LU87437A1 - DIDEOXYDIDEHYDROCARBOCYCLIC NUCLEOSIDES AND PHARMACEUTICAL COMPOSITION CONTAINING THEM - Google Patents

Description

The present invention relates to analogs of the type of dideoxydidehydrocarbocyclic nucleosides. It relates more particularly to analogs of the type of carbocyclic nucleosides of 21,31-dideoxy-2 ', 3'-didehy-5 dropurine and to their use in therapy, in particular as antiviral agents.

Due to the similarity between viral and host cell functions, it is difficult to selectively attack a virus while leaving the host cells intact. There are therefore relatively few agents effective against viruses proper, and it is difficult to find antiviral agents with a suitable therapeutic index, i.e. agents which produce a significant antiviral effect at a rate of dose for which the agent has an allowable toxicity profile or side effects.

A group of viruses which have become of major importance in recent times includes the retroviruses responsible for acquired immunodeficiency syndrome (AIDS) in humans. These viruses have already been designated according to various terminologies, but they now correspond to the general name of human immunodeficiency virus (HIV); two of these viruses, HIV-I and HIV-II, have been reproducibly isolated from patients with AIDS and related conditions such as the AIDS-related complex 2 (ARC) and persistent generalized lymphadenopathy.

Although a number of nucleosides have been taught as substances useful in the treatment of conditions associated with HIV virus infections, only zidovudine (AZT, Retrovir) has received regulatory approval for the treatment of such conditions . However, it is known that zidovudine produces serious side effects, resulting in the suppression of bone marrow, which leads to a decrease in the number of leukocytes accompanied by pronounced anemia, and it is necessary to find agents less cytotoxic.

The Applicant has just found a new class of analogs of the nucleoside type endowed with antiviral activity. Consequently, the invention proposes, according to a first aspect, a compound of formula (I)

X

ί N

/ vv i / ") Z N N H0-CH? ·.

NJ

\ _ / • - · in which X is hydrogen, a group NRR1, SR, OR or a halogen? Z is hydrogen, an OR2 or NRR1 group; R, R1 and R2 may be the same or different and are selected from hydrogen, C1-4alkyl groups and aryl groups; and pharmaceutically acceptable derivatives of this compound.

Those skilled in the art will recognize that the 13 compounds of formula (I) are cis compounds and further that the cyclopentene ring of the compounds of formula (I) contains two centers of chirality (designated in formula (I) by the sign *) and that they can therefore exist in the form of two optical isomers (i.e. enantiomers) and in the form of their mixtures, including racemic mixtures . All these isomers and their mixtures, including racemic mixtures, come within the scope of the invention. Thus, in the compounds of formula (I), the center of chirality to which the base is attached to the R configuration and the center of chirality to which the group CH20H is attached to the S configuration (D isomer below) or else the center of chirality to which the base is attached to the S configuration and the center of chirality to which the CH2OH group is attached to the R configuration (L isomer below). The compounds are advantageously in the form of a racemic mixture or mainly in the form of the pure D isomer. The D isomers can be represented by the formula (la)

X

I N

/ v \ 1! } (the)

Z N N H0-CH, yv I

i ^ N

\ _ / • _ · in which X and Z are as defined for formula (I). The references which are made below to compounds; of formula (I) include compounds of formula (la).

Those skilled in the art will also appreciate the fact that some of the compounds of formula (I) can exist in several tautomeric forms and that all of these 4 tautomers fall within the scope of the invention.

The term halogen used in this specification means fluorine, chlorine, bromine and iodine; when X is halogen, it is preferably chlorine.

The expression C1-C4 alkyl used in this specification refers to a straight-chain or branched-chain alkyl group, for example methyl, ethyl, n-propyl, isopropyl, n-butyl, sec.-butyl and tert-10 butyl. The C1 to C4 alkyl group is advantageously a methyl group.

The term aryl used herein refers to any monocyclic or polycyclic aromatic group and includes unsubstituted and substituted aryl groups (such as phenyl, tolyl, xylyl, anisyl) and unsubstituted and substituted aralkyl groups including ar groups (C1-4alkyl) such as phen- (C1-4alkyl), for example benzyl or phenethyl.

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

In a first appreciated class of compounds of formula (I), X is an OR group, in particular an OH group.

In another preferred class of compounds of formula (I), X is an NRR · * - group, especially NH2, or a hydrogen atom.

Particularly preferred compounds of formula (I) are those in which Z is an NH2 group and X represents H, NH2 or in particular an OH group. It is in particular these compounds which have particularly appreciable therapeutic indices as antiviral agents.

The term "pharmaceutically acceptable derivative" means any pharmaceutically acceptable salt, ester or salt of such ester, of a compound of formula (I) or any other compound which, for example, administration to the patient, is capable of providing (directly or indirectly) a compound of formula (I) or a metabolite or a residue endowed with antiviral activity of this compound -

Preferred esters of the compounds of formula (I) include esters of carboxylic acids in which the non-carbonyl portion of the ester group is chosen from hydrogen, straight chain or branched chain allcyl groups (for example methyl, ethyl , n-propyl, tert-butyl, n-butyl), alkoxyalkyl (for example methoxymethyl), aralkyl (for example benzyl), aryloxyalkyl (for example phenoxymethyl), aryl (for example phenyl optionally substituted by halogen) groups C1-C4 alkyl or C1-C4 alkoxy); sulfonic esters such as alkyl- or aralkylsulfonyl (e.g. methanesulfonyl); amino acid esters (e.g. L-valyl or L-isoleucyl) and monophos esters -phoric, diphosphoric or triphosphoric.

As regards the esters defined above, unless otherwise specified, any alkyl group present advantageously contains 1 to 18 carbon atoms, in particular 1 to 4 carbon atoms. Any aryl group present in such esters advantageously comprises a phenyl group.

Pharmaceutically acceptable salts of the compounds of formula (I) include those which are derived from pharmaceutically acceptable inorganic and organic acids and bases. Examples of suitable acids include hydrochloric, hydrobromic, sulfuric, nitric, perchloric, fumaric, maleic, phosphoric, glycolic, lactic, salicylic, succinic, toluene-p-sulfonic, tartaric, acetic, citric acids. methanesulfonic, formic, benzoic, maloni-35 que, naphthalene-2-sulfonic and benzenesulfonic. Other 6 acids such as oxalic acid, although not pharmaceutically acceptable in themselves, may be useful in the preparation of salts which can be used as intermediate compounds for obtaining the compounds of the invention 5 and of their pharmaceutically acceptable acid addition salts.

Salts derived from suitable bases include salts of alkali metals, eg sodium, alkaline earth metals (eg magnesium), ammonium and NR4 + (where R is a C4 alkyl radical).

When reference is made below to a compound according to the invention, this reference includes both the compounds of formula (I) and their pharmaceutically acceptable derivatives.

Representative compounds of formula (I) include the following: (la, 4a) -4— (6-chloro-9H-purine-9-yl) -2-cyclopen-tenylcarbinol î (1α, 4α) -4- ( 6-hydroxy-9H-purine-9-yl) - 2-20 cyclopentenylcarbinol; (la, 4a) -4- (6-amino-9H-purine-9-yl) -2-cyclopentenylcarbinol; (la, 4a) -4- (6-mercapto-9H-purine-9-yl) -2-cyclopentenylcarbinol; 25 (1α, 4α) -4 - (2-amino-6-chloro-9H-purine-9-yl) -2-cyclopentenylcarbinol; (la, 4a) -4- (2-amino-6-hydroxy-9H-purine-9-yl) -2-cyclopentenylcarbinol; (1α, 4α) -4- (2,6-diamino-9H-purine-9-yl) - 2-30 cyclopentenylcarbinol; as a racemic mixture or as an individual enantiomer.

The compounds of the invention themselves have antiviral activity and / or can be metabolized to such compounds. In particular, these compounds are effective in inhibiting the replication of retroviruses, including human retroviruses such as the human immunodeficiency viruses (HIV), agents responsible for AIDS.

Other compounds of the invention have anticancer activity, especially those in which X is hydrogen.

According to another aspect of the invention, there is therefore provided a compound of formula (I) or a pharmaceutically acceptable derivative of this compound, intended for use as an active therapeutic agent, in particular as an antiviral agent, for example in the treatment retrovirus infections, or as an anticancer agent.

In another aspect, or alternatively, there is provided a method of treating a viral infection, particularly an infection caused by a retrovirus such as HIV, in a mammal including humans, which comprises administering an effective amount of an antiviral compound of formula (I) or a pharmaceutically acceptable derivative of such a compound.

It is also proposed according to another aspect or as a variant the use of a compound of formula (I) or of a pharmaceutically acceptable derivative of this compound for the preparation of a medicament intended for the treatment of a viral infection or its use as an anticancer agent.

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

The antiviral compounds of the invention are also useful in preventing the progression of clinical disease in subjects who are positive for anti-HIV antibodies or HIV antigens and in prophylaxis following exposure to viruses HIV.

The antiviral compounds of formula (I) or their pharmaceutically acceptable derivatives can also be used in the prevention of viral contamination of physiological fluids such as blood or sperm in vitro.

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

Those skilled in the art will understand that when reference is made in this specification to treatment, it covers prophylaxis as well as the curative treatment of established infections or symptoms.

It should also be noted that the amount of a compound of the invention which is to be used in a treatment varies not only depending on the particular compound which is chosen, but also with the route of administration, the nature of the condition being treated and the age and condition of the patient, and that it is ultimately at the discretion of the attending physician or veterinarian. In general, however, a suitable dose is in the range of about 1 to about 750 mg / kg, for example a range of about 10 to about 750 mg / kg body weight, such as a range of 3 at about 120 mg per kilogram of body weight of the patient per day, preferably in the range of 6 to 90 mg / kg / day, especially in the interval from 15 to 60 mg / kg / day.

The desired dose can advantageously be presented in a single dose or in divided doses administered at appropriate intervals, for example two, three, four or more than four dose fractions per day. The compound is advantageously administered in a unit dosage form, containing for example 10 to 1500 mg, better still 20 to 1000 mg, in particular 50 to 700 mg of active ingredient per unit dosage form.

Ideally, the active ingredient 5 should be administered so as to achieve maximum concentrations of the active compound in the plasma of from about 1 to about 75 μΜ, better still from about 2 to 50 μΜ, especially from about 3 to about 30 μΜ. This can be achieved for example by intravenous injection of a 0.1-5% solution of the active ingredient: 10, optionally in physiological salt solution, or by oral administration in the form of a bowl containing approximately 1 to approximately 100 mg / kg of active ingredient. Adequate blood levels can be maintained by continuous infusion to provide about 0.01 to about 5.0 mg / kg / hour or by intermittent infusions providing about 0.4 to about 15 mg / kg of active ingredient .

Although it is possible that a compound of the invention, for use in therapy, can be administered as a crude chemical compound, it is preferable that the active ingredient be presented as a pharmaceutical formulation.

The invention therefore further provides a pharmaceutical formulation comprising a compound of formula (I) or a pharmaceutically acceptable derivative of this compound together with one or more pharmaceutically acceptable carriers and, optionally, other therapeutic and / or prophylactic ingredients . The carrier (s) should be "acceptable" in the sense that they should be compatible with the other ingredients of the formulation and should not harm the recipient.

Pharmaceutical formulations include formulations suitable for oral, rectal, nasal, topical (including buccal and sublingual), vaginal or parenteral (intramuscular and intravenous) administration or in a form suitable for administration by inhalation or insufflation. In appropriate cases, the formulations can be conveniently presented in physically separate dosage units and can be prepared by any of the methods well known in the pharmacy field. All of the methods involve the step of bringing the active compound into association with liquid carriers or finely divided solid carriers or both and then, if necessary, forming the product into the desired formulation.

Pharmaceutical formulations which are suitable for oral administration may advantageously be presented in physically separate units such as capsules, cachets or tablets each containing a predetermined amount of the active ingredient; in the form of a powder or granules; in the form of a solution, a suspension, or in the form of an emulsion. The active ingredient can also be presented in the form of a bowl, an electuary or a paste. Tablets and capsules for oral administration may contain conventional excipients such as binders, fillers, lubricants, disintegrating agents or wetting agents. The tablets can be coated according to methods well known in the art. Oral liquid preparations can be, for example, in the form of suspensions, solutions, emulsions in water or in oil, syrups or elixirs, or they can be presented in the form of a dry product to be mixed with water or other suitable vehicle before use. Such liquid preparations can contain conventional additives such as suspending agents, emulsifiers, non-aqueous vehicles (which may include edible oils) or preservatives.

The compounds according to the invention can also be formulated for parenteral administration (for example by injection, in the form of a bowl or by continuous infusion) and they can be presented in unit dosage form in ampoules, in pre-loaded syringes or in containers containing multiple doses, with the addition of a preservative. The compositions can affect forms such as suspensions, solutions or emulsions in oily or aqueous vehicles, and can contain formulating agents such as suspending agents, stabilizing agents and / or dispersing agents. Alternatively, the active ingredient may be in the form of powder, obtained by aseptic isolation of sterile solid material or by lyophilization from a solution, of powder to be mixed with a suitable carrier, for example l sterile pyrogen-free water before use.

For local administration on the epidermis, the compounds according to the invention can be formulated as ointments, creams or lotions, or as a transdermal adhesive dressing. Ointments and creams can, for example, be formulated with an aqueous or oily base added with suitable thickening and / or gelling agents. Lotions can be formulated with an aqueous or oily base and they also generally contain one or more emulsifying agents, stabilizing agents, dispersing agents, suspending agents, thickening agents or coloring agents.

Formulations suitable for local administration in the mouth include tablets containing the active ingredient in a flavored base, usually sucrose and gum arabic or gum tragacanth; lozenges comprising the active ingredient in an inert base such as gelatin and glycerin or sucrose and gum arabic; and mouthwash compositions comprising 11 active ingredient in a suitable liquid carrier.

Pharmaceutical formulations which are suitable for rectal administration the support of which is a solid material are very advantageously presented as suppositories containing a unit dose. Suitable carriers include cocoa butter and other materials commonly used in the art, and suppositories can be conveniently formed by adding the active compound to one or more softened or melted carriers, followed by cooling. and forming in molds.

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

For intranasal administration, the compounds of the invention can be used as a sprayable liquid composition or in the form of drops.

Drops can be formulated with an aqueous or non-aqueous base also comprising one or more dispersing agents, solubilizing agents or suspending agents. Sprayable liquid compositions are conveniently delivered using pressure vessels.

For administration by inhalation, the compounds according to the invention are conveniently delivered by an insufflator, a nebulizer or a pressurized container or by other practical means making it possible to deliver a spray jet in aerosol. Pressure vessels may contain a suitable propellant such as dichlorodifluoromethane, trichlorofluoromethane, 13 dichlorotetrafluoroethane, carbon dioxide or other suitable gas. In the case of a pressurized aerosol, the metered unit can be determined using a valve designed to deliver a measured quantity.

Alternatively, for administration by inhalation or insufflation, the compounds according to the invention may take the form of a dry powder composition, for example a powder mixture of the compound and a suitable powder base. such as lactose or starch. The powder composition can be presented in unit dosage form for example in capsules or cartridges or for example in gelatin envelopes or in the form of blisters, of which the powder can be administered using an inhaler or 'an insuff-15 flator.

When desired, the formulations described above can be used in a form suitable for allowing sustained release of the active ingredient.

The pharmaceutical compositions according to the invention can also contain other active ingredients such as antimicrobial agents or preservatives.

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

According to another of its aspects, the invention therefore provides an association formed of a compound of formula (I) or of a physiologically acceptable derivative of this compound with another agent endowed with therapeutic activity, in particular an antiviral agent .

The associations referred to above can advantageously be presented,. t 14 for their use, in the form of a pharmaceutical formulation and, consequently, pharmaceutical formulations comprising an association as defined above together with a phar-5 maceutically acceptable support constitute another aspect of the invention .

Advantageous therapeutic agents for use in these combinations include acyclic nucleosides such as aciclovir, interferons such as α-10 interferon, renal excretion inhibitors such as probenicid, nucleoside transport inhibitors such as as dipyridamole, 2 ', 3'-dideoxynucleosides such as 2', 3 '-dideoxycytidine, 2', 3 '-dideoxyadenosine, 2', 3 '-dideoxyinosine, 2', 3 '-dideoxythymidine and 2 ', 3' -dideoxy-2 ', 3' -didehydrothymidine and immunomodulators such as interleukin II (IL2) and granulocyte macrophage colony stimulating factor (GM-CSF), erythropoietin and the ampligene.

The individual components of these combinations can be administered successively or simultaneously in separate or combined pharmaceutical formulations.

When the compound of formula (I) or a pharmaceutically acceptable derivative of this compound is used in combination with a second therapeutic agent active against the same virus, the dose of each compound may be different from that used when using the compound alone. Appropriate doses are readily appreciated by those skilled in the art.

The compounds of formula (I) and their pharmaceutically acceptable derivatives can be prepared by any process known in the field of the preparation of compounds of analogous structure.

Suitable methods for preparing the compounds of formula (I) and their pharmaceutically acceptable derivatives are described below; groups X and Z

15 are as defined above, unless otherwise specified. It should be noted that the following reactions may require the use of starting materials, or may be conveniently applied to starting materials which carry protected functional groups, and therefore removal of the protecting groups may be necessary as a step. intermediate or final step to obtain the desired compound. The protection and elimination of the protection of functional groups can be carried out by conventional means. Thus, for example, amino groups can be protected by a group chosen from aralkyl (for example benzyl), acyl or aryl (for example 2,4-dinitrophenyl) radicals; the subsequent removal of the protective group being effected at the appropriate time by hydrolysis or hydrogenolysis, as appropriate, under normal conditions. Hydroxyl groups can be protected by the use of any conventional group protecting a hydroxyl group, as described for example in "Protective Groups in Organic Chemistry", published under the direction of J.F.W. McOmie (Plenum Press, 1973) or "Protective Groups in Organic Synthesis" by Theodora W. Greene (John Wiley and Sons, 1981). Examples of groups suitable for protecting hydroxyl groups include groups selected from alkyl radicals ( e.g. methyl, tert-butyl or methoxymethyl), aralkyl (e.g. benzyl, diphenylmethyl or triphé-nylmethyl), heterocyclic groups such as tetrahy-dropyrannyl, acyl groups (e.g. acetyl or benzoyl) and silyl groups such as trialkylsilyl groups (for example tert-butyldimethylsilyl). Groups protecting hydroxyl functions can be removed by conventional techniques. Thus, for example, alkyl, silyl, acyl and heterocyclic groups can be removed by solvolysis, for example by 16 hydrolysis under acidic or basic conditions. Aralkyl groups such as triphenylmethyl can likewise be eliminated by solvolysis, for example by hydrolysis da ns acidic conditions. Aralkyl groups such as benzyl can be cleaved by hydrogenolysis in the presence of a catalyst based on a noble metal such as palladium fixed on carbon. Silyl groups can also be conveniently removed using a source of fluoride ions such as tetra-n-butylam-10-monium fluoride.

In a first process (A), compounds of formula (I) and their pharmaceutically acceptable derivatives can be prepared by reaction of a compound of formula (II)

X

At Γ2 N · I. »/ \ Λ z N NH (II) H0-CH9 v • i

I I

• _ · 15 (in which X and Z are substituents having the definition given for formula (I) or are protected forms thereof and the hydroxyl group in the cyclopentenylcarbinol group may be in a protected form) or of a pharmaceutical derivative acceptable of this compound 20 with a reagent chosen between formic acid and its reactive derivatives, the reaction being followed, when necessary, by the elimination of the unwanted groups introduced by said reagent and / or the elimination of all protecting groups present.

t 17

Examples of suitable formic acid derivatives which can be used in process (A) above include orthoformates (e.g. triethyl orthoformate), dialkoxymethyl acetates (e.g. diethoxymethyl acetate), dithioformic acid, formamide, s-triazine or formamidine acetate.

Unwanted groups introduced by formic acid or a reactive derivative thereof can advantageously be 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, it also advantageously constitutes the solvent for the reaction. Other solvents which can be used include amides (eg dimethylformamide or dimethylacetamide), chlorinated hydrocarbons (eg dichloromethane), ethers (eg tetrahydrofuran) or nitriles (eg acetonitrile).

In some cases (for example when using a trialkyl orthoformate such as triethyl orthoformate), the reaction can advantageously be carried out in the presence of a catalyst such as a strong acid (for example concentrated hydrochloric acid , nitric acid or sulfuric acid). The reaction can be carried out at a temperature in the range of -25 "to +150 ° C, for example 0 to 100 ° C and preferably at room temperature.

In another process (B), compounds of formula (I) and their pharmaceutically acceptable derivatives or a protected form of these compounds are exposed to an interconversion reaction in which the substituent X initially present is replaced by a substituent X 35 different and / or the group Z initially present is replaced by a different group Z, the operation being followed, if necessary, by the elimination of all the protective groups present.

In one embodiment of method 5 (B), compounds of formula (I) in which X represents an RR1 group (where R and R1 are as defined above) can be prepared by amination of a compound correspondent of formula (I) in which X represents a halogen atom (for example chlorine). Amination can be carried out by reaction with an HNRR1 reagent (where R and R1 are as defined above), preferably in a solvent such as an alcohol (for example methanol). The reaction can be carried out at any suitable temperature and advantageously at an elevated temperature, for example at reflux or alternatively, when using liquid ammonia, in a sealed tube at a temperature of about 50 to 80 'VS. Conditions suitable for the conversion of halides to secondary and tertiary amines have also been described by I.T. Harrison et al in 20 Compendium of Oroanic Svnthetic Methods. Wiley-Inter-science, New York (1971), pages 250-252.

In another embodiment of process (B), compounds of formula (I) in which X represents an OR group (where R is as defined above) can be prepared by displacement of the atom d halogen (eg chlorine) with an appropriate RO ”anion. When R represents a hydrogen atom, the displacement reaction can be carried out by hydrolysis, which can be carried out in water or in a mixture of water and a water-miscible solvent such as an alcohol (e.g. methanol or ethanol), an ether (e.g. dioxane or tetrahydrofuran), a ketone (e.g. acetone), an amide (e.g. dimethylformamide) or a sulfoxide (e.g. dimethyl sulfoxide), advantageously in the presence of an acid or a base. Suitable acids include organic acids such as p-toluenesulfonic acid or inorganic acids such as hydrochloric acid, nitric acid or sulfuric acid. Suitable bases include inorganic bases such as alkali metal hydroxides or carbonates (e.g. sodium or potassium hydroxide or carbonate). An aqueous acid or an aqueous base can also be used as the reaction solvent. The hydrolysis can advantageously be carried out at a temperature in the range from -10 * to +150 * 0, for example at reflux. When R represents a C 4 alkyl or aryl group, the RO "anion is advantageously formed from a corresponding ROH alcohol using an inorganic base such as an alkali metal (for example metallic sodium) or a hydride of alkali metal (eg sodium hydride) The reaction with the anion formed in situ can conveniently be carried out at room temperature.

In another embodiment of process (B), compounds of formula (I) in which X represents an SH group can be prepared by reaction of the halogenated compound of formula (I) with thiourea in a solvent suitable such as an alcohol (eg n-propanol) at an elevated temperature (eg reflux), the reaction being followed by alkaline hydrolysis. Suitable bases which can be used include alkali metal hydroxides (eg sodium hydroxide). The reaction can advantageously be carried out according to the method of G.G. Urquart et al., Org. Syn. Coll. Flight. 3, 363 (1953), for example by refluxing the intermediate product with an aqueous NaOH solution for about 0.25 to about 5 hours.

In another form of implementation of the

process (B), compounds of formula (I) in which X

35 represents a hydrogen atom can be prepared by β 20 reduction of the halogenated compound of formula (I) using a reducing system which does not affect the rest of the molecule. Suitable reducing agents which can be used to drive the desired dehalogenation reaction include the metallic zinc / water system with which the method described by J.R. Marshall et al in J. Chem. Soc. 1004 (1951). Alternatively, the reaction can be carried out by photolysis in a suitable solvent such as tetrahydro-10 furan containing 10% triethylamine and, advantageously, in a Rayonet photochemical reactor (2537A) according to the method described by V. Nair and collaborators in J. Ora. Chem. 52, 1344 (1987).

According to yet another embodiment of method (B), compounds of formula (I) in which X represents a halogen atom can be prepared from a different halogenated compound of formula (I) by conventional halide exchange processes. Alternatively, when X is chlorine, this substituent may be replaced by other halogen atoms using various p- (halo) benzene-diazonium chlorides according to well known methods.

Compounds of formula (1) in which X represents an SR group where R is a C 4 -C 4 alkyl or aryl group can be prepared from the corresponding thiols using standard alkylation or arylation procedures, as described for example in United States Patent No. 4,383,114.

Compounds of formula (I) in which Z 30 represents a hydroxyl group can be conveniently prepared from a corresponding compound of formula (I) in which Z represents NH 2 by reaction with nitrous acid, using for example the mode procedure used by J. Davoll in J. Amer. Chem. Soc. 73, 3174 35 (1951).

V * "21

Many of the reactions described above have been widely described in connection with the synthesis of nucleosi-purine derivatives, for example in Nucleoside Analogs - Chemistry. Bioloov and Medical Applications.

5 published under the supervision of R.T. Walker et al., Plenum Press, New York (1979), pages 193-223, the subject of which is incorporated here for documentary purposes.

Pharmaceutically acceptable salts of the compounds of the invention can be prepared as described in U.S. Patent No. 4,383,114, incorporated herein for reference. Thus, for example, when it is desired to prepare an acid addition salt of a compound of formula (I), the product of any of the above processes can be converted to a salt by treatment of the resulting free base with a suitable acid, using conventional methods. Pharmaceutically acceptable acid addition salts can be prepared by reaction of the free base with a suitable acid, optionally in the presence of a suitable solvent such as an ester (e.g. ethyl acetate) or a alcohol (for example methanol, ethanol or isopropanol). Inorganic basic salts can be prepared by reacting the free base with a suitable base such as an alcoholate (eg sodium methylate), optionally in the presence of a solvent such as an alcohol (eg methanol) . Pharmaceutically acceptable salts can 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) can be converted into a phosphoric ester or another pharmaceutically acceptable ester by reaction with a phosphorylating agent such as POOC13 or with a suitable esterifying agent such as a halide or an acid anhydride, depending on the case.

> 22

An ester or a salt of a compound of formula (I) can be converted into the corresponding compound, for example by hydrolysis.

The compounds of formula (II) and their salts are new compounds and constitute another feature of the present invention.

The compounds of formula (II) in which Z represents hydrogen or a hydroxyl group can be prepared directly from the compound £ a NH2 ηοπλ1 • ·

! _I

• _ · 2a 10 by reaction with an excess of a pyrimidine of formula (III)

X

i NHo // \ / 2 ï · (III) A Λ

Z N V

(in which Y is a halogen atom such as chlorine and Z is hydrogen or a hydroxyl group) in the presence of an amino base such as triethylamine and in an alcoholic solvent (for example n-butanol) , advantageously at reflux.

Compounds of formula (II) in which Z represents NH2 can be prepared using the compound of formula 2a by reaction with an excess of a pyrimidine of formula (IV) 23

X

i / Λ N · I “(iv) A Λ

H2N N Y

(in which Y is as defined in formula (III) above under conditions similar to those which have just been described above for the preparation of compounds of formula (II) in which Z represents hydrogen or a hydroxyl group to form a compound of formula (V)

X

i

/AT

N · \ ί h / V \ h (V) ho-ch2x 7 · χ • ·

! I

• _ * i which can be diazotized using a diazonium salt ArN2 + E ~ (where Ar represents an aromatic group, for example p-chlorophenyl, and E “represents an anion, for example a halide anion such as chloride) in a solvent such as water, an organic acid such as acetic acid or their mixture, advantageously at a temperature of the order of room temperature to form a compound of formula (VI)

X

1 N = N-Ar // \ / N ·! “Λ Λ H2N N NH (VI) h ° -ch2 \ 7 · χ 1_; 24 (in which Ar has the definition which has just been given thereof) which can be converted into the desired compound of formula (II) by reduction using for example a reducing metal such as zinc in the presence of an acid, for example 5 example acetic acid. It should be noted that the choice of reducing agent depends on the nature of group X.

Compound £ a can be prepared from la-acetylamino-3a-acetoxy-methylcyclopent-2-ene (la), a precursor endowed with flexibility of use, by hydrolysis in the presence of a soft base such as a hydroxide of alkaline earth metal.

A particularly convenient synthesis of compounds of formula (I) via 6-chlorinated compounds of formula (II) is illustrated below.

25

Cl i NH.,

// \ / 1 N

I II

Λ \ Λ

Z N NH

NHAc ψ2

AcO — j · HO— ”· HO - —i · / \ / \ v \ il 1. · · - »_i -? 1 .-- '· .—. · - · the 2a? P 1

. ._. . NH9R

// \ './/X/ u // X / \ ΐ ΐ ΐ ΐ <> / \ / ’’ / \ / \ /' \\ / '\ /

H2N N \ -J- h / N \ -> 1 h N

HO—, · / \ / X

l / x, 11 î 1_ * = · · - * 6a (I) 58 Λ Î1 // \

NOT

I "/ \ / \ H, N N \

2 NH

H0 -] / \ i_ "4a 26

Compound 2a and the compounds of formulas (V) and (VI) are new intermediate compounds and constitute other particularities of the present invention. Compound 1a is a known compound described in U.S. Patent No. 4,138,562.

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

The splitting of the final product or of an intermediate compound or of the corresponding starting material can be carried out by any suitable process known in practice: see for example "Stereochemistry of 15 Carbon Compounds", EL Eliel (McGraw Hill, 1962) and "Tables of Resolving Agents", SH Wilen.

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

Other details of the invention are apparent from the detailed examples below in which the elemental analyzes were performed by M-H-W, Laboratories of Phoenix, AZ. The melting points were determined on a Mel-Temp device and were corrected. The nuclear magnetic resonance spectra were recorded in DMSO-Dg on Jeol FX 90QFT or Nicollet NT300 spectrometers. The chemical derivatives are expressed in ppm compared to the tetramethylsilane used as a reference substance. The infrared spectra were determined on KBr pellets with a Nicollet 50XC FT-35 IR spectrometer and the ultraviolet spectra were determined on a Beckmann DU-8 spectrophotometer. Mass spectra were recorded using an MS-30 mass spectrometer from AEI Scientific Apparatus Limited. Thin layer chromatography (TLC) was performed on 0.25 mm layers of Merck silica gel (particles 37-62 Mm).

All chemicals and solvents are of analytical quality unless otherwise specified. The term "active ingredient" used in the Examples denotes a compound of formula (I) or a pharmaceutically acceptable derivative of this compound.

Example 1 (±) - (la. 4a) -4- Γ (5-Amino-6-chloro-4-pvrimidinvlïamino1-2-cvclopenténvlcarbinol (3aï

A mixture of la-acetylamino-3a-acetoxymethyl-15 cyclopent-2-ene (la) (3.0 g, 15 mmol) and aqueous barium hydroxide (0.5 N, 300 ml) was heated to reflux overnight. After cooling, it was neutralized with dry ice. The precipitate was separated by filtration and the aqueous solution was concentrated to 20 sec. The residue was extracted with absolute ethanol and reconcentrated to give compound 2a as a colorless syrup, 1.6 g (14 mmol).

To this syrup were 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 on silica gel (7 g), conditioned in a flash chromatography column (4.0 x 12 cm) and eluted with a mixture of chloroform and methanol (20 : 1) giving 2.69 g (74%) of compound 3a melting at 130-132eC. An analytical sample was obtained by recrystallization from ethyl acetate (EtOAc), melting point 134-135 ° C, mass spectrum (30 ev, 200 ° C): m / e 240 and 242 (M + and M * +2) 209 35 (M + -31), 144 (B +); infrared spectrum: 3600-2600 (OH), 28 1620, 1580 (OC, ON); analysis (C10H13C1N40) C, H, N. Example 2 (± 1 - (Ια. 4a ^ -4-Γ (2-Amino-e-chloro-4-Pvrimidinvl) amino) -2-cvclopenténvlcarbinol f4aï 5 Added to 14 ml of crude product 2a (Example 1) of 2-amino-4,6-dichloropyrimidine (3.74 g, 22.8 mmol), triethylamine (15 ml) and n-butanol (75 ml) and the mixture was heated at reflux for 48 hours, the volatile solvents were removed, the residue was treated with methanol to separate the undissolved byproduct (double pyrimidine nucleoside). The methanolic solution was absorbed on silica gel (8 g), conditioned in a column (4.0 x 14 cm) and eluted with a mixture of chloroform and methanol (40: 1) giving 15 1.52 g (42%) of crude product 4a The product was recrystallized from ethyl acetate to give compound 4a; melting point 132-134eC, mass spectrum (30 ev, 200 ° C): m / e 240 and 242 (M + and M + + 2), 209 (M + -31), 144 (B +); infrared spectrum: 3600-3000 (NH2, OH), 20 1620, 1580 (C = C, C = N); anal. (C10H13C1N4) C, H, N.

Example 3 (±) - (la. 4a) -4— (Γ (2-Amino-6-chloro-5- (4-chlorophenylïzo) -4-pvrimidinvl-amino) -2-cvclopenténvlcarbinol (5a)

A cold solution of diazonium salt was prepared from p-chloraniline (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 compound 4a (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 * 29

yellow precipitate was filtered and washed with cold water until neutral, then it was air dried in the hood giving 3.60 g (94%) of compound Sâ, melting at 229 ° C.

(decomposition). The analytical sample was obtained from a mixture of acetone and methanol (1: 2), melting point 241-243 ° C (decomposition). Mass spectrum (30 ev, 260 ° C): m / e 378 and 380 (Μ + and M + +2), 282 (B +); infrared spectrum: 3600-3000 (NH2, OH), 1620, 1580 (C = C, C = N); analysis (C16H16C12N60) C, H, N.

10 Example 4 f ±) - (Ια. 4a) -4-Γ (2,5-Diamino-6-chloro-4-pvrimidinvl) aminol- 2-cvclopentenylcarbinol (6a)

A mixture of compound 5a (379 mg, 1 mmol), zinc powder (0.65 g, 10 mmol), acetic acid (0.32 ml), water (15 ml) and ethanol (15 ml) was heated at reflux under nitrogen for 3 hours. The zinc was removed and the solvents were evaporated. The residue was absorbed on silica gel (2 g), conditioned in a column (2.0 x 18 cm) and eluted with a CHCl3-MeOH 20 mixture (15: 1). We got a pink syrup. Further purification in a mixture of methanol and ether gave compound 6a as pink crystals, 170 mg (66%), melting point 168-170 ° C, mass spectrum (30 ev, 220eC) : m / e 255 and 257 (MT * and M + +2) 224 (M + -31) 159 25 (B +); infrared spectrum: 3600-3000 (NH2, OH) 1620, 1580

(C = C, C = N); anal. (C10H14C1N5) C, H, N

Example 5 f ±) - (la, 4a) -4- (6-Chloro-9H-purine-9-yl) -2-cyclopenténvl-carbinol (7a) 30 A mixture of compound 3a (1.30 g, 5, 4 mmol), triethyl orthoformate (30 ml) and hydrochloric acid (12N, 0.50 ml) was stirred overnight at room temperature. The solvent was evaporated at 35 ° C under vacuum. An aqueous solution of hydrochloric acid (0.5 N, 30 ml) was added to the residue and the mixture was stirred for 1 hour, neutralized & pH 7-8 with sodium hydroxide 1 N and was fixed by absorption on silica gel (8 g), conditioned in a column (4.0 x 8 cm) and eluted with a mixture of chloroform and methanol ( 20: 1), which gave white crystals of compound 7a, 1.12 g (82%). The crude product was recrystallized from ethyl acetate, giving compound 7a, melting at 108-110 ° C, mass spectrum (30 ev, 200 ° C): m / e 250 and 252 (M + and M + + 2), 219 (M + -31), 154 (B +); infrared spectrum: 3600-2800 (OH), 1600 (C = C, 15 C = N); anal. (¾¾ ^ 1 ^ 0) C, H, N.

Example 6 f ±) - (la. 4a) -4- {6-Hvdroxy-9H-purine-9-ylï -2-cvclopenténvl-carbinol (8a ^

A mixture of compound 7a (251 mg, 1 mmol) and aqueous sodium hydroxide (0.2 N, 10 ml) was heated at reflux for 3 hours. After cooling, the pH of the reaction mixture was adjusted to 5-6 with acetic acid. The reaction mixture was absorbed on silica gel (2 g), conditioned in a column (2.0 x 11 cm) and eluted with a mixture of CHCl3 and MeOH (10: 1), giving 105 mg ( 45%) of compound 8a · The crude white product was recrystallized from a mixture of water and methanol (3: 1) giving compound 8a melting at 248-2500 C (decomposition), mass spectrum (30 bp, 30,300 ° C): m / e 232 (M +), 214 (M + -18), 136 (B +); infrared spectrum: 3600-2600 (OH), 1680, 1600 (C = 0, C = C, C = N); anal. (£ 11 ^ 22 ^ 4 ^ 2) C, H, N.

31

Example 7 (±) - (la. 4a) -4- (6-Amino-9H-purine-9-v_ll-2-cvclopenténvl-carbinol (9ά)

Liquid ammonia was transferred to a bomb containing a solution of compound 7a (250 mgf 1 mmol) in methanol (5 ml) at -80 ° C. The bomb was closed and heated at 60 ° C for 24 hours. Ammonia and methanol were evaporated and the residue was recrystallized from water to give slightly dirty white crystals of compound 9a, 187 mg (81%), melting point 198-200 * 0. Mass spectrum (30 ev, 210eC); m / e 231 (M +), 213 (M * -18), 135 (B +); infrared spectrum: 3600-2600 (NH2, OH), 1700, 1600 (C = C, C = N); anal. (Cj ^ H ^ CsO) C, H, N.

15 F. VATnnl a R

(± \ - (la. 4a) -4- (6-Mercapto-9H-Purine-9-vl) -2-cvclopenténvl-carbinol flOa ^

A mixture of compound 7a (125 mg, 0.5 mmol), thiourea (40 mg, 0.64 mmol) and n-propanol (5 ml) was heated at reflux for 2 hours. After cooling, the precipitate was isolated by filtration, washed with n-propanol and dissolved in sodium hydroxide (1 N, 5 ml). The pH of the solution was adjusted to 5 with acetic acid. The crude compound 10a (90 mg, 73%) was isolated again, melting point 260-262 * 0 (decomposition), and was recrystallized from N, N-dimethylfor-mamide to give compound 10a. melting point 263-265 * 0 (decomposition). Mass spectrum (30 ev, 290 ° C): m / e 248 (MT * -), 230 (If * · -18), 152 (B +)? infrared spectrum: 3600-30 3200 (OH), 3100, 2400 (SH), 1600 (C = C, C = N); anal. (c11h12n40S> c / H / N32

Example 9 (t1-flo: .4a1 -4- (2-Amino-6-chloro-9H-purine-9-yl1 -2-cyclopen-tenvl-carbinol f! 3a)

A mixture of compound 6a (1.41 g, 5.5 mmol), 5% triethyl orthoformate (30 ml) and hydrochloric acid (12N, 1.40 ml) was stirred overnight. The suspension was dried in vacuo. Diluted hydrochloric acid (0.5 N, 40 ml) was added and the mixture was kept in reaction for 1 hour at room temperature. The mixture was neutralized to pH 8 with 1 N sodium hydroxide and absorbed on silica gel (7.5 g) conditioned in a column (4.0 x 10 cm) and it was eluted with a mixture of chloroform and methanol (20: 1) to give slightly dirty white crystals of compound 13a, 1.18 g (80%). The crude product was recrystallized from ethanol to give compound 13a. melting point 145-147eC. Mass spectrum (30 ev, 220 ° C): m / e 265 and 267 (M + and M + +2), 235 (M + -30), 169 (B +); infrared spectrum: 3600-2600 (NH2, OH), 1620-1580 (C = C, C = N); anal. (C11H12N5OCl.3 / 4 H20) C, H, N.

Example 10 (± 1- (1α.4α) -4- (2-Amino-6-hvdroxv-9H-Purine-9-vll-2-cvclopenténvlcarbinol (14al

A mixture of compound 13a (266 mg, 1 mmol) and aqueous sodium hydroxide (0.33 N) was heated at reflux for 5 hours, absorbed on silica gel (2 g), packed in a column (2.0 x 7.5 cm) and eluted with a mixture of chloroform and methanol (5: 1). The crude product was recrystallized from a mixture of methanol and water (1: 4) to give white crystals of compound 14a. 152 mg (61%), melting point 254-256eC

(decomposition). Mass spectrum (30 ev, 200 ° C): m / e 247 (H *), 217 (M * -30), 151 (B +); infrared spectrum: 33 3600-2600 (NH2, OH), 1700, 1600 (C = 0, C = C, C = N); anal.

(ChHi3N502.3 / 4 H20) C, H, N.

Example 11 - (la, 4al -4- f 2.6-Diamino-9H-Purine-9_rvl) -2-cvclopenténvl-5 carbinol fl5a)

Liquid ammonia was transferred to a solution of compound 13a (265 mg, 1 mmol) in methanol (10 ml) at -80 ° C in a bomb. The bomb was closed and heated to 75 ° C for 48 hours. The ammonia and methanol were evaporated. The residue was absorbed on silica gel (2 g), conditioned in a column (2.0 x 10 cm) and was eluted with a mixture of chloroform and methanol (15: 1). The crude product was recrystallized from ethanol to give 196 mg (80%) of compound 15a, melting at 152-155 ° C. Mass spectrum (30 ev, 200 ° C): m / e 246 (M +), 229 (M + -17), 216 (M + -30), 150 (B +); infrared spectrum: 3600-3000 (NH2, OH), 1700, 1650, 1600 (C = 0, C = C, C = N); anal. (C ^ H ^ NgO) C, H, N.

Tbremple 12 20 (! S, 4R) -4-f2.6-Diamino-9H-Purine-9-vl) -2-cvclopenténvl- carbinol [(1S, 4R) -4- (2,6-Diamino-9H- purine-9-yl) -2-cyclopentene-methanol] (a) Intermediate compound 1: Du (1R, 2S, 3R, 5R) -3- [6-Amino-25 9H-purine-9-yl] -5- [((1,1-dimethylethyl) dimethylsilyloxy) -methyl 1] -1,2-cyclopentanediol (-) Aristeromycin1 (12.505 g), tert-butyldimethylsilyl chloride (7.8 g) and imidazole (12, 96 g) in anhydrous dimethylformamide (85 ml) were 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 a salt solution (50 ml) before a white solid material separates by crystallization. This solid was collected by filtration, washed with ethyl acetate and then dried in vacuo to give the title product (3.92 g); proton magnetic resonance (DHSO-dg) 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 ^ d 2.09 (1H), 1.79 (1H), 0.89 (9H), 0.07 (6H).

10 1 Journal of the American Chemical society 1983, vol. 105, 4049-4055.

(b) Intermediate compound 2: (4R, 3aS, 6R, 6aR) -4- [6-Amino-9H-purine-9-yl] -6- [((1,1-dimethylethyl) dimethylsilyloxy) -methyl] - 3a, 5,6,6a-tetrahydro-4H-cyclopenta-1,3-dioxole-2-15 thione

A stirred suspension of Intermediate Compound 1 (3.45 g) in anhydrous dimethylforraamide (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 the solution from a previous test (on a 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 a salt solution (2 x 20 ml), dried (MgSC 4) and evaporated to give a yellow solid. This solid was washed with diethyl ether (25 ml) then collected by filtration, further washed with ether (25 ml) then dried in vacuo giving the title product as a solid pale cream in color (3.61 g); A max (ethanol) 240.0 nm (E * * m459) 'proton magnetic resonance (DMSO-dg) 8.27 (1H), 8.13 35 (1H), 7.33 (2H), 5.81 (1H), 5.37 (1H), 5.28 (1H), 3.78 (2H), 2.60 (1H), 2.28 (2H), 0.90 (9H), 0.09 ( 6H).

(c) Intermediate Compound 3; (l'R, 4'S) -9- [4 - (((1,1- 35

Dimethy1ethyl) dimethy 1 s ily loxy) methy1) -2 -cyclopentene-1-yl] -9H-purine-6-amine

A solution of Intermediate Compound 2 (3.57 g) in anhydrous tetrahydrofuran (25 ml) was treated with a solution of 1,3-dimethyl-2-phenyl-1,3,2-diazaphospholidine (4.94 g ) in anhydrous tetrahydrofuran (10 ml) then stirred at room temperature. for 8.75 hours. The solvent was removed by evaporation. The residual oil was combined with that which came from a previous test (on a 40% scale) then it was subjected to chromatography on a silica column (200 g, Merck 7734), eluted with chloroform then with mixtures of chloroform and ethanol to give a white solid. This solid was washed with diethyl ether (25 ml) and then collected by filtration. The solid substance was further washed with ether (10 ml) then dried, under vacuum, giving the product 2Q of ..... title (1.47 g); Xmax (ethanol) 261.4 nm (E * 443); proton magnetic resonance (DMSO-dg), 8.14 (1H), 8.00 (1H), 7.20 (2H), 6.12 (1H), 5.95 (1H), 5.60 (1H ), 3.66 (2H), 2.96 (1H), 2.69 (1H), 1.65 (1H), 0.74 (9H), 0.02 (6H).

(D) Intermediate compound 4: 1 (1'R, 4'S) -9- [4- (((1,1-dimethylethyl) dimethylsilyloxy) methyl) -2-cyclopen-tene-1-yl oxide] - 9H-purine-6-amine

A solution of Intermediate Compound 3 (1.37 g) in chloroform (30 ml) was treated with 80-90% m-chloroperoxybenzoic acid (1.29 g) and then stirred at room temperature for 3 hours. The solvent was removed by evaporation and the residual gum was dissolved in ethyl acetate (10 ml). A white solid separated by crystallization.

* 35 This solid substance and the material collected by evaporation of the filtrate were dissolved in chloroform (100 ml), then the solution was washed with a saturated aqueous solution of sodium bicarbonate (3 x 10 ml) and a solution of salt (2 x 10 ml). The aqueous wash liquors were reextracted with chloroform (50 ml). The combined organic solutions 5 were dried (MgSO 4) and then evaporated until a solid material was obtained. This solid material was washed with diethyl ether (25 ml) and then collected by filtration. The white solid was further washed with ether (10 ml) then dried under vacuum to give the title product (1.16 g)? Amax (ethanol) 235.4 nm (E * 1324), 263.2 nm (E?% 248), 300.2 nm (eJ% 75); proton magnetic resonance (CDC13) 8.72 (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 (6H).

(e) Intermediate Compound 5: (1'R, 4'S) hydrobromide -7-20 [4 - (((1,1-dimethylethyl) dimethylsilyloxy) methyl) -2-cyclopentene-1-yl] -2-imino- 1,2-dihydro [1,2,4] oxadiazolo- [3,2-i] -9H-purine

An ice-cold stirred suspension of Intermediate Compound 4 (1.08 g) in methanol (20 ml) was treated with a solution of cyanogen bromide (0.34 g) in methanol (20 ml ) added in 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. The residue was washed with diethyl ether (25 ml) and then collected by filtration. The solid material was further washed with ether (25 ml) and then dried under vacuum, giving the title product (1.37 g): Àmax (ethanol) 35 228.2 nm (E * 530), 285.2 nm (E * 445), · proton magnetic resonance (CDC13) 10.20 (1H), 10.02 (1H), 8.37 (1H), 6.25 (1H), 6.01 (1H), 5.90 (1H), 3.69 (2H), 3.05 (1H), 2.86 (1H), 1.73 (1H), 0.86 (9H), 0.03 (6H).

40 (f) Intermediate compound 6: (l'R, 4'S) -9- [4 - (((1,1-

Dimethylethyl) dimethylsilyloxy) methyl) -2-cyclopentene-1-37 yl] -6-cyanimino-1,6-dihydro-1-methoxy-9H-purine

A solution of Intermediate Compound 5 (1.36 g) in dimethylformamide (10 ml) was stirred at room temperature and then treated with 5-triethylamine (1.2 ml). After 40 minutes, 11iodomethane (0.54 ml) was added to give a yellow solution. After 3.75 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 a salt solution (20 ml), dried (MgSO4) and evaporated until a solid material was obtained. This solid material was washed with diethyl ether (25 ml) and then collected by filtration. This white solid was further washed with ether (10 ml) and then dried under vacuum to give the title product (0.865 g); Amax (ethanol) 227.2 nm (E ^% 449), 287.0 nm (E? -% 544); proton magnetic resonance 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 Compound 7; (l'R, 4'S) -9- [4 - (((1,1-

Dimethylethyl) dimethylsilyloxy) methyl) -2-cyclopentene-1-25 yl] -6-methoxyamino-9H-purine-2-amine

A solution of Intermediate Compound 6 (802 mg) and 1,8-diazabicyclo [5,4,0] undec-7-ene (0.45 ml) in ethanol (80 ml) was stirred and heated to reflux. Heating was stopped after 9 hours and the solution was kept at room temperature overnight. The solvent was removed by evaporation. The residual oil was combined with that which came from a previous test (on a 4% scale) then the mixture was subjected to chromatography on a silica column (40 g, Merck 35 9385), eluted with chloroform and then mixtures of chloroform and ethanol, which gave a foam. This foam was triturated with diethyl ether (10 ml) 38 and the resulting solid was collected by filtration. The solid was further washed with ether (5 ml) and then dried under vacuum to give the title product \ 1% 5 (594 mg)? Amax (ethanol) 282.2 nm (E. 409)? proton magnetic resonance (DMS0-d6) 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 10 (6H).

(h) Intermediate Compound 8: (ls, 4R) -4- [2-Amino-6-methoxyamino-9H-purine-9-yl] -2-cyclopentene-methanol

A solution of Intermediate Compound 7 (356 mg) in tetrahydrofuran (35 ml) was stirred at room temperature and then treated with tetrabutylammonium fluoride (1.0 M solution in tetrahydrofuran, 1.4 ml). After 90 minutes, the reaction was stopped with water (1 ml) and then the solvents were removed by evaporation. The residual oil was subjected to chromatography on a silica column (20 g, Merck 7734), eluted with chloroform and then with mixtures of chloroform and ethanol, and the title product was thus obtained under the form of a solid substance (243 mg); 1% Amax (buffer at pH 6) 280.2 nm (E ^ cm 534); proton magnetic resonance (DMS0-d6) 9.75 (1H), 7.39 (1H), 6.52 (2H), 6.10 (1H), 5.84 (1H), 5.27 (1H) , 4.73 (1H), 3.40 (2H), 2.83 (1H), 2.55 (1H), 1.52 (1H).

30 (IS. 4R) -4- Γ2.6-Diamino-9H-Purine-9-vll-2-cvclopentènecar- binol

An ice-stirred solution of Intermediate Compound 8 (210 mg) in water (10 ml) and tetrahydrofuran (50 ml) was treated with aluminum amalgam [prepared from aluminum (237 mg) and 0.5% aqueous solution of mercuric chloride), added in small amounts over 15 minutes. After 40 minutes, the mixture was allowed to stir to warm to room temperature. After 39 hours, the resulting mixture was filtered through Kieselguhr to remove insolubles. These materials were washed with a mixture of water and tetrahydrofuran (1: 5, 60 ml). The combined filtrates were evaporated. The residue 5 was subjected to chromatography on a silica column (10 g, Merck 9385), eluted with mixtures of chloroform and ethanol, which gave the title product in the form of a foam (159 mg )? [ot] D “81 * (ç 1.04, methanol); Amax (buffer at pH 6) 255.0 nm (E, 302), 280.8 nm 1% (El- 381), proton magnetic resonance (DMSO-d6) jl cm 15 7.61 (1H), 6, 66 (2H), 6.10 (1H), 5.87 (1H), 5.76 (2H), 5.38 (1H), 4.76 (1H), 3.45 (2H), 2.87 (1H), 2.60 (1H), 1.60 (1H).

Example 13 (1S. 4R ^ -4- (2-Amino-6-hvdroxy-9H-purine-9-vl) -2-cvclopen-20 tenvlcarbinol (11 R, 41 S) -2-Amino-1,9- dihydro-9- [4-hydroxymethyl-2-cyclopentene-1-yl] -6H-purine-6-one

A cloudy solution of the title compound of Example 12 (144 mg) in 0.1 M pH 6 buffer (10 ml) 25 (prepared from 28.4 g of disodium orthophosphate in 2 liters of water , adjusted to orthophosphoric acid) was treated with a solution of adenosine deaminase (0.5 ml, 778 units) in a 50% mixture of glycerol and 0.01 M potassium phosphate, at pH 6, 0, then stirred and heated to 37 °. After 18.5 hours, the resulting suspension was refrigerated. The collected solid was recrystallized from water to give the title product as a white solid (86 mg); [a] D -49 ° (ç, 0.5, dimethylsulfoxide); Amax 35 1% (pH 6 buffer) 252.6 nm (E. 531), proton X magnetic resonance (DMS0-d6) 10.60 (1H), 7.60 (1H), 6.47 (2H ), 6.10 (1H), 5.86 (1H), 5.33 (1H), 4.72 (1H), 3.45 (2H), 2.59 40 (1H), 1.58 (1H ).

* 40

Example 14

Preparation of enantiomers of ila.4a) -4-f2-amino-6-hvdroxv-9H-purine-9-vl) -2-cvclopenténvlcarbinol (a) (IS, 4R) -4 - (2 -Amino-6- hvdroxy-9H-Purine-9-yl) -2-5 cvclopenténvlcarbinol The diamino analog (100 mg) (Example 11) was dissolved in 3 ml of 0.05 M K2PO4 buffer (pH 7.4) while hot ( 50 ° C). The solution was allowed to cool to room temperature and 40 units of adenosine-10 daminase (Sigma, Type VI, calf intestinal mucosa) were added. After three days of incubation at room temperature, a precipitate formed which was collected by filtration; yield 18.2 mg. The filtrate was concentrated to a volume of 1.5 ml and refrigerated for 2 days. An additional amount of solid material was obtained by filtration in an amount of 26.8 mg. The two solid fractions were recrystallized from water giving the title product in the pure state, melting at 269-20 272 ° C, [a] p4 -62.1 ° (ç 0.3, MeOH).

(b) (IR, 4S) -4- (2-Amino-6-hvdroxv-9H-purine-9-yl) -2-cvclopenténvlcarbinol

The filtrates of the preparation of the 1S, 4R isomer (Example 14a) were combined and evaporated to dryness.

The unchanged diamine starting material was separated on a flash column packed with silica gel, using a 10% mixture of methanol and chloroform. The diamine compound was dissolved in 0.05 M K2PO4 buffer pH 7.4 (15 ml) and 800 units of adenosine deaminase were added. The solution was incubated for 96 hours at 37 ° C. Thin layer chromatography indicated that some unreacted product remained. The solution was heated in boiling water for 3 minutes and filtered to remove the denatured protein. Another 800 units of adenosine deaminase were added and the process was repeated. The protein-free solution was evaporated to dryness and the product was crystallized from water. The title product as a white solid was collected by filtration in water, mp 265-270e. [a] p4 +61.1 (ç 0.3, MeOH).

Example 15 (±) - (la.4tt) -4-f 2-Amino-6-hvdroxv-9H-purine-9-vl) -2-10 cvclopenténvlacétoxvcarbinol

Acetic anhydride (0.06 ml, 0.6 mmol) was added 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). The mixture was stirred at room temperature for 3 hours. Methanol (1 ml) was added to stop the reaction. The solution was concentrated and absorbed on silica gel (1.5 g) conditioned on a column (2.0 x 12 cm) and elution was carried out with a mixture of chloroform and methanol (20: 1). The product fractions were collected and concentrated to give a white solid. The solid product was washed with a mixture of methanol and ethyl acetate: yield 123 mg (85%). Further purification in methanol gave the title product as needle crystals melting at 237-239 ° C. Anal. (C13H15N503) C, H, N.

Example 16 (1S. 4RÏ -4) f 2-Amino-9H-Purine-9-yl ~) -2-cyclopenténYlcarbinol 30 An ice-stirred solution of (1S, 4R) -4- [2- amino-6-methoxyamino-9H-purine-9-yl] -2-cyclopentene-methanol (Intermediate Compound 8, Example 12) (1.202 g) in tetrahydrofuran (250 ml) and water (50 ml) was treated with alumi-nium amalgam (prepared from aluminum (1.761 g) and aqueous solution 42 of 0.5% mercuric chloride) added in small portions over 1 hour and 47 minutes. After 35 minutes, the mixture was allowed to stir to warm to room temperature. After 16 hours and 50 minutes, further aluminum amalgam (prepared 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 insolubles. The latter were washed with a mixture of tetrahydrofuran and water (5: 1, 300 ml). The combined filtrates were evaporated leaving a yellow foam. The foam was subjected to column chromatography on silica (33.8 g, Merck 7734) prepared in chloroform and eluted with mixtures of chloroform and ethanol to give several fractions (578 mg, 420 mg and 40 mg). The two largest fractions were crystallized separately from isopropanol. The filtrates were combined with the smallest fraction from the column and the mixture was subjected to preparative thin layer chromatography (Merck 5717) developed three times in a mixture of chloroform and methanol at 10: 1. The plates were eluted with ethyl acetate and with a mixture of ethyl acetate and ethanol (1: 1), to give a brown solid (45 mg). The solid was subjected to silica column chromatography (2.7 g, Merck 7734), prepared in chloroform and eluted with mixtures of chloroform, methanol and triethylamine, giving a gum (17 mg). After unsuccessful crystallization from isopropanol and charcoal treatment with methanol, an aqueous solution of the collected material was lyophilized to give the title compound (15 mg). Proton magnetic resonance (DMSO-dg) 1.62 (1H), 2.63 (1H), 2.89 (1H), 3.45 (2H), 4.73 (1H), 5.48 (1H) , 5.91 35 (1H), 6.14 (1H), 6.50 (2H), 7.98 (1H), 8.57 (1H). Spectrum "43 mass / [MH] + 232.

e 17

Formulations for Tablets A. The following formulation is prepared by wet granulation of the ingredients with a solution of povidone in water, drying and sieving, followed by addition of magnesium stearate and compression.

> ma / tablet 10 (a) Active ingredient 250 (b) Lactose BP 210 (c) Povidone BP 15 (d) Sodium salt of starch glycolate 20 (e) Magnesium stearate 5 15 _ 500 B. The following formulation by direct compression? lactose is of the direct compression type.

20 ma / tablet

Active ingredient 250

Lactose 145

Avicel 100

Magnesium stearate 5 25 _ 500 C. (Controlled release formulation) The formulation is prepared by wet granulation of the ingredients (below) with a solution of povidone in water, drying and sieving followed by addition. magnesium stearate * 44 and compression.

ai / tablet (a) Active ingredient 500 (b) Hydroxypropylmethylcellulose 5 (Methocel K4M, superior quality) 112 (c) Lactose B.P. 53 (d) Povidone B.P. 28 (e) Magnesium stearate 7 10 700

Example 18

Formulation for capsules

A capsule formulation is prepared by mixing the ingredients below and introducing the mixture into a two-part hard gelatin capsule.

ma / capsule

Active ingredient 125

Lactose 72.5

Avicel 50 20 Magnesium stearate 2.5 250

Example 19

Injection formulation 25 Active ingredient 0.200 g

0.1 M sodium hydroxide solution, sufficient quantity to adjust the pH to approximately 11 Sterilized water, sufficient quantity for 10 ml

The active ingredient is suspended in a small amount of water (which can be heated) and the pH is adjusted to about 11 with a solution of sodium hydroxide. The volume of water is then completed and filtered on a quality membrane for sterilization in a sterile 10 ml glass vial which is closed with sterile caps topped with capsules. y

Example 20

Suppository ma / suppository 10 Active ingredient (63 μπι) 250

Hard fat, B.P. 1770 2020

One fifth of the hard fat is melted in a steam jacket container at a maximum temperature of 45 ° C. The active ingredient is sieved through a 200 μιη sieve and added to the molten base by stirring, using a high shear agitator, until a homogeneous dispersion is obtained. By holding the mixture at 45 àC, add the remaining hard fat to the suspension and stir to obtain a homogeneous mixture. The entire suspension is passed through a 250 μπι stainless steel screen and, while continuing to agitate, it is allowed to cool to 40 ° C. Operating at 38 to 40 ° C, 2.02 g of the mixture is loaded into suitable 2 ml plastic molds. The suppositories are allowed to cool to room temperature.

Example 21 - ANTTVTRAT.E ACTIVITY 30 (A) HIV test

The compounds of formula (I) have been subjected to selective tests for determination of anti-HIV activity at the National Cancer Institute, Frederick Cancer Research “t 46

Facility, Frederick, Maryland (FCRF). The usual selective study procedures used by the FCRF are indicated below. The protocol is divided into three parts, (I) preparation of infected cells and distribution between 5 test plates, (II) preparation of drug dilution plates and distribution between test plates and (III) method XTT analysis. See D.A. Scudiero et al., "A New Simplified Tétrazolium Assay for Cell Growth and Drug Sensitivity in Culture", Cancer Res.

10 48, 4827 (1988).

I · Infection and distribution of ATH8 cells in microtiter trays

Cells to be infected (normal lymphoblastic cell line which expresses CD4) are placed in 50 ml conical centrifuge tubes and treated for 1 hour with 1-2 µg / ml polybrene at 37 ° C. The cells are then collected by centrifugation for 8 minutes at 1200 rpm. The HIV virus, diluted to one tenth in a medium (RMP1-1640, 10% human serum 20 or 15% fetal calf serum (FCS) added with IL-2 and antibiotic) is added in order to obtain an ME of 0.001. Only medium is added to the control cells not containing the virus. If an infectious virus titer of 10.4 is accepted, an MOI of 0.001 represents 8 infectious viral particles per 10,000 cells. About 500,000 cells per tube were exposed to 400 μΐ of the virus dilution. The resulting mixture is kept in incubation for 1 hour at 37 ° C. in a mixture of air and CO 2. Infected or uninfected cells are * 30 diluted so that there is 1 x 10 ”4 (with human serum) or 2 x 10” 4 (with fetal calf serum) cell per 100 μΐ.

Infected or uninfected cells (100 μΐ) are distributed between appropriate cells 35 of a microtiter plate comprising 96 cells, bottom i- ** 41 "47 in U. Each dilution of compound is tested in duplicate with cells infected. Uninfected cells are examined to assess drug sensitivity in a single cell for each dilution of the compound. The control cells without drug, infected and not ¢.

infected, are studied in triplicate. The cells 1 B2 to G2 serve as controls containing the reagents and receive only the medium. The plates are incubated at 37 ° C in a mixture of air and carbon dioxide until the time of addition of the drug.

II. Dilution and addition of the drug

Dilution plates (96-cell microtiter plates with flat bottom) are treated overnight with a phosphate buffered salt solution (PBS) or a medium containing at least 1% FCS or 1% human serum (depending on the medium used in the test), from the day before the test. This "blocking" method is used to limit drug adsorption by the microtiter plate during the dilution process.

The cells are completely filled with blocking solution and left to stand at room temperature in a humidified chamber, under a hood.

The dilution process is started by first diluting the test compound to 1:20. Blocked dilution plates are prepared by jerking off the blocking solution and drying by absorption on a sterile gauze pad. All the cells of each plate are then filled with 225 μΐ of the appropriate medium, using a Cetus liquid handling system. 25 μΐ of each compound diluted 1:20 is then added by hand in row A of a blocked and loaded dilution plate. Four compounds are added per dilution plate, which is sufficient to feed two test plates. The four compounds are then diluted serially by a factor of 10 from row A to row H using a Cetus system of "? * 4 48 handling of liquid. The starting dilution of each compound in row A is, at this stage, equal to 1: 200.

The dilution plates are kept on ice until ready to use.

5 Using a multi-channel pipetting apparatus with 6 microtips, 100 μΐ of each v dilution of drug are transferred to the test plate which already contains 100 μΐ of medium supplemented with cells. The final dilution in the test plate begins at 1: 400 (cells B4 to 10 G4). This dilution (up to 0.25% DMS0) prevents DMSO used as a vehicle from interfering with cell growth. Infected or uninfected cells devoid of drug (cells B3 to G3) and controls containing the reagents (B2 to G2) receive the medium alone.

The two final compounds are then transferred from cells H7 to H12 on a second test plate, according to the same procedure. The test plates are incubated at 37 ° C in a mixture of air and carbon dioxide for 7 to 14 days or until the virus-containing controls are lysed, by gross examination.

III. Quantitative expression of viral pathogenicity and drug activity A. Reagents 25 1. 2,3-bis [2-methoxy-4-nitro-5-sulfophenyl] -5- [(phenylamino) carbonyl hydroxide solution ] -2H-tetrazo-lium. (XTT) - 1 mg / ml solution in medium without FCS. Store at 4 ° C. Prepare every week. · "2. Stock solution of phenazine methosulfonate 30 (PMS) - It can be prepared and kept frozen at -20 ° C until use. It must be prepared in phosphate buffered saline at a concentration of 15.3 mg / ml.

B. Tetrazolium test in an aicroculture (MTA) 35 1. Preparation of the XTT-PMS solution - 11%. The XTT-PMS solution is prepared immediately before its addition to the cells of the culture dish. The PMS stock solution is diluted 1: 100 (0.153 mg / ml). Diluted PMS is added to each milliliter of XTT necessary to reach a final PMS concentration of 0.02 mM. A 1 aliquot of 50 μΐ of the XTT-PMS mixture is added to each of the appropriate cells and the plate is incubated for 4 hours at 37 ° C. The plate covers are removed and replaced with adhesive plugs (Dynatech 10 cat 001-010-3501). The closed plate is shaken on a mixer for microculture plates and the absorption is determined at 450 nm.

IV. Results

The single figure is a graphical representation of the change in the percentage of test cells compared to uninfected cells (%) for infected and uninfected cells, as a function of the increase in concentration of the compound of Example 10 .

The results represented graphically on the '20 single figure allow the calculation of an effective concentration (EC50) compared to infected cells of approximately 0.15 Mg / ml, of an inhibitory concentration (IC50) compared to cells normal values of approximately 100 Mg / ml and a therapeutic index (IT50) of approximately 25,667. A trial previously carried out at Southern Research

Institute gave an IT50 of around 200 when MT-2 cells were grown in the presence of H9 / HTLV-1 IIIB. >

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

* 50 TABLE 1

Cctrpose Exeqple Line DE50 DI50 ΓΓ50 5 cell Λ - ___ -r? 9a 7 ΜΓ-2 2.3 50 21.4 ”13a 9 ΜΓ-2 0.41 6.97 17.3 14a 10 ΜΓ-2 0.15 100 667 10 15a 11 ΜΓ-2 2.9> 125> 42 , 7 (-) 14a 14 (b) EMC 0.66 189 284

The compounds of Examples 5 and 8 also showed antiviral activity in this selective study.

(B) Activity against the cat leukemia virus

A selective study of antiviral activity against the FeLV-FAIDS virus was carried out in 96-cell plates (Corning) using 81-dicatrix cells 81C in Dulbecco medium modified according to Iscove, supplemented with 10% fetal serum heat-inactivated bovine (FBS). Twenty hours before the test, the plates were inoculated with 81C cells at a rate of 5 × 10 3 cells per cell. The day of the test, the 25 cells were previously treated for 30 minutes at 37 ° C. with DEAE-dextran (25 μg / ml) in 0.1 ml of balanced Hanks salt solution. This solution was removed, then 0.1 ml of growth medium containing 32 TCID50 of FeLV-FAIDS or 0.1 ml of growth medium alone was added to each cell. The virus was allowed an absorption time of 1 hour and then 0.1 ml of test compound or control compound - positive (2 ', 3' -dideoxycytidine? DdC) or growth medium was added. . The plates were incubated at 37’C. The cells were added with fresh growth medium containing the compound on the fourth day after infection.

The culture medium was completely changed and replaced with fresh medium containing the compound on the seventh day 15.51 after infection. On the tenth day after infection, the cells were fixed with formalin, stained with Coomassie R-250 0.1% brilliant blue and examined under a microscope to determine the cytopathic effect and the cytotoxicity of the drug. . ^

The compound of Example 10 exhibited an ED50 dose of 1.9 Mg / ml.

(C) Activity against mouse AIDS virus

Falcon 6-cell tissue culture plates were seeded with 1.75 x 105 cells per cell in a total volume of 2.5 ml of EMEM containing 5% heat inactivated FBS. Twenty hours after the cell seeding, the medium was separated by decantation and 2.5 ml of DEAE-dextran (25 μg / ml in a phosphate buffered salt solution) were added to each cell. Cultures were incubated at 37 ° C for 1 hour, after which the DEAE-dextran cell was separated by decantation and the cell layers were rinsed once with 2.5 ml PBS. Controls formed from normal cells were prepared with 2.5 ml of medium alone (virus and drug free). Control cultures containing the drug received 2.5 ml of medium containing the drug but not containing virus. Control cultures infected with the virus received 0.5 ml of the appropriate dilution of CAS-BR-M stock solution to produce countable plates, plus 2.0 ml of medium. Test samples received 0.5 ml of the appropriate virus dilution plus 2.0 ml of drug dilution medium. Six concentrations of the test compound were tested in a series of 10 semi-log dilutions. Three concentrations of the ddC positive control drug were tested. Each trial included three cells for each concentration of test compound and six virus infected cultures and six cell control cultures. On the third day after inoculation of t 5 τ 52 * "s virus, the toxicity of the drug to SC-1 cells was determined by microscopic examination of a colored control culture in duplicate containing the cells and the drug. The remaining test cultures and control cultures were irradiated with an ultraviolet lamp for 20 seconds and XC cells were added to each culture (5 x 105 cells / cell in 2.5 ml of EMEM medium containing 10% heat-inactivated FBS). On the third day after irradiation with ultraviolet rays, the cultures were fixed with formalin and stained with crystal violet. The plates were counted using a dissecting microscope.

The antiviral activity in reducing CAS-BR-M plaques was expressed in terms of reduction in the average number of plaques counted in virus-infected cultures treated with the drug compared to the average number of plaques counted in untreated control cultures infected with the virus (percent compared to the control). The compound of Example 20 had an ED50 dose of 1.1 µg / ml.

(D) Activity against the simian retrovirus SAIDS (SRV-2Ï

A selective antiviral study against the SAIDS virus (D / Washington) was carried out according to a syncytial inhibition test involving Raji cells. The drug was diluted in complete Isvove medium and then 100 ml of each dilution was added to the appropriate wells of a 96 well plate. Raji cells in * active growth phase, in an amount of 5 × 10 · * cells * in 50 μΐ of complete Iscove medium, were then added to each alveolus. This operation was followed by the addition of 50 μΐ of clarified supernatant liquor originating from a co-culture of SRV-2 / Raji cells. DdC was included in this trial as a positive control drug.

Plates were incubated at 37 eC in a humidified atmosphere containing 5% co2. Syncytial cells

T J

AT

% 53 were counted on the seventh day after infection. The toxicity of the drug was evaluated by comparing the numbers of viable cells in the uninfected sample treated with the drug to the viability of the untreated and uninfected control. The compound of Example 10 showed an ED50 value of 2.8 μg / ml. (E) Activity against Visna Maedi virus The antiviral activity against the WLC-1 strain of Visna Maedi virus (VMV) was determined by measuring the reduction in the specific immunohistochemical staining of the virus. Monolayers of sheep choroid plexus cells were infected with the VMV virus and were coated with serial dilutions of the test compounds.

After incubation for five days, the monolayers were further incubated with virus specific antisera conjugated to Horseradish peroxidase (HRP).

The subsequent incubation of the monolayers with a chromogenic substrate of HRP colors areas of replication of the virus.

These discrete foci were counted and the concentration of test compound necessary to reduce the number of foci to 50% of that of the controls not treated with the drug was calculated.

The compound of Example 13 had an ED50 value of 0.2 μg / ml.

25 Example 22

CYTOTOXIC ACTIVITY

The compounds of Examples 5, 7 and 8 showed cytotoxic activity when tested against a culture of P388 mouse leukemia cells, as described by R.G. Alonquist and R. Vince in J. Med. Chem., 16, 1396 (1973). The ED50 values (μφ / ηΐ) obtained were as follows:

Example 5 12

Example 7 40 35 Example 8 3

T J

*

Claims (17)

1. Compound of formula (I) ï · 1 / \ Λ J Λ \ Λ / (η ZNM \ _f in which X is hydrogen, a group NRR1, SR, OR or a halogen; 5. is hydrogen, an OR2 or NRR1 group; R, R1 and R2 may be the same or different and are chosen from hydrogen, C 1 -C 4 alkyl and aryl groups and its pharmaceutically acceptable derivatives. 2. Compound according to claim 1, characterized in that Z represents H, OH or NH2 in formula (I). 3. Compound according to claim 1 or 2, characterized in that Z represents NH2. 4. Compound according to any one of claims 1 to 3, characterized in that X represents hydrogen, a chloro radical, an NH2, SH or oh group. at 5. Compound according to any one of Claims 1 to 4, characterized in that X represents 20 OH. 6. Compound according to any one of claims 1 to 4, characterized in that X represents H or NH2. 7. Le (la, 4a) -4- (6-chloro-9H-purine-9-yl) -2-cyclopentenylcarbinol; . ÎT J 4 Λ 55 η le (ία, 4α) -4- (6-hydroxy-9H-purine-9-y1) -2-cyclopentenylcarbinol? (Ια, 4α) -4- (6-amino-9H-purine-9-yl) -2-cyclopentenylcarbinol; 5 le (la, 4a) -4- (6-mercapto-9H-purine-9-yl) -2- j. cyclopentenylcarbinol; (ία, 4a) -4- (2,6-diamino-9H-purine-9-yl) -2-cyclopentenylcarbinol; (ία, 4a) -4- (2-amino-6-chloro-9H-purine-9-10 yl) -2-cyclopentenylcarbinol or le (la, 4a) -4 - (2-amino-9H-purine -9-yl) -2-cyclopentenylcarbinol according to claim 1. 8. The (Ια, 4a) -4- (2-amino-6-hydroxy-9H-purine-9-yl) -2-cyclopentenylcarbinol according to claim l. 9. Compound according to any one of claims 1 to 8, characterized in that it is mainly in the form of a racemic mixture. 10. Compound according to any one of claims 1 to 8, characterized in that it consists essentially of an optical isomer. 11. Compound according to any one of claims 1 to 8, characterized in that it is mainly composed of the D isomer. 12. A compound of formula (I) according to any one of claims 1 to 11 or a pharmaceutically acceptable derivative of this compound, for use as an active therapeutic agent. at 13. A compound of formula (I) as defined in * any one of claims 1 to 11 or a pharmaceutically acceptable derivative * 30 of this compound, intended for use in the preparation of a medicament for the treatment of a viral infection. 14. Pharmaceutical formulation, characterized in that it comprises a compound of formula (I) according to any one of claims 1 to 11 or a phar- * i 4 Μ 56 maceutically acceptable derivative of this compound in association with a support pharmaceutically acceptable suitable. 15. Pharmaceutical formulation, characterized in that it comprises a compound of formula (I) according to any one of claims 1 to 11 or a salt | pharmaceutically acceptable of this compound in combination * with an appropriate pharmaceutically acceptable carrier. 16. Pharmaceutical formulation according to claim 13, characterized in that it further comprises another therapeutic agent. 17. Compound of formula (II)} • NH, // w 2 N · zAY \ h / N [* \ _ y in which X represents hydrogen, a group NRR1, SR, OR, a halogen or their protected forms? Y represents OH or one of its protected forms; Z represents hydrogen, an OR2 group, NRR1 or one of their protected forms; R, R1 and R2 may be the same or different, and are selected from hydrogen and C1-4alkyl and aryl, or their pharmaceutically acceptable derivatives. , î K