 6.53 (2H), 6.08 (1H), 5.88 (1H), 5.26 (1H), 3 72 (3H), 3.61 (2H), 2.90 (1H), 2.50 (1H), 1.52 (1H), 0.83 (9H), 0.02 (6H). (h) Intermediate 8: (1S, 4R) -4- [2-amino-6-methoxyamino-9H-purin-9-yl] -2-cyclopentene-methanol A solution of intermediate 7 (356 mg) in tetrahydrofuran ( 35 ml) was stirred at room temperature and then treated with tetrabutylammonium fluoride (1.0M solution in tetrahydrofuran, 1.4 ml).

After 90 minutes, the reaction mixture was quenched with water (1 mL), then the solvents were removed by evaporation.

The residual oil was subjected to column chromatography on silica (20 g, Merck 7734) eluting with chloroform and then with chloroform-methanol mixtures to give the title product as a solid (243 mg); λmax (pH 6 buffer) 280.2 nm (δ 534); 1 H NMR (nm 50 -66) 9.75 (1n), 7.39 (1n), 6.52 (zn), 6.10 (1H), 5.84 (1H), 5.27 (1H), 4 73 (1H), 3.40 (ZH), 2.83 (1H), 2.55 (1H, 1.52 (1H). (1S, 4R) -4- / 2,6-diamino-9H- purine-9-phyl / -2-cyclopentene-carbinol A stirred, ice-cold solution of intermediate 8 (210 mg) in water (10 ml) and tetrahydrofuran (50 ml) was treated with aluminum amalgam / from aluminum (237 mg) and 0.5% aqueous mercury-chloride solution /, added in small portions over 15 minutes.

After 40 minutes, the stirred mixture was allowed to warm to room temperature. After 15 hours, the resulting mixture was filtered through kieselguhr to remove insoluble matter.

These were washed with water: tetrahydrofuran (1: 5, 60 ml). The combined filtrates were evaporated. The residue was subjected to column chromatography on silica (10 g, Merck 9385), eluting with chloroform-ethanol mixtures to give the title product as a foam (159 mg); / GUD -810 (c 1.04, methanol); 2 (pH 6 buffer) 255.0 nm (Eaâm 302), 280.8 nm (Eââm 381), 1N NMR (nmso-66) 7.61 (1a) , 6.66 (zn), 6.10 (in), 5.87 <1n),, 76 (ZH), 5.38 (1H), 4.76 (1H), 3.45 (2H), 2 , 87 (1H), 2.60 (1H), 1.60 (1H). Example 13 (50S, 4R) -4- (2-amino-6-hydroxy-9H-purin-9-yl) -2-cyclopentenyl-carbinol (1'R, 4'S), 2-Amino-1,9-dihydro-9- [4-hydroxymethyl-2-cyclopenten-1-yl] -6H-purin-6-one A cloudy solution of the title compound from Example 12 (144 mg) in 0.1M pH 6 buffer (10 ml) (from 28.4 g disodium orthophosphate in 2 liters of water, adjusted with orthophosphoric acid) was treated with a solution of adenosine deaminase (0.5 ml, 778 units) in 50% glycerol. 1.0 M potassium phosphate, pH 6.0, then stirred and heated to 370. After 18.5 hours, the resulting suspension was cooled. The recovered solid was recrystallized from water to give the title product as a white solid (see mg), / a7D1; 49 ° (C oís, dimethylsul1fox1d) = Amax (pa 6 buffer) 252.6 nm (Elcm 531), 1 H NMR ( nmso-α6>, 60 (1H), 7.60 (1H), 6.47 (2H), 6.10 (1H), 5.86 (1H), 5.33 (1H), 4.72 (1H) ), 3.45 (2H), 2.59 (1H), 1.58 (1H).

Example 14 Preparation of enantiomers of (lu, 4K) -4- (2-amino-6-hydroxy-9H-purin-9-yl) -2-cyclopentenylcarbinol (a) (1S, 4R) -4- (2- amino-6-hydroxy-9H-purin-9-yl) -2-cyclopentenyl-carbinol The diamine analog (100 mg) (Example 11) was dissolved in 3 ml of 0.05M K 2 PO 4 buffer (pH 7.4) under heating ( 50 ° C). The solution was cooled to room temperature and 40 units of adenosine deaminase (Sigma, type VI, calf intestinal mucosa) were added. After 3 days of incubation at room temperature, a precipitate formed which was removed by filtration, yield 18.2 mg. The filtrate was concentrated to 1.5 ml and cooled for 2 days. Additional solid was obtained by filtration, yield 26.8 mg. The two solid fractions were recrystallized from water to give the pure title product, mp 269-272 ° C, AX / E4 -62.1 ° (C 0.3 meon). 50 b 2013 (b) (1R, 4S) -4- (2-amino-6-hydroxy-9H-purin-9-yl) -2-cyclopentenyl-carbinol The filtrates from the preparation of 1S, 4R the isomer (Example 14a) was combined and evaporated to dryness. The unchanged diamine starting material was separated on a silica gel flash column using 10% methanol / chloroform. The diamino compound was dissolved in 0.05M K 2 PO 4 buffer, pH 7.4 (15 ml) and 800 units of adenosine deaminase were added. The solution was incubated for 96 hours at 37 ° C. TLC indicated that some unreacted product remained. The solution was heated in boiling water for 3 minutes and filtered to remove denatured protein. An additional 800 units of adenosine deaminase were added and the procedure was repeated. The deproteinized solution was evaporated to dryness and the product crystallized from water. The title product as a white solid was recovered by filtration from water, mp 265-270 °, / a7š4 +61.1 (c 0.3 meon).

Example 15 (i) - (lu, 4N) -4- (2-amino-6-hydroxy-9H-purin-9-yl) -2-cyclopentenyl-acetoxycarbinol To a suspension of the product of Example 10 (130 mg , 0.50 mmol) and 4-dimethylaminopyridine (5 mg, 0.04 mmol) in a mixture of acetonitrile (6 mL) and triethylamine (0.09 mL, 0.66 mmol) was added acetic anhydride (0.06 mL, 0 mL). , 6 mmol).

The mixture was stirred at room temperature for 3 hours. Methanol (1 ml) was added to quench the reaction. The solution was concentrated and absorbed onto silica gel (1.5 g), packed on a column (2.0 x 12 cm), eluting with CHCl 3 -MeOH (20: 1). The product fractions were collected and concentrated to give a white solid. The solid product was washed with MeOH-AcOEt: yield, 232 mg (85%). Further purification from methanol gave the title product as needle-like crystals, m.p. 237-239 ° C. Analysis (C 13 H 15 N 5 O 3) c, H, N. 'Ru f' W as 505 213 I Example 16 (1S, 4R) -4- [2-amino-9H-purin-9-yl] -2-cyclopentenylcarbinol A stirred, ice-cold solution of (1S, 4R) -4- [2-amino-6-methoxyamino-9H-purin-9-yl] -2-cyclopentene-methanol (intermediate 8, Example 12) (1.202 g) in tetrahydrofuran (250 ml) and water (50 ml) were treated with aluminum amalgam (from aluminum (1.76l g) and 0.5% aqueous mercury chloride solution), added in small portions over one hour and 47 minutes.

After 35 minutes, the stirred mixture was allowed to warm to room temperature. After 16 hours and 50 minutes, more aluminum amalgam (from 235 mg of aluminum) was added over 14 minutes.

After a further 4 hours and 10 minutes, the resulting mixture was filtered through kieselguhr to remove insoluble materials. These were washed with tetrahydrofuran water (5: 1, 300 ml). The combined filtrates were evaporated to give a yellow foam. The foam was subjected to column chromatography on silica (33.8 g, Merck 7734) prepared in chloroform and eluted with chloroform-ethanol mixtures to give several fractions (578 mg, 420 mg and 40 mg). The two larger fractions were crystallized separately from isopropanol. The filtrates were combined with the smallest column fraction and subjected to preparative thin layer chromatography (Merck 5717) developed three times in 10: 1 chloroform-methanol. The plates were eluted with ethyl acetate and ethyl acetate-ethanol (1: 1) to give a brown solid (45 mg fi. The solid was subjected to column chromatography on silica (2.7 g, Merck 7734) prepared in chloroform and eluted with chloroform-methanol-triethylamine mixtures to give a gummy product (17 mg) After unsuccessful crystallization from isopropanol and charcoal treatment in methanol, an aqueous solution of the recovered material was lyophilized to give the title compound (15 mg). 1 H NMR (DMSO-d 6) 1.62 (1H), 2.63 (1H), 2.89 (1H), 3.45 (2H), 4.73 (1H), 5.48 (1H), 5.91 (1H), 6 , 14 (1H), 6.50 (za), 7.98 (in), 8.57 (in). Mass spectrum, / nn / "L 232.

Example 17 Tablet formulations A: The following formulation was prepared by wet granulation of the ingredients with a solution of povidone in water, drying and screening, followed by addition of magnesium stearate and pressing. Mg / tablet (a) Active component 250 (b) Lactose, BP 210 (c) Povidone, BP 15 (d) Sodium starch glycolate 20 (e) Magnesium stearate 5 500 B. The following formulation was prepared by direct pressing: the lactose is of the type which can be pressed directly. mg / tablet Active component 250 Lactose 145 Avicel 100 Magnesium stearate 5 500 C. (Controlled release formulation) The formulation was prepared by wet granulation of the components (below) with a solution of povidone in water, drying and screening followed by addition of magnesium stearate and compression mg / tablet (a) Active component 500 (b) Hydroxypropyl methylcellulose (Methocel K4M Premium) ll2 (c) Lactose, BP 53 (d) Povidone, BP 28 (e) Magnesium stearate 7 700 I. Yuma 37 505 213 I Example l8 Ka psel formulation A capsule formulation is prepared by mixing the components below and filling into two-part hard gelatin capsules. mg / capsule Active component 125 Lactose 72.5 Avicel 50 Magnesium stearate 2.5 250 Example 19 Injectable formulation Active component 0.200 g Sodium hydroxide solution, 0.1M q.s. to a pH of about 11.

Sterile water q.s. to 10 ml.

The active component is suspended in a portion of the water (which may be hot) and the pH is adjusted to about 11 l with a solution of sodium hydroxide. The kit is then adjusted to volume and filtered through a sterilizing graduated membrane filter into a sterile 10 ml glass bottle and sealed with sterile seals and over-seals.

Example 20 Suppositories mg / suppository Active component (63 μm) 250 Hard fat, BP 1770 2020 One fifth of the hard fat is melted in a steam jacketed pan at 45 ° C maximum. The active component is sieved through a 200 μm sieve and added to the molten base by mixing, using a high shear stirrer until a dispersion is obtained. While maintaining the mixture at 45 ° C, the remaining hard fat is added to the suspension. sus 213 38 and stirred to ensure a homogeneous mixture. The entire suspension is passed through a 250 nm stainless steel sieve and allowed to cool to 40 ° C with continued stirring. 2.02 gnaw the mixture is filled into suitable 2 ml plastic molds.

The suppositories are allowed to cool at room temperature. Example 21 - Antiviral activity (A) Anti-HIV assay Compounds of formula (I) were screened for anti-HIV activity at the National Cancer Institute, Frederick Cancer Research Facility, Frederick, Maryland (FCRF). Listed below are the current screening procedures (screening mode operational procedures) used at FCRF. The protocol consists of three areas, (I) preparation of infected cells and distribution to the test plates, (II) preparation of drug dilution plates and distribution to the test plates, and (III) XTT assay procedure. Compare D.A. Scudiero et al., "A New Simplified Tetrazolium Assay for Cell Growth and Drug Sensitivity in Culture", Cancer Res., Ga, 4827, (1988).

I. Infection and distribution of ATH8 cells to microtiter dishes Cells to be infected (a normal lymphoblastoid cell line expressing CD4) are placed in conical 50 ml centrifuge tubes and treated for one hour with 1-Zlug / ml polybrene at 37 ° C. The cells are then pelleted for 8 minutes at 1200 rpm. HIV virus, diluted 1:10 in media (RMPI-1640, 10% human serum or% fetal calf serum (FCS), with IL-2 and antibiotics), is added to give an MOI of 0.001. Only medium is added to virus-free control cells. Assuming an infectious virus titer of 10-4 represents an MOI of 0.001 8 infectious virus particles per 10,000 cells. Approximately 500,000 cells / tube are exposed to 400 μl of the virus dilution. The resulting mixture is incubated for one hour at 37 ° C in air CO 2. The infected or uninfected cells are diluted to give 1 x -4 (with a human serum or 2 x 10-4 cells / 100 / ul. (With fetal calf serum) Infected or uninfected cells (100, u1) are distributed to appropriate wells by a 96-well, U-bottom microtiter plate.Each diluted compound is tested twice with infected cells.Uninfected cells are examined for on drug sensitivity in a single well for each dilution of the compound Drug-free control cells, inos 213 40 f '' dn-infected and non-infected are run in triplicate.Wells B2 to G2 serve as reagent control and were given only medium.

The plates are incubated at 37 ° C in air-CO 2 until drug is added.

II. Drug dilution and additive Dilution plates (flat bottom 96 wells, microtiter plates) are treated overnight with phosphate buffered saline (PBS) or media containing at least 1% FCS or 1% human serum (depending on the medium used in the test) starting on the day of analysis. This "blocking" method was used to limit the adsorption of the drug to the microtiter dishes during the dilution process. The wells are completely filled with the blocking solution and allowed to stand at room temperature in a humidified chamber under a hood.

The dilution procedure began by first diluting the test compound 1:20. Blocked dilution plates are prepared by flicking out the blocking solution and drying dry on sterile gauze. All wells in each plate are then filled with 225 μl of the appropriate medium using a Cetus liquid handling system. 25 microliters (25 μl) of each 1:20 diluted compound is then manually added to row A of a blocked and filled dilution plate. Four compounds, sufficient to provide two test plates, are added per dilution plate. The four compounds are then diluted in series 10 times from row A to row H using the Cetus fluid handling system. The initial dilution of each compound in row A at this point is 1: 200. The dilution plates are kept on ice until needed.

Using a multichannel pipette with 6 microtubes, 100 μl of each drug dilution is transferred to the test plates, which already contain 10 μl, ie medium plus cells. The final dilution in the test plate starts at 1: 400 (wells B4 to G4).

This dilution (to 0.25% DMSO) prevents the DMSO vehicle from interfering with cell growth. Drug-free, infected L 41k us 213 infected or non-infected cells (wells B3 to G3) and the reagent controls (B2 to G2) receive medium only. The two final compounds are then transferred from wells H7 to H12 to a second test plate using the same procedure. The test plates are incubated at 37 ° C in air-CO 2 for 7-14 days or until virus controls are lysed which is determined macroscopically.

III. Quantification of viral cytopathogenicity and drug activity A. Material 1. A solution of 2,3-bis / 2-methoxy-4-nitro-5-sulfophenyl / -5- [(phenylamino) carbonyl] -2H-tetrazolium hydroxide. (XTT) - 1 mg / ml solution in media without FCS. Storage at 4 ° C. Production every week. Phenazine Methosulfonate (PMS) stock solution - This can be prepared and kept frozen at -20 ° C until required. This should be done in PBS at a concentration of 15.3 mg / ml.

B. Microculture Tetrazolium Assay (MTA) 1. Preparation of XTT-PMS solution - XTT-PMS is prepared immediately before its addition to the wells of the culture dishes.

The stock PMS solution is diluted 100: 100 (0.53 mg / ml). Diluted PMS is added to each ml of XTT required to give a final PMS concentration of 0.02 mM. A 50 μl sample of the XTT-PMS mixture is added to each of the appropriate wells and the plate is incubated for 4 hours at 37 ° C. The plate seals are removed and replaced with adhesive plate sealing devices (Dynatech cat 001-010-3501). The sealed plates are shaken on a microculture plate mixer and the absorbance is determined at 450 nm.

IV. Results The data obtained were presented as a percentage of test cells compared to non-infected cells (%) for both infected and non-infected cells as a function of the increasing concentration of the test compound. f sus 2013 42 The data provided allow the calculation of an effective concentration (EC50) with respect to infected cells, an inhibitory concentration (IC50) with respect to normal cells and a therapeutic index (TI50).

The HIV inhibitory concentrations determined as described above for the compounds of Examples 7, 9, 10, 11 and 14 (b) are shown in Table 1.

Table 1 Compound Example Cell line ED50 ID50 TI50 9a 7 MT-2 2.3 50 21.4 l3a 9 MT-2 0.41 6.97 17.3 l4a 10 MT-2 0.15 100 667 l5a ll MT-2 2 , 9) 125) 42.7 (-) 14a 14 (b) CEM 0.66 189 284 Thus, the compounds of Examples 5 and 8 showed antiviral activity in this test.

A previous analysis performed at the Southern Research Institute gave a TI50 of approximately 200 when MT-2 cells were cultured with H9 / HILV-IIIB.

(B) Activity against Feline Leukemia virus Antiviral test for activity against FeLV-FAIDS was performed in 96-well plates (Corning) using 81C indicator cells in Iscove's Modified Dulbecco's medium supplemented with 10% + heat-inactivated fetal bovine serum (FBS). hours before the assay, the plates were inoculated with 8C cells at 5 x 103 cells / well. On the day of the assay, the cells were pretreated for 30 minutes at 37 ° C with DEAE-dextran (25 ug / ml) in 0.1 ml of Hanks balanced saline. This was removed and then 0.1 ml of growth medium containing 32 TCID 50 of FeLV-FAIDS, or 0.1 ml of growth medium alone, was added to each well. The virus was allowed to adsorb for one hour, then 0.1 ml of test or positive control compound (2 ', 3'-dideoxycytidine; ddC) or growth medium was added. The plates were incubated at 37 ° C. The cells were fed with fresh growth medium containing the compound on day 4 after infection. The culture medium was completely changed and replaced with fresh medium containing the compound on day 7 after infection. On day 10 after infection, the cells were fixed with formalin, stained with 0.1% Coomassie Brilliant Blue R-250, and observed microscopically for CPE and drug cytotoxicity.

The compound of Example 10 had an ED 50 of 1.8 g / ml.

(C) Activity against murine AIDS Falcon 6 well tissue culture plates were inoculated with 1.75 x 10 5 cells per well in a total volume of 2.5 ml EMEM containing% heat inactivated FBS. 24 hours after the cells were inoculated, the medium was decanted and 2.5 ml of DEAE-dextran (25, ng / ml in phosphate buffered saline) was added to each well.

The cultures were incubated at 37 ° C for one hour, after which the DEAE-dextran solution was decanted and the cell layers were rinsed once with 2.5 ml of PBS. Normal cell controls were reconstituted with only 2.5 ml of medium (no virus or drug). Drug control cultures received 2.5 ml of medium containing drug but no virus. Virus-infected control cultures received 0.5 ml of the appropriate dilution of strain CAS-BR-M for the production of countable plaques plus 2.0 ml of medium. The test specimens received 0.5 ml of the appropriate virus dilution plus 2.0 ml of drug dilution medium. Six concentrations of the test compound diluted in half-loglo dilutions in series were tested. Three concentrations of the positive control drug, ddC, were tested. Triplicate wells for each concentration of test compound and 6 viruses and 6 cell control cultures were included in each assay. On day 3, post-virus inoculation toxicity of the drug to the SC-1 cells was determined by microscopic examination of spotted duplicate cells and drug control cultures. The remaining test and control cultures were irradiated with an ultraviolet lamp for 20 seconds and XC cells were added to each culture (5 x 105 cells / well in 2.5 ml EMEM containing 10% heat-inactivated FBS). On day 3 after UV irradiation, the cultures were fixed with formalin and stained with crystal violet. The plaques were counted using a dissecting microscope.

Antiviral activity in CAS-BR-M plaque reduction was expressed as a reduction in the mean number of plaques counted in drug-treated virus-infected cultures compared with the mean number of plaques calculated in the untreated virus-infected control cultures (% control). The compound of Example 10 had an ED 50 of 1.1 μg / ml.

(D) Activity against Simian retrovirus SAIDS (SRV-2) Antiviral screening against SAIDS virus (D / Washington) was performed with a syncytia inhibition assay on Raji cells. The drug was completely diluted in Iscove's medium and then 100 μl of each dilution was added to the appropriate wells in a 96-well plate. Actively growing Raji cells, x 103 cells in 50 lp1 complete Iscove's medium, were then added to each well. This was followed by the addition of 50 ul of clarified supernatant from an SRV-2 / Raji cell co-culture.

DDC was included in this assay as a positive control drug.

The plates were incubated at 3700 in a humidified atmosphere containing% CO 2. Syncytia was counted on day 7 after infection. Drug toxicity was determined by comparing live cell counts of the uninfected drug-treated sample with the viability of the uninfected untreated control. The compound of Example 10 had an ED 50 of 2.8 pg / ml.

(E) Activity against Visna Maedi virus The antiviral activity against Visna Maedi virus (VMV) strain WLC-1 was determined by measuring the reduction of virus-specific immunohistochemical staining. Monolayers of sheep choroid plexus cells were infected with VMV and overlaid with serial dilutions of the test compounds. After incubation for 5 days, the monolayers were further coated with virus-specific antisera conjugated to horseradish peroxidase (HRP). Subsequent incubation of the monolayers with a chromogenic substrate of HRP, the stem regions of virus replication. These discrete foci were counted and the concentration of the test compound required to reduce the number of foci to 50% for the drug-treated controls was calculated.

The compound of Example 13 had an ED 50 of 0.2 μg / ml.

Example 22 Cytotoxic Activity The compounds of Examples 5, 7 and 8 showed cytotoxic activity when tested against the P388 mouse leukemia cell culture assay as described by R.G. Alonquist and R. Vince, J. Med. Chem., 16, 1396 (1973). The ED50 obtained (mg / ml) was: Example 5 12 Example 7 40 Example 8 3

Claims (18)

A compound of the formula (I) 0 O / \\ N / \ (1) wherein X is hydrogen, NRRI, SR, OR or halogen; Z is hydrogen, OR 2 or NRR 1; R 1, R 1 and R 2 may be the same or different and are selected from hydrogen, C 1-4 and pharmaceutically acceptable derivatives thereof. alkyl and aryl; A compound of formula (I) according to claim 1 and pharmaceutically acceptable salts thereof. A compound according to claim 1 or 2, wherein in the compound of formula (I) Z is H, OH or NH 2. A compound according to any one of claims 1-3, wherein Z is NH 2. A compound according to any one of claims 1-4, wherein X is hydrogen, chlorine, NH 2, SH or OH. A compound according to any one of claims 1-5, wherein X is OH. A compound according to any one of claims 1-5, wherein X is H or NH 2. -_ .__ a »_ 505 213 A compound selected from: (1d, 4β) -4- (6-chloro-9H-purin-9-yl) -2-cyclopentenyl-carbinol; (lu, 4N) -4- (6-hydroxy-9H-purin-9-yl) -2-cyclopentenyl-carbinol; (1- [4]) 4- (6-amino-9H-purin-9-yl) -2-cyclopenteyl-carbinol; (lu, 4K) -4- (6-mercapto-9H-purin-9-yl) -2-cyclopentenyl-carbinol; (1d, 4 (J-4- (2,6-diamino-9H-purin-9-yl) -2-cyclopentenyl-carbinol) (1M, 4H-4- (2-amino-6-chloro-9H -purin-9-yl) -2-cyclopenteyl-carbinol, and (1,4,4NJ-4- (2-amino-9H-purin-9-yl) -2-cyclopenteyl-carbinol. 9. (lu, 4 «) - 4- (2-amino-6-hydroxy-9H-purin-9-yl) -2-cyclopentenyl-carbinol. 10. lO. A compound according to any one of claims 1-9 substantially in the form of a racemic mixture. 11. ll. A compound according to any one of claims 1-9 consisting essentially of an optical isomer. A compound according to any one of claims 1 to 9 consisting essentially of the D-isomer. A compound of formula (I) as defined in any one of claims 1 to 12 or a pharmaceutically acceptable derivative thereof for use as an active therapeutic agent. A compound of formula (I) as defined in any one of claims 1 to 12 or a pharmaceutically acceptable derivative thereof for use in the manufacture of a medicament for the treatment of a viral infection. A pharmaceutical preparation comprising a compound of formula (I) as defined in any one of claims 1 to 12 or a pharmaceutically acceptable derivative thereof together with a pharmaceutically acceptable carrier therefor. sus 213 4 * A pharmaceutical preparation comprising a compound of formula (I) as defined in any one of claims 1 to 12 or a pharmaceutically acceptable salt thereof together with a pharmaceutically acceptable carrier therefor. A pharmaceutical preparation according to claim 14, which further contains an additional therapeutic agent. A compound of formula (II) wherein X is hydrogen, NRR 1, SR, OR, halogen or protected forms thereof; Y is OH or a protected form thereof; Z is hydrogen, OR 2, NRR 1 or protected forms thereof; R 1, R 1 and R 2 may be the same or different and are selected from hydrogen, C 1-4 alkyl and aryl and pharmaceutically acceptable derivatives thereof.