WO1995007910A1 - Antiviral indole derivatives - Google Patents

Abstract

Compounds of formula (I), in which R?8 and R9¿, which may be the same or different, each together with the carbon atoms to which they are attached form an unsaturated 6-membered carbocyclic ring in which from 1 to 3 carbon atom(s) may be replaced by nitrogen atom(s), providing that at least one ring structure contains at least one nitrogen atom, and their use for the treatment or prophylaxis of viral infections.

Description

ANTIVIRAL INDOLE DERIVATIVES

The present invention relates to certain novel indole derivatives, salts, esters and physiologically functional derivatives thereof, to their use in medical therapy and in particular to their use in the manufacture of a medicament for the treatment or prophylaxis of viral infections, and to pharmaceutical formulations thereof.

Of the DNA viruses, those of the herpes group are the source of the most common viral illnesses in man. The group includes herpes simplex virus types 1 and 2 (HSV1) (HSV 2), varicella zoster virus (VZV), cytomegalovirus (CMV), Epstein-Barr virus (EBV) and Human Herpes Virus 6 (HHV6) and Human Herpes Virus 7 (HHV7). Most of these viruses are able to persist in the host's neural cells; once infected, individuals are at risk of recurrent clinical manifestations of infection which can be both physically and psychologically distressing.

HSV infection is often characterised by extensive and debilitating lesions of the skin, mouth and/or genitals. Primary infections may be subclinical although tend to be more severe than infections in individuals previously exposed to the virus. Ocular infection by HSV can lead to keratitis or cataracts thereby endangering the host's sight. Infection in the newborn, in immunocompromised patients including Acquired Immune Deficiency Syndrome (AIDS) patients or penetration of the infection into the central nervous system can prove fatal.

VZV is a herpes virus which causes chickenpox and shingles. Chickenpox is the primary disease produced in a host without immunity and in young children is usually a mild illness characterised by a vesicular rash and fever. Shingles or zoster is the recurrent form of the disease which occurs in adults who were previously infected with VZV. The clinical manifestions of shingles are characterised by neuralgia and a vesicular skin rash that is unilateral and dermatomal in distribution. Spread of inflammation may lead to paralysis or convulsions. Coma can occur if the meninges becomes affected. In immunodeficient patients VZV may disseminate causing serious or even fatal illness. VZV is of serious concern in patients receiving immunosuppressive drugs for transplant purposes or for treatment of malignant neoplasia and is a serious complication of AIDS patients due to their impaired immune system. In common with other herpes viruses, infection with CMV leads to a lifelong association of virus and host and, following a primary infection, virus may be shed for a number of years. Congenital infection following infection of the mother during pregnancy may give rise to clinical effects such as death or gross disease (microcephaly, hepatosplenomegaly, jaundice, mental retardation), retinitis leading to blindness or, in less severe forms, failure to thrive, and susceptibility to chest and ear infections. CMV infection in patients who are immunocompromised for example as a result of malignancy, treatment with immunosuppressive drugs following transplantation or infection with Human Immunodeficiency virus (HIV) may give rise to retinitis, pneumonitis, gastrointestinal disorders and neurological diseases.

The main disease caused by EBV is acute or chronic infectious mononucleosis (glandular fever). Examples of other EBV or EBV associated diseases include lymphoproliferative disease which frequently occurs in people with congenital or acquired cellular immune deficiency, X-linked lymphoproliferative disease which occurs mainly in young boys, EBV-associated B-cell tumours, Hodgkin's disease, nasopharyngeal carcinoma, Burkitt lymphoma, non-Hodgkin β-cell lymphoma, immunoblastic lymphoma, thymomas and oral hairy leukoplakia. EBV infections have also been found in association with a variety of epithelial-cell-derived tumours of the upper and a lowe respiratory tracts including the lung.

HHV-6 has been shown to be a causative agent of infantum subitum in children and of kidney rejection and interstitial pneumonia in kidney and bone marrow transplant patients respectively and may be associated with other diseases. There is also evidence of repression of stem cell counts in bone marrow transplant patients. HHV-7 is of undetermined disease aetiology.

Hepatitis B Virus (HBV) is a viral pathogen of world-wide major importance. The virus is aetiologically associated with primary hepatocellular carcinoma and is thought to cause 80% of the world's liver cancer. Clinical effects of infection with HBV range from headache, fever, malaise, nausea, vomiting, anorexia and abdominal pains. Replication of the virus is usually controlled by the immune response, with a course of recovery lasting weeks or months in humans, but infection may be more severe leading to persistent chronic liver disease as outlined above. Papillomaviruses are widespread in nature and infect most vertebrate species including humans. These viruses commonly induce a variety of benign squamous epithelial (warts and papillomas) and fibroepithelial (fibropapillomas) tumours. Over the past 10 years, the human papillomaviruses (HPVs) have been recognized as the aetiological agent responsible for venereally transmitted genital warts. In particular, exophytic genital warts or condyloma which occur on the penis, vulva or in the perianal region are highly associated with infection by HPV types 6 and 11. In addition, juvenile and adult onset laryngeal papillomas are associated with infection by HPV types 6 and 11. A papiHomvirus aetiology for cervical dysplasia and flat genital warts is derived from numerous studies which demonstrate the presence of HPV types 16 and 18 (and other related HPVs such as 31,33,35 and 39) in more than 85% of the primary tumours. Other HPV types are associated with a variety of benign cutaneous papillomas including palmar and plantar warts, common and flat warts which are associated primarily with HPV types 1 to 4.

Of the RNA viruses, one group has assumed a particular importance. These are the retroviruses. Retroviruses form a sub-group of RNA viruses which, in order to replicate, must first 'reverse transcribe' the RNA of their genome into DNA ('transcription' conventionally describes the synthesis of RNA from DNA). Once in the form of DNA, the viral genome may be incorporated into the host cell genome, allowing it to take advantage of the host cell's transcription/translation machinery for the purposes of replication. Once incorporated, the viral DNA is virtually indistinguishable from the host's DNA and, in this state, the virus may persist for the life of the cell.

A species of retrovirus, HIV 1 and 2, has been reproducibly isolated from humans with AIDS or with the symptoms that frequently precede AIDS. AIDS is an immunosuppressive or immunodestructive disease that predisposes subjects to fatal opportunistic infections. Characteristically, ADDS is associated with a progressive depletion of T-cells, especially the helper-inducer subset bearing the OKT surface marker. HIV is cytopathic and appears to preferentially infect and destroy T-cells bearing the OKT marker and it is now generally recognised that HIV is the aetiological agent of AIDS. Clinical effects of infection with HIV include AIDS and other related conditions such as AIDS-related complex (ARC), progressive generalised lymphadenopathy (PGL), Karposi's sarcoma, thrombocytopenic purpura, AIDS-related neurological conditions, such as multiple sclerosis or topical paraparesis, and also anti-HIV antibody-positive conditions, including such conditions in asymptomatic patients.

Another RNA virus which has been recognised as the causative agent of an increasingly serious international health problem is the non-A, non-B hepatitis. At least 80% of cases of chronic post-transfusional non-A, non-B hepatitis have been shown to be due to the virus now identified as hepatitis C and this virus probably accounts for virtually all cases of post-transfusional hepatitis in clinical settings where blood products are screened for hepatitis B.

Coxsackie viruses belong to the enterovirus genus. They have a single stranded RNA genome contained in an icosachedral nucleocapsid. Coxsackie virus infection is increasingly recognised as a cause of primary myocardial disease in adults and children. Coxsackie infection is also associated with meningitis, pleurodynia, herpangia, hand-feet and mouth disease, respiratory disease, eye disease, diabetes and post-viral fatigue syndrome. In the latter case viral RNA has been detected in the muscle and in menocytes.

European Patent Specification 0 328 000 describes certain indolecarbazole derivatives and indicates thafthese compounds can be used for the treatment of heart and blood vessel diseases, such as thrombosis, arteriosclerosis and hypertension, inflammatoiy processes, allergies, cancers and certain degenerative damage to the central nervous system. Maleimide derivatives having similar suggested properties are described in European Patent Specification 0 391 060.

US patent 5,043,335 describes certain indolecarbazole derivatives and their use in the treatment of heart and blood vessel diseases such as thrombosis, arteriosclerosis and hypertension.

PCT specification number 9300571 describes certain indolecarbazole derivatives and their use in the treatment or prophylaxis of viral infections.

We have now identified certain novel indole derivatives which have been found suitable for use in the treatment or prophylaxis of viral infections, for example retrovirus, herpes virus, hepatitis virus, influenza virus, papillomavirus, coxsackie virus and hepatitis C virus infections. In particular the compounds of the invention are used in the treatment or prophylaxis of CMV infections.

According to the present invention we provide the compounds of formula (I):

wherein R¹ represents:-

-H;

-COR¹⁰; CH₂OR¹⁰; CO₂R¹⁰; OR¹⁰ [where R¹⁰ is C_1-6 alkyl, C_3-7 cycloalkyl, aryl (for example phenyl), arylalkyl (for example benzyl), C_1-6 alkenyl, or H];

-NR¹¹R¹²; CH₂NR^{1 1}R¹² [where R¹¹ and R¹², which may be the same or different, each represent H, COR¹⁰ (where R¹⁰ is hereinbefore defined), C_1-6 alkyl, C_3-7 cycloalkyl, aryl, arylalkyl, or R¹¹ and R¹² together with the N atom to which they are attached form a 3-,4-,5- or 6- membered heterocyclic ring (for example piperidine, pyrrolidine) in which from 1 to 3 carbon atom(s) are replaced by hereroatom(s) independently selected from O, N and S (for example morpholino, piperazine) which ring may, where possible, be partially or completely unsaturated];

R² and R³, which may be the same or different, are each independently selected from:-

-H;

-OR¹⁰; COR¹⁰; CO₂R¹⁰ (where R¹⁰ is hereinbefore defined); -C_1-4alkyl, C_2-4alkenyl or C_3-8cycloalkyl where the alkyl, alkenyl or cycloalkyl moiety may be optionally substituted by one or more substituents selected from halogen, cyano, nitro, azido, COR¹⁰, CO₂R¹⁰, OCOR¹⁰, SOR¹⁰, CO₂NR¹¹R¹², C_3-8cycloalkyl, OR¹⁰, SR¹⁰, SO₂R¹⁰, NR^{1 1}R¹² (where R¹⁰, R¹¹ and R¹² are each as defined above);

[where T is NR¹⁰,S or O, Z is NH, S or O and W is NR¹¹R¹² (where R¹¹ and R¹² are each as hereinbefore defined)]; heterocycle; -N-heterocycle; heteroaryl or aryl optionally substituted by one or more substituents selected from OR¹⁰, NR¹¹R¹², SR¹⁰, SO₂R¹⁰, CO₂R¹⁰, nitro, cyano, SCN, C_1-6alkyl, C_3-6cycloalkyl, haloalkyl (for example trifluoromethyl), hydroxylalkyl, OCOR¹⁰, SOR¹⁰, CONR¹¹R¹², SO₂NR¹¹R¹², halogen and methylene dioxy (where R¹⁰, R^{1 1} and R¹² are each as defined above);

-NR^{1 1}R¹² (where R¹¹ and R¹² are each as defined above);

R⁶ and R⁷, which may be the same or different, each represents one or more ring substituent(s) selected from:-

-H;

-C_1-6alkyl optionally substituted by OR¹⁰ (where R¹⁰ is hereinbefore defined), halogen, (for example trifluoromethyl), or NR¹¹R¹² (where R¹¹ and R¹² are as defined above);

-cyano; nitro; halogen; methylene dioxy, OR¹⁰; SR¹⁰; SOR¹⁰; SO₂R¹⁰; CO₂R¹⁰; OCOR¹⁰ SO₂NR¹¹R¹²; NHSO₂R¹⁰; CONR¹¹R¹²; NHCOR¹⁰ and NR¹¹R¹² (where R¹⁰, R¹¹ and R¹² are as defined above);

R⁸ and R⁹, which may be the same or different, each together with the carbon atoms to which they are attached form an unsaturated 6-membered carbocyclic, preferably an aromatic, ring in which from 1 to 3 carbon atom(s) may be replaced by nitrogen atom(s), providing that at least one ring structure contains at least one nitrogen atom, which may optionally be substituted with an oxide group; R¹³ and R¹⁴ may together form a carbonyl group (>=O) or R¹³ is X and R¹⁴ is Y and both represent H, or X and Y are different and one of X or Y represents H and the other represents OR¹⁰ or SR¹⁰,(where R¹⁰ is as defined above), compounds where R¹³ and R¹⁴ form a carbonyl group are preferred; or a salt, ester or physiologically functional derivative thereof or a solvate of any thereof.

Preferred compounds of formula (I) include those wherein both R⁸ and R⁹ form a 6-membered aromatic ring in which one carbon atom is replaced by a nitrogen atom in each ring system and ideally each nitrogen atom of each ring system is in the 1 and 11 positions respectively and in which each of the nitrogen atoms may optionally be substituted with an oxide group.

Further preferred compounds of formula (I) include those wherein both R⁸ and R⁹ form a 6-membered aromatic ring in which only one ring system has one carbon atom replaced by a nitrogen atom ideally either in the 1 or 11 position respectively and in which the nitrogen atom may optionally be substituted with an oxide group .

Particularly preferred compounds of formula (I) include:

(i) 12H,13H-pyrido [3',2':4,5]pyrrolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7-dione;

(ii) 12H,13-(3-cyanopropyl)pyrido[3',2':4, 5]pyrrolo[2,3-a]pyrrolo[3,4-c]carbazole- 5,7-dione;

(iii) 12H,13-ethylpyrido[3',2':4,5]pyrrolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7-dione;

(iv) 12H,13-allylpyrido[3',2^,:4,5]pyrrolo[2,3-a]pyrrolo[3,4c]carbazole-5,7-dione;

(vi) 12H,13-(2,3-dihydroxypropyl)pyrido[3',2':4,5]pyrrolo[2,3-a]pyrrol[3,4-c]

carbazole-5,7-dione;

(vi) 12H,13H-9-chloropyrido[3',2':4,5]pyrrolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7- dione: (vii) 12H,13H-pyrido[3',2':4,5]pyrrolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7-dione-1- oxide; and

(viii) 12H,13-ethylpyrido[2,3-b]pyrrolo[3,4-c]pyrido[3',2':4,5]pyrrolo[3,2-g]indole- 5,7-dione.

As used herein, the term "alkyl" as a group or part of a group means a straight or branched chain alkyl group. Such alkyl groups preferably have 1 to 3 carbon atom(s). As used herein the term "aryl" as a group or part of a group includes phenyl and naphthyl. The term heteroaryl includes a 5- or 6-membered aromatic ring where 1 to 3 carbon atom(s) are replaced with heteroatom(s) selected from N, O or S (for example pyridyl, pyrrolyl, thienyl and furyl), optionally fused to an aryl ring (for example quinolyl, isoquinolyl, benzimidazolyl, benzotriazolyl, benzothienyl, benzoxazolyl, benzothiazolyl), and the term heterocycle includes a 5- or 6-membered carbocyclic ring where 1 to 3 carbon atom(s) are replaced by hetero atom(s) selected from N, O or S (for example morpholine, pyrrolidine, piperidine, piperazine) which may be partially or completely saturated.

The compounds of formula (I) described above and their salts, esters and physiologically functional derivatives and the solvates of any thereof are hereinafter referred to as the compounds according to the invention.

The present invention further includes: a) compounds according to the invention for use in medical therapy particularly in the treatment or prophylaxis of a viral infection (such as those set out herebefore) especially CMV infections; b) use of a compound according to the invention in the manufacture of a medicament for use in the treatment or prophylaxis of a viral infection (such as those set our herebefore); c) a method for the treatment of a viral infection (such as those set out herebefore) comprising administering to the subject an antivirally therapeutic amount of a compound of the invention; and d) pharmaceutical formulations comprising a compound of the invention and at least one pharmaceutically acceptable carrier or excipient.

Examples of clinical condition caused by viruses which may be treated in accordance with the invention include those referred to above.

As used herein, the term "physiologically functional derivative" means any physiologically acceptable salt, ester, or salt of such ester of a compound of formula (I) above or any other compound which upon administration to the recipient, is capable of providing (directly or indirectly) such a compound or an antivirally active metabolite or residue thereof.

In addition to the use of compounds of formula (I) in the treatment or prophylaxis of the above viral infections and associated conditions, the compounds may also be used for the treatment or prophylaxis of heart and blood vessel diseases, thrombosis, arteriosclerosis and hypertension, inflammatory processes, allergies, cancer and certain degenerative damage to the central nervous system.

Preferred esters in accordance with the invention include carboxylic acid esters in which the non-carbonyl moiety of the carboxylic acid portion of the ester grouping is selected from straight or branched chain alkyl (for example, methyl, n-propyl, t-butyl, or n-butyl), cycloalkyl, alkoxyalkyl (for example, methoxymethyl), aralkyl (for example, benzyl), aryloxyalkyl (for example, phenoxymethyl), aryl (for example, phenyl optionally substituted by, for example, halogen, C_1-4 alkyl, or C_{1- 4} alkoxy), or amino; sulphonate esters, such as alkyl- or aralkylsulphonyl (for example, methanesulphonyl); amino acid esters (for example, L-valyl or L-isoleucyl); and mono-, di-, or triphosphate esters. In such esters, unless otherwise specified, any alkyl moiety present advantageously contains from 1 to 18 carbon atoms, particularly from 1 to 6 carbon atoms, more particularly from 1 to 4 carbon atoms. Any cycloalkyl moiety present in such esters advantageously contains from 3 to 6 carbon atoms. Any aryl moiety present in such esters advantageously comprises a phenyl group. Any reference to any of the above compounds also includes a reference to a physiologically acceptable salt thereof.

Examples of physiologically acceptable salts of the compounds of formula (I) and physiologically acceptable derivatives thereof include salts derived from an appropriate base, such as an alkali metal (for example, sodium), an alkaline earth (for example, magnesium), ammonium and NX₄ ⁺ (wherein X is C_1-4 alkyl). Physiologically acceptable salts of a hydrogen atom or an ammo group include salts of organic carboxylic acids such as acetic, lactic, tartaric, malic, isethionic, lactobionic and succinic acids; organic sulfonic acids, such as methanesulphonic, ethanesulphonic, benzenesulphonic and p-toluenesulphonic acids, and inorganic acids, such as hydrochloric, sulphuric, phosphoric and sulphamic acids. Physiologically acceptable salts of a compound of a hydroxy group include the anion of said compound in combination with a suitable cation such as Na⁺, NH₄ ⁺ and NX₄ ⁺ (wherein X is a

C _1-4 alkyl group).

For therapeutic use, salts of compounds of formula (I) will be physiologically acceptable, i.e. they will be salts derived from a physiologically acceptable acid or base. However, salts of acids or bases which are not physiologically acceptable may also find use, for example, in the preparation or purification of a physiologically acceptable compound. All salts, whether or not derived from a physiologically acceptable acid or base are within the scope of the present invention.

The compounds according to the invention may be employed alone or in combination with other therapeutic agents for the treatment of the above infections or conditions. Combination therapies according to the present invention comprise the administration of at least one compound of the formula (I) or a physiologically functional derivative thereof and at least one other therapeutic agent. The compound(s) of formula (I) and therapeutic agent(s) may be administered together in a single formulation or separately and, when administered separately, this may occur sequentially in any order or together. The amounts of the compound(s) of formula(I) and therapeutic agent(s) and the relative timings of administration will be selected in order to achieve the desired combined therapeutic effect. Preferably the combination therapy involves the administration of one compound of formula (I) or a physiologically functional derivative thereof and one of the agents mentioned herein below. Examples of such therapeutic agents include agents that are effective for the treatment of HIV infections or associated conditions such as 3'-azido-3'-deoxythymidine (zidovudine), other 2',3'-dideoxynucleosides such as 2',3'-dideoxycytidine, 2',3'-dideoxyadenosine and 2',3'-dideoxyinosine, carbovir, pentoxifylline, N-acetylcysteine, procysteine, a-trichoxanthin, acyclic nucleosides (for example, acyclovir), 2',3'-didehydrothymidine, protease inhibitors such as N-tert-butyl-dechydro-2-[2(R)-hydroxy-4-phenyl-3-(S)-[[N-(2-quinolycarbonyl)-L-asparginyl]-butyl]-(4aS,78aS)-isoquinoline-3-(S)-carboxamide (RO 31-8959), oxathiolan nucleoside analogues such as cis-1-(2-hydroxymethyl)-1,3-oxathiolan-5-yl)cytosine, 5-chloro-2'3'-dideoxy-3'-fluorouridine, ribavirin, (R)-9-[4-hydroxy-2-(hydroxymethyl)but-1-yl]guanine (H2G), TAT inhibitors such as 7-chloro-5-(2-pyrrolyl)-3H-1,4-benzodiazapin-2(H)-one (RO5-3335) or 7-chloro-1,3-dihydro-5-(1H-pyrrol-2-yl)-3H-1,4-benzodiazapin-2-amine (RO24-7429), interferons such as α-interferon, renal excretion inhibitors such as probenecid, nucleoside transport inhibitors such as dipyridamole, phosphonoformic acid, as well as immunomodulators such as interleukin II, granulocyte macrophage colony stimulating factors, erthyropoetin, soluble CD4 and genetically engineered derivatives thereof. Examples of therapeutic agents which are effective for the treatment of HBV infections include carbovir, oxathiolan nucleoside analogues such as cis-1-(2-hydroxymethyl)-1,3-oxathiolan-5-yl)-cytosine (BCH- 189), 5-chloro-2',3'-dideoxy-3'-fluorouridine, acyclovir and interferons, such as α-interferon. Examples of therapeutic agents which are effective for the treatment of herpes virus infections include acyclovir, (R)-9-[4-hydroxy-2-(hydroxymethyl)butyl]guanine (H2G), 9-[4-hydroxy-3-(hydroxymethyl)-but-1-yl)guanine (penciclovir), the 6-deoxy-diacetate ester of penciclovir (famciclovir), BVaraU, 2-[(2-amino-1,6-dihydro-6-oxo-9H-purin-9-yl)methoxy]ethyl L-valinate, phosponoformic acid and phosphonoacetic acid, ganciclovir, (S)-1-(3-hydroxy-2-phosphonylmethoxypropyl)-cytosine (HPMPC), oxetanocine G, 2'-deoxy-5-iodouridine, and 9-(3-hydroxypropoxy)guanine. Further compounds include those disclosed in EP-A-O 409 575 and EP-A-O 427 777.

Preferably the combination therapy involves the administration of one of the above-mentioned agents and a compound within one of the preferred groups of compounds of formula (I) as described above.

Pharmaceutical formulations containing a compound of the invention may be administered for therapy to a mammal including a human ("the recipient") by any suitable route appropriate to the clinical condition to be treated; suitable routes include oral, rectal, nasal, topical (including buccal, sublingual and transdermal), vaginal and parenteral (including subcutaneous, intramuscular, intravenous and intradermal). Such formulations may be prepared by any method known in the art of pharmacy, for example by bringing into association the active ingredient with the pharmaceutically acceptable carrier(s) or excipient(s).

In general, however, for each of these utilities and indications, a suitable, effective dose will be in the range of 0.5 to 120 mg per kilogram body weight of the recipient per day, preferably in the range of 1 to 90 mg per kilogram body weight per day and most preferably in the range of 2 to 60 mg per kilogram body weight per day. An optimum dose is about 30 mg per kilogram body weight per day. Unless otherwise indicated all weights of active ingredients are calculated as the parent compounds of the compounds according to the invention. In the case of a salt, ester or physiologically functional derivative of a compound according to the invention or a solvate of any thereof the figures would be increased proportionately. The desired dose is preferably presented as two, three, four, five, six, or more sub-doses administered at appropriate intervals throughout the day. These sub-doses may be administered in unit dosage forms, for example, containing from 1 to 1500 mg, preferably from 5 to 1000 mg, most preferably from 10 to 700 mg of active ingredient per unit dosage form. Alternatively, if the condition of the recipient so requires, the dose may be administered as a continuous infusion.

Ideally, the active ingredient should be administered to achieve peak plasma concentrations of the active compound of from about 0.25 to about 100 μM, preferably from about 0.5 to 70 μM, most preferably from about 1 to about 50 μM. This may be achieved, for example, by the intravenous injection of a 0.1 to 5% w/v solution of the active ingredient, optionally in saline, or orally administered, for example, as a tablet, capsule, or syrup containing from about 0.5 to about 100 mg/kg of the active ingredient. Desirable blood levels may be maintained by a continuous infusion to provide from about 0.01 to about 5.0 mg/kg/hour or by intermittent infusions containing from about 0.4 to about 15 mg/kg of the active ingredient.

Formulations of the present invention suitable for oral administration may be presented as discrete units such as capsules, cachets or tablets; as powders or granules; as a solution or suspension in an aqueous or non-aqueous liquid; or as an oil-in-water liquid emulsion or a water-in-oil liquid emulsion.

Compositions suitable for transdermal administration may be presented as discrete patches adapted to remain in intimate contact with the epidermis of the recipient for a prolonged period of time. Such patches suitably contain the active compound 1) in an optionally buffered, aqueous solution or 2) dissolved in an adhesive or 3) dispersed in a polymer. A suitable concentration of the active compound is about 1% to 35%, preferably about 3% to 15%. As one particular possibility, the active compound may be delivered from the patch by ionophoresis as generally described in Pharmaceutical Research, 3(6), 318 (1986).

Pharmaceutical formulations for topical administration according to the present invention may be formulated as an ointment, cream, suspension, lotion, powder, solution, paste, gel, spray, aerosol or oil.

For infections of the eye or other external tissues, for example mouth and skin, the formulations are preferably applied as a topical ointment or cream. When formulated in an ointment, the active ingredients may be employed with either a paraffinic or a water-miscible ointment base. Alternatively, the active ingredients may be formulated in a cream with an oil-in-water cream base or as a water-in-oil base.

Formulations suitable for topical administration to the eye also include eye drops wherein the active ingredient is dissolved or suspended in a suitable carrier, especially an aqueous solvent.

Formulations suitable for topical administration in the mouth include lozenges, pastilles and mouth-washes.

Formulations for rectal administration may be presented as a suppository or as an enema.

Formulations suitable for nasal administration wherein the carrier is a solid include a coarse powder having a particle size for example in the range 20 to 500 microns which is administered in the manner in which snuff is taken, i.e. by rapid inhalation through the nasal passage from a container of the powder held close up to the nose. Suitable formulations wherein the carrier is a liquid, for administration as a nasal spray or as nasal drops, include aqueous or oily solutions and suspensions of the active ingredient.

Suitable formulations for administration by inhalation include fine particle dusts or mists which may be generated by means of various types of metered dose pressurised aerosols, nebulizers or insufflators.

Formulations suitable for vaginal administration may be presented as pessaries, tampons, creams, gels, pastes, foams or spray formulations.

Formulations suitable for parenteral administration include aqueous and non-aqueous sterile injection solutions which may contain anti-oxidants, buffers, bacteriostats and solutes which render the formulation isotonic with the blood of the intended recipient; and aqueous and non-aqueous sterile suspensions which may include suspending agents and thickening agents. The formulations may be presented in unit-dose or multi-dose containers, for example sealed ampoules and vials, and may be stored in a freeze-dried (lyophilized) condition requiring only the addition of the sterile liquid carrier, for example water for injections, immediately prior to use. Extemporaneous injection solutions and suspensions may be prepared from sterile powders, granules and tablets of the kind previously described.

Preferred unit dosage formulations are those containing a daily dose or sub-dose, as herein above recited, or an appropriate fraction thereof, of an active ingredient.

It should be understood that in addition to the ingredients particularly mentioned above, the formulations of this invention may include other agents conventional in the art having regard to the type of formulation in question, for example those suitable for oral administration may include flavouring agents.

A compound of formula (I) or a salt, ester or physiologically functional derivative thereof or a solvate of any thereof may be prepared by the general methods outlined below, these are further features of the invention. In the following description the symbols R¹, R², R³, R⁶, R⁷, R⁸, R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, X and Y have the meanings ascribed to them in formula (I) unless otherwise stated (R^10' is an alternative value of R¹⁰).

The compounds of formula (I) may be prepared by a process which comprises:-

(A) for the preparation of a compound of formula (I) wherein R¹³ and R¹⁴ together form a carbonyl group or R¹³ and R¹⁴ are both hydrogen and R² and R³ are both hydrogen, cyclising a compound of formula (II);

(B) for the preparation of a compound of formula (I) wherein R¹³ and R¹⁴ together form a carbonyl group, cyclising a compound of formula (III)

for example (III) is 3-(3-indolyl)-4-(1H-7-aza-indol-3-yl)maleimide;

(C) for the preparation of a compound of formula (I) wherein R¹³ and R¹⁴ together form a carbonyl group, by reacting a compound of formula (IV)

with an amine of formula R¹ NH₂ or an amine salt of formula R¹ NH₃ X¹ where

X¹ represents an acid anion;

(D) for the preparation of a compound of formula (I) wherein one of X or Y is H and the other is OR¹⁰ or SR¹⁰ by treating a compound of formula (I) wherein one of

X or Y is H and the other one is OR^{1 0'} or SR^10' with an alcohol R^{1 0} OH or a thiol R¹⁰ SH;

(E) for the preparation of a compound of formula (I) wherein X and Y are both H by reacting a compound of formula (I) wherein one of X or Y is H and the other is OR¹⁰ with an appropriate reducing agent, for example zinc-amalgam, in the presence of acid, Raney-nickel, a metal hydride such as lithium aluminium hydride or diisobutylaluminium hydride, or alternatively with an acid, (for example trifluoroacetic acid TFA) and a silane (for example triethylsilane);

(F) for the preparation of a compound of formula (I) wherein X and Y are both H by reacting a compound of formula (I) wherein R¹³ and R¹⁴ together form a carbonyl group with an appropriate reducing agent, for example zinc-amalgam, in the presence of acid; G) for the preparation of a compound of formula (I) wherein one of X or Y is H and the other is OH by reacting a compound of formula (I) wherein R¹³ and R¹⁴ together form a carbonyl group with a reducing agent, for example metal hydrides such as lithium aluminium hydride, sodium cyanoborohydride, or by reaction with zinc-amalgam in the presence of aqueous acid; (H) for the preparation of a compounds of formula (I) wherein one of X or Y is H and the other is OR¹⁰ by reacting a compound of formula (I) wherein R¹³ and R¹⁴ together form a carbonyl group with zinc-amalgam in the presence of acid, for example, hydrochloric acid, and an alcohol R¹⁰ OH, preferably in excess; and thereafter, or simultaneously therewith, effecting one or more of the following optional conversions:-

(i) when the compound of formula (I) is formed, converting it into another compound of formula (I) having different values of R², R³, R⁶ and R⁷ by treatment with an appropriate reagent and/or under suitable conditions;

(ii) removing any remaining protecting groups;

(iii) when the compound of formula (I) is formed, converting it into a pharmaceutically acceptable derivative thereof;

(iv) when the pharmaceutically acceptable derivative of a compound of formula (I) is formed, converting the said derivative into a compound of formula (I), or a different derivative thereof.

For process (A) compounds of formula (I) as defined above may be prepared by reacting compounds of formula (II) with a phosphine, for example triphenylphosphine or a phosphite, for example triethylphosphite, .in a suitable solvent such as collidine, lutidine or t-butylbenzene.

Compounds of formula (II) may be prepared according to the methods described by I.Hughes et al. JCS Perkin 1 (1990), 2475.

For process (B) compounds of formula (I) as defined above may be prepared by reacting a compound of formula (HI) with an oxidising agent such as DDQ (2,3-dichloro-5,6-dicyano-1,4-benzoquinone) in a suitable solvent, such as benzene, toluene, dioxane or xylene, or combinations thereof preferably in the presence of an acid, for example p-toluenesulphonic acid, and at an elevated temperature, preferably in the range of 50-150ºC. Alternatively, cyclisation can be effected using palladium, silver oxide, light optionally with oxygen and preferably with iodine in an inert atmosphere (for example under nitrogen), heat or oxidising agents such as tert-butyl hypochlorite.

Compounds of formula (III) may be prepared by reacting a compound of formula (XV)

with an amine of formula R¹ NH₂ (R¹ as previously defined) or amine salt of formula R¹ NH₃ X¹ (X signifies an acid anion such as halide, carboxylate, carbonate or sulphate), optionally in a suitable solvent for example tetrahydrofuran, dimethylformamide, acetic acid or toluene (or combinations thereof), or with hexamethyldisilazane and methanol in a suitable solvent such as tetrahydrofiiran or dimethylformamide.

Compounds of formula (XV) may be prepared by reacting a compound of formula (XVIII) with a compound of formula (XIX) in the presence of a base, such as triethylamine, ethyl diisopropylamine, or pyridine, and optionally in a suitable solvent, such as dichloromethane.

Compounds of formula (XIX) may be prepared by reacting a compound of formula (XVI) with oxalyl chloride or thionyl chloride, optionally in a suitable solvent, for example dichloromethane or toluene, provided that R³ is a protecting group (for example p-tosyl) when R⁹ represents a heterocyclic ring system.

Compounds of formula (XVIII) may be prepared by hydrolysis of a compound of formula (XX) where R¹⁰ is as hereinbefore defined, using acidic (eg. HCl) or basic (eg. NaOH) conditions.

Compounds of formula (XX) may be prepared by reacting a compound of formula (XXI) with an oxidising agent, such as selenium dioxide or DDQ.

Compounds of formula (XXI) may be obtained by methods known to a skilled person, for example Khim. Geterosikl (1972) (11) 1528-30, J. Amer. Chem. Soc. (1956) 78, 1247.

Compounds of formula (III) may also be prepared by reacting a compound of formula (VIII) where V is a halide, OPO(R¹⁰)₂ or OCOR¹⁰ (where R¹⁰ is as hereinbefore defined), and preferably where R² is a protecting group.

with a compound of formula (IX),

or an acid salt thereof, where Z is OR¹⁰ or SR¹⁰ in a suitable solvent such as dichloromethane in the presence of a base such as triethylamine, ethyldiisopropylamine or pyridine, followed by treatment with an acid, such as p-toluenesulphonic acid or hydrochloric acid. The acid treatment may be optionally replaced by treatment with a mixed anhydride (for example trifluoroacetic anhydride) in the presence of a base (for example pyridine, triethylamine).

Compounds of formula (IX) may be prepared by reacting an alcohol R¹⁰ OH or a thiol of formula R¹⁰SH with a compound of formula (X)

in the presence of an acid, for example hydrochloric acid. Compounds of formula (X) are available commercially or may be prepared by methods known to a skilled person in the art. Compounds of formula (VIII) where V is OCOR¹⁰ or OPO(R¹⁰)₂ may be prepared by reacting a compound of formula (XVIII) with a chloroformate (for example methylchloroformate) or a phosphine chloride (for example diphenylphosphinic chloride) in the presence of a base (for example pyridine, triethylamine).

Compounds of formula (VIII) where V is halide (for example chloride) and R⁸ represents a non-heterocyclic ring system (for example benzene) may conveniently be prepared by reacting a compound of formula (XVII)

with an oxalyl halide (for example oxalyl chloride), optionally in a suitable solvent, for example dichloromethane or tetrahydrofuran.

Compounds of formula (VIII) where V is a halide and R⁸ is a heterocyclic ring system may be prepared by reacting a compound of formula (XVIII) with oxalyl chloride or thionyl chloride optionally in a suitable solvent, for example dichloromethane or toluene, provided that R² is a protecting group (such as p-tosyl).

Compounds of formula (III) may also be prepared by reacting a compound of formula (XI)

with a compound of formula (XII)' wherein L is a leaving group (such as halogen) and M is a metal atom (for example, magnesium), in a suitable solvent for example tetrahydrofuran, 1,4-dioxane, benzene, toluene, diethyl ether, or combinations thereof. Compounds of formula (XI) may be prepared by reacting a compound of formula (XII), wherein L is a leaving group and M is a metal atom, with a compound of formula (XIII) wherein L is a leaving group, in a suitable solvent such as tetrahydrofuran, 1,4- dioxane, diethyl ether, benzene, toluene, or combinations thereof.

Compounds of formula (XIII) may be prepared by reacting an amine of formula R¹NH₂ with a maleic anhydride of formula (XIV)

wherein L is a leaving group. Compounds of formula (XIV) may be obtained commercially or may be prepared by methods known in the art.

Compounds of formula (XII) and (XII)' may be prepared by methods described in Brenner et al, Tetrahedron (1988) 44, 2887-2892.

For process (C) compounds of formula (I) as defined above may be prepared by reacting commercially available amines of formula R¹NH₂ or amine salts of formula R¹ NH₃ X¹ where X represents an acid anion such as halide, acetate, carbonate or sulphate with an anhydride of formula (IV)

Compounds of formula (IV) may be prepared by reacting a compound of formula (XV) with an oxidising agent such as DDQ (2,3-dichloro-5,6-dicyano-1,4-benzoquinone) in a suitable solvent, such as benzene, toluene, dioxane or xylene, or combinations thereol; preferably in the presence of an acid, for example p-toluenesulphonic acid, and at an elevated temperature, preferably in the range of 50-150ºC. Alternatively, cyclisation can be effected using palladium, silver oxide, light (preferably with iodine in an inert atmosphere), heat or oxidising agents such as tert-butyl hypochlorite.

Compounds of formula (XV) can also be prepared by reacting a compound of formula (XVI) with a compound of formula (VIII), where R² is preferably a protecting group when R⁸ is a heterocyclic ring, in the presence of a base, such as triethylamine, ethyl diisopropylamine or pyridine and optionally a suitable solvent, such as dichloromethane.

Compounds of formula (XVI), (VIII) (XVIII) and (XVII) may be obtained commercially or prepared by methods known to a skilled person, for example US patent 3,362,956. It will be appreciated that when R¹, R², R³ are protecting groups, they may be introduced or removed at any stage of the process according to methods known in the art (Theodora W. Greene and Peter G.M. Wuts in Protecting Groups in Organic

Syntheses (2nd Ed), 1991, Wiley and Sons). Preferred protecting groups for the pyrrolo nitrogen in compounds of formula (VIII) are tert-butyloxycarbonyl (BOC), p-toluenesulphonyl (tosyl), benzyl, benxyloxymethyl, methoxy and silyl (eg. tert-butyldimethylsily, triisopropyl).

The introduction of groups R² and R³ where R² and/or R³ are not hydrogen may be performed at any stage of the process. For example the indole nitrogens may be alkylated or acylated with groups R²-L or R³-L where R² and R³ are as previously defined with the exception of hydrogen, and L is a suitable leaving group such as halogen or sulphonate ester (eg. trifluoromethanesulphonate). The reaction preferably taking place in the presence of a base (eg. triethylamine), or a metal hydride (eg. sodium hydride), or an alkyl lithium (eg. n-butyl lithium), and in a suitable solvent (such as dimethylformamide, tetrahydrofiiran, dimethylsulphoxide).

The introduction of groups R⁶ and R⁷ where R⁶ and/or R⁷ are not hydrogen, may be performed at any stage, according to methods known in the art of indole chemistry and aromatic chemistry. For example, a halogen atom may be conveniently introduced using N-halosuccinimides or by the use of a halogen (J.Org.Chem (1951) 16, 1198). A nitro group may for example, be introduced using KNO₃ or HNO₃ in the presence of sulphuric acid or using nitronium tetrafluoroborate. Acyl (eg. formyl) or sulphonyl groups may, for example, be introduced by methods described in Chem. Ind. (1981),

338 and J.Amer.Chem.Soc. (1946) 68, 1272 respectively.

Compounds of formula (I) may be converted into an ester by reaction with an appropriate esterifying agent, for example, an acid halide or anhydride. Where it is desired to isolate a compound of formula (I) as an acid addition salt, for example a physiologically acceptable acid addition salt, the salt may be formed by reacting the compound of formula (I) in the form of the free base with the appropriate acid. The two reactants are preferably used in equivalent amounts and the reaction may be carried out in a suitable solvent such as an alcohol, for example ethanol, an ester, for example ethyl acetate, or an ether, for example tetrahydrofuran. One salt of a compound of formula (I) may be converted into another salt using standard methods, for example where it is desired to convert a salt of a compound of formula (I) with an acid which is not physiologically acceptable into a salt with a physiologically acceptable acid. An ester or salt may be converted into the parent compound, for example, by hydrolysis.

The invention will now be illustrated by reference to the following examples:

A. Preparation of methyl 7-aza-3-indolyl-acetate

A solution of 7-azaindole-3-acetonitrile (J. Amer. Chem. Soc. (1956) 78, 1247) (50.5g, 0.32mol) in cone. HCL (600ml) was heated under reflux for 20 hours. After cooling and evaporation in vacuo to a small volume, methanol (700ml) was added, and the mixture heated under reflux until esterification was complete (approximately 3 hours). The solvent was evaporated in vacuo. the residue partitioned between EtOAc and sodium carbonate solution, the organic layer separated, dried (Na₂SO₄) and evaporated to a small volume, whereupon the product crystallised.

M.p. 83-84ºC. B. Preparation of methyl 7-aza-1-p-tosyl-3-indolyl-acetate

To a solution of A (1.56g, 8.2mmol) in CH₂Cl₂ (16.4ml) at 0°C was added sodium hydroxide solution (2M, 16.4ml) with rapid stirring, followed by tetra n- butyl ammonium hydrogen sulphate (40mg). After 10 minutes, p-tosyl chloride (1.72g) was added in portions over 5 minutes. The mixture was then stirred at room temperature for 5 hours. The layers were separated, the organic layer washed with 10% sodium bicarbonate solution, dried (Na₂SO₄), evaporated, and purified by flash column chromatography over silica. Elution with hexane/EtOAc (4:1), then (2:1), and finally (1:1) gave the product B as a white solid.

M.p. 112°C.

C. Preparation of methyl 7-aza-1-allyl-3-indolyl-acetate

To a solution of A (8.0g, 42mmol) in DMF (100ml) at 0°C was added sodium hydride (80%, 1.39g, 1.1 eq) with stirring. After 15 minutes at 0°C, and room temperature for 1 hour, allyl bromide (4.33ml, 1.2eq) in DMF (50ml) was added dropwise. After 2 days at room temperature the solvent was evaporated in vacuo. the residue partitioned between EtOAc and saturated sodium bicarbonate solution, the organic phase separated, dried (Na₂SO₄) and evaporated. Purification by flash chromatography over silica, eluting with hexane/EtOAc (4:1), (2:1), and then (1:1) gave the title compound C as an oil.

By a similar method, and replacing allyl bromide with ethyl iodide, the following intermediate was prepared.

C2. Methyl 7-aza-1-ethyl-3-indolyl acetate.

D. Preparation of methyl 7-aza-1-(3-cyanopropyl)-3-indolyl-acetate

To a solution of A (190mg, 1mmol) in dry acetonitrile (50ml) at room temperature under nitrogen was added 1,8-diazabicyclo[5,4,0]undec-7-ene (69mg, 0.46mmol), followed by acrylonitrile (530mg, 10mmol), and the mixture heated to 80°C for 2 hours. The solvent was removed in vacuo. and the residue purified by flash chromatography over silica, eluting with hexane, then hexane/EtOAc (3:2). Evaporation of the appropriate fractions afforded the title compound D as a colourless oil.

E. Preparation of 7-aza-1-p-tosyl-3-indolyl-acetic acid

To a suspension of B (3.44g, 10mmol) in methanol (80ml) at room temperature was added sodium hydroxide solution (1M, 40ml) and the mixture stirred for 30 minutes. The mixture was acidified to pH3, concentrated to a small volume and partitioned between water and ethyl acetate. The organic layer was dried (MgSO₄), evaporated and triturated with ethyl acetate to afford the product E as a white solid.

M.p. 198-201°C.

By a similar method, the following intermediates were prepared:

E2. 7-aza-1-allyl-3-indolyl-acetic acid (from C)

M.p. 154-1-55°C

E3. 7-aza-1-(3-cyanopropyl)-3-indolyl acetic acid (from D)

M.p. 183°C.

F. Preparation of 7-aza-1-ethyl-3-indolyl-acetic acid

To a solution of 7-aza-3-acetonitrile (1.7g, 10.8mmol) in dry DMF (15ml) at room temperature under nitrogen was added sodium hydride (80%, 260mg) and the mixture stirred for 1 hour. Ethyliodide (1.69g, 10.8mmol) in dry DMF (5ml) was added and the mixture stirred overnight at room temperature. EtOAc was added, the mixture washed with water, then brine, the organic layer separated, dried (MgSO₄), evaporated and purified by flash chromatography over silica. Elution with hexane then hexane/EtOAc (4:1) gave 7-aza-1-ethyl-indole-3- acetonitrile. A solution of this compound (1.5g, 8.1mmol) in concentration HCl (15.6ml) was heated under reflux for 20 hours. The mixture was concentrated to a small volume, and adjusted to pH6, whereupon the title compound F precipitated as a white solid, which was filtered off.

M.p. 164-167°C.

G. Preparation of 3-(1H-7-aza-1-(3-cyanopropyl)-indol-3-yl)-4-(1H-indol-3-yl) maleic anhydride

To a solution of 1-triisopropylsilyl indole (3.72g, 13.6mmol) in dry CH₂Cl₂ (100ml) at 0°C under nitrogen was added oxalyl chloride (1.81g, 14.3mmol) with stirring. After 30 minutes the solvent was evaporated in vacuo. the residue dissolved in dry CH₂Cl₂ (100ml), and added dropwise to a solution of E3 (3.11g, 13.6mmol) and ethyl diisopropylamine (3.51g, 27mmol) in CH₂Cl₂ (100ml) at room temperature. After stirring overnight, the mixture was washed with sodium biocarbonate solution, dried (MgSO₄), evaporated, and purified by flash chromatography over silica. Elution with hexane, then hexane/EtOAc (3 :2), then (1:1), (2:3) and finally (3 :7) gave the title compound G as a red solid.

M.p. 105°C.

By a similar method, the following intermediates were prepared.

G2. 3-(1H-7-aza-1-ethyl-indol-3-yl)-4-(1H-indol-3-yl) maleic anhydride (from F).

G3. 3-(1H-7-aza-1-allyl-indol-3-yl)-4-(1H-indol-3-yl) maleic anhydride (from E2).

G4. 3-(1H-7-aza-1-p-tosyl-indol-3-yl)-4-(1H-5-chloroindol-3-yl) maleic anhydride (from E).

H. Preparation of 3-(1H-7-aza-1-ethyl-indol-3-yl)-4-(1H-7-aza-1-p-tosyl- indol-3-yl)maleic anhydride

To a suspension of E (2.21g, 6.69mmol) in dry dichloromethane (100ml) under nitrogen at 10°C was added oxalyl chloride (850mg, 6.69mmol) followed by dry DMF (50μl). The mixture was stirred at room temperature for 30 minutes, then evaporated in vacuo. The residue was re-dissolved in dry dichloromethane (50ml) and added to a solution of S (1.46g, 6.69mmol) and ethyl diisopropylamine (3.45g, 26.8mmol) in dry dichloromethane (50ml). The mixture was stirred at room temperature overnight, washed with sodium bicarbonate solution, separated, dried (MgSO₄) and concentrated to a small volume. This was placed on a flash silica column and eluted with EtOAc, then EtOAc/CH₂Cl₂ (4:1). Fractions containing the product were pooled and evaporated to afford the title compound H as a yellow solid.

M.p. 125°C

I. Preparation of 3-(1H-7-aza-indol-3-yl)-4-(1H-5-chloroindol-3-yl)

maleic anhydride

A solution of G4 (1.43g, 2.76mmol) in methanolic KOH solution (0.1M, 180ml) was heated under reflux for 3 hours. The mixture was cooled, neutralised with 0.1M HCl, and extracted with EtOAc. The organic layer was washed with 10% sodium bicarbonate solution, dried (Na₂SO₄), evaporated and purified by flash column chromatography over silica. Elution with hexane/EtOAc (1:1), then EtOAc, gave the title compound I.

By a similar method the following intermediate was obtained:

12. 3-(1H-7-aza-1-ethyl-indol-3-yl)-4-(1H-7-aza-1-indol-3-yl)maleic anhydride

(from H)

M.p. 225°C

J. Preparation of 3-(1H-7-aza-1-ethyl-indol-3-yl)-4-(1H-indol-3-yl)

maleimide

A mixture of G2 (900mg) and ammonium acetate (2.7g) was heated at 140°C for one hour. The mixture was cooled, neutralised with sodium hydroxide solution (2N) and extracted with EtOAc. The organic layer was separated, washed with brine, separated, dried (MgSO₄), evaporated, and purified by flash column chromatography over silica. Elution with hexane, then hexane/EtOAc (3:2) gave the title compound J as a red solid.

M.p. 242°C.

K. Preparation of 3-(1H-7-azaindol-3-yl)-4-( 1H-5-chloroindol-3-yl) maleimide

A solution of I (60mg, 0.16mmol), methanol (33 μl, 0.82mmol), 1,1,1,3,3,3- hexamethyldisilazane (0.35ml, 1.65mmol) and dry DMF (5ml) were stirred at room temperature overnight. The reaction mixture was quenched by the addition of EtOH, evaporated in vacuo. and triturated with a mixture of hexane/EtOAc (1 : 1) to give the title compound K as a red solid.

M.p. >300°C.

By a similar method the following intermediates were prepared:

K2. 3-(1H-7-aza-1-allyl-indol-3-yl)-4-(1H-indol-3-yl) maleimide (from G3)

M.p. 210-211ºC

K3. 3-(1H-7-aza-1-(3-cyanopropyl)-indol-3-yl)-4-(1H-indol-3-yl) maleimide (from G )

M.p. 168-170ºC.

K4. 3-(1H-7-aza-1-ethyl-indol-3-yl)-4-(1H-7-aza-indol-3-yl) maleimide (from 12)

M.p. 293°C

L. Preparation of 12H,13H-(3-cyanopropyl)pyrido[3',2':4.5]pyrrolo[2,3-a]

pyrrolo[3,4-c]carbazole -5,7-dione

To a solution of K3 (100mg, 0.26mmol) in isopropanol (100ml) was added iodine (67mg) and the solution degassed on an ultrasonic bath. The solution was then irradiated, at room temperature under nitrogen, using a Hanovia photochemical reactor for 36 hours. The mixture was treated with saturated sodium thiosulphate solution and evaporated to a small volume. Water (5ml) and EtOAc (2ml) were added, and the mixture filtered under suction to afford the product L as a yellow solid.

M.p. >330°C.

By a similar method, the following final products were prepared:

L2. 12H,13-Ethylpyrido[3',2':4,5]pyrrolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7-dione (from J).

M.p. >300°C.

L3. 12H,13-Allylpyrido[3',2':4,5]pyrrolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7-dione (from K2).

M.p. >300°C

L4. 12H,13H-9-Chloropyrido[3',2':4,5]pyrrolo[2,3 a]pyrrolo[3,4-c]carbazole-5,7- dione (from K).

M.p. >300°C.

L5. 12H,13-Ethylpyrido[2,3-b]pyrrolo[3,4-c]pyrido[3^,,2^,:4,5]pyrrolo[3,2-g]indole- 5,7-dione (from K4)

M.p. >300°C

M. Preparation of 12H-13-(2,4-Dihydroxypropyl)pyrido[3',2':4,5]pyrrolo[2,3-a] pyrrolo[3,4-c]carbazole-5,7-dione

A mixture of L3 (33mg), osmium tetroxide (one crystal), N-methylmorpholine- N-oxide (16mg), acetone (50ml) and water (5 drops) was stirred at room temperature overnight. A further 8mg of N-methylmorpholine-N-oxide was added and stirring continued for a further day. The solvent was then removed, the residue dissolved in the minimum volume of DMF, and the product purified by reverse-phase HPLC with water/acetonitrile (1 : 1) as eluant. Fractions containing pure product were pooled and evaporated to give the title compound M as a yellow solid.

M.p. Decomposes above 200°C

N. Preparation of 3-Chloro-4-(1H-7-aza-indol-3-yl)-1-methylmaleimide

To a solution of ethyl magnesium bromide (63 mmol) in THF (15 ml) at room temperature under nitrogen was added a solution of 7-azaindole (7.44g, 63 mmol) in a mixture of THF (15ml) and benzene (20ml) over 30 minutes with stirring. The mixture was heated at 50°C for 80 minutes and cooled. 2,3- Dichloromaleimide (2.52g, 14 mmol) in THF (45ml) was added over 40 minutes at room temperature. The mixture was then heated at 80°C for 2 hours, cooled and quenched by the addition of aqueous ammonium chloride solution (80ml) and EtOAc (200ml). Insoluble material was removed by filtration, the layers separated, and the aqueous layer washed with EtOAc (70ml). The organic fractions were combined, dried (Na₂ SO₄), and evaporated. The red residue was chromtographed over flash SiO₂, eluting with hexane/EtOAc (3:1), (2:1), (1:1), (1:2) and EtOAc.

Fractions containing the product were pooled and evaporated to afford the title compound as yellow crystals.

M.p. 257-258°C O. Preparation of 3-(1H-indol-3-yl)-4-(1H-7-aza-indol-3-yl)maleimide

To a solution of indole magnesium bromide (16.1 mmol) in THF (17ml) at room temperature under nitrogen was added a solution of the product of N in THF (20ml) over 15 minutes. The solution was then heated under reflux for 2½ hours, and cooled. Brine (50ml) and EtOAc (70ml) was added, the organic layer separated, dried (Na₂ SO₄) and evaporated. The residue was chromatographed over flash SiO₂, eluting with hexane/EtOAc (3:1), (2:1), (1:1) and (1:2), to give 3-(3-indolyl)-4-(1H-7-aza-indol-3-yl)-1-methyl maleimide as a red solid. A solution of the latter component (215mg) in dioxane (10ml) and potassium hydroxide solution (10%, 10ml) was heated under reflux for 6 hours. Acetic acid (3ml) was added and all of the solvents evaporated off under reduced pressure. The resulting orange solid was triturated with acetone (20ml) and THF (20ml), the white insoluble material filtered off, and the filtrate evaporated in vacuo. The resulting red/orange solid was heated at 140°C with ammonium acetate (4g) for 60 minutes and the solvents removed in vacuo. The red oil was chromatographed over flash SiO₂, eluting with hexane/EtOAc (3:1), (2:1), (1:1) and (1:2) to give the compound O as an orange solid.

M.p. 314-315°C

P. Preparation of 12H, 13H - Pyrido [3',2':4,5] pyrrolo [2,3-a]

pyrrolo [3,4-c] carbazole -5,7-dione

A solution of O (40mg) and iodine (~10mg) in isopropanol (75ml) was irradiated for 21 hours using a medium pressure Hanovia lamp whilst a slow stream of air was passed through the solution. The mixture was evaporated to a small volume (~3ml) and chromatographed over flash SiO₂, eluting with successive mixture of acetone/toluene (1:1), (2:1) and (3:1). This afforded the title compound as a yellow solid after trituration with CHCl₃/MeOH (4: 1).

M.p. > 320ºC

Q. Preparation of 12H, 13H-Pyrido [3',2':4.5] pyrrolo [2,3-a]

pyrrolo [3,4-c] carbazole-5,7-dione hydrochloride

A solution of P above (60mg) in THF (30ml) was treated with a solution of ethyl acetate (2ml) which had previously been saturated with hydrogen chloride gas. An orange precipitate formed instantly. After one hour at room temperature the mixture was centrifuged (3000 rpm for 10 minutes), the liquid decanted off, and the resulting solid suspended in acetone. The mixture was centrifuged as before, and the acetone/centrifugation procedure repeated on a further two occasions. The resulting orange solid was dried in vacuo to give the title hydrochloride salt as a green-yellow solid.

M.p. >330^OC.

R. Preparation of 12H, 13H-Pyrido [2',3':4,5] pyrrolo [2,3-a] pyrrolo [3,4-c]

carbazole-5,7-dione-1-oxide

A solution of P above (60mg) and purified m-chloroperoxy benzoic acid (32mg) in THF (500ml) was heated at 60°C for 7 days. The mixture was concentrated to ~100ml and washed with sodium bicarbonate solution. The product resided in the organic phase as a fine suspension and was isolated by centrifugation, washed with water and acetone, to afford the product as a yellow solid.

M.p. >300ºC

S. Preparation of methyl 7-aza-1-ethyl-3-glyoxalate

To a suspension of selenium dioxide (250mg, 2.29mmol) in dioxane (2ml) was added water (41mg, 2.29mmol) and the mixture placed at 50°C for 30 minutes. The solution was cooled to room temperature, a solution of C2 (500mg, 2.29mmol) in dioxane added, and the mixture heated under reflux for 2 hours. The mixture was then cooled, washed three times with ethyl acetate, the organic fractions combined, washed with sodium bicarbonate solution, dried (MgSO4), evaporated and purified by flash chromatography over silica. Elution with hexane, then hexane/EtOAc (4:1), then (1:1) gave the compound S as a yellow solid.

Examples

The following examples illustrate pharmaceutical formulations according to the invention containing at least one active ingredient (compound of formula (I)) such examples are not intended to limit the scope of the invention. Tablet Formulations

The following formulations A, B and C are prepared by wet granulation of the ingredients with a solution of povidone, followed by addition of the magnesium stearate and compression.

Formulation A

mg/tablet mg/tablet

(a) Active ingredient 250 250

(b) Lactose B.P. 210 26

(c) Povidone B.P. 15 9

(d) Sodium Starch Glycollate 20 12

(e) Magnesium Stearate 5 3

500 300

Formulation B

mg/tablet mg/tablet

(a) Active ingredient 250 250

(b) Lactose 150 -

(c) Avicel PH-101 60 26

(d) Povidone B.P. 15 9

(e) Sodium Starch Glycollate 20 12

(f) Magnesium Stearate 5 3

500 300

Formulation C

mg/tablet

Active ingredient 100

Lactose 200

Starch 50

Povidone 5

Magnesium stearate 4

359 The following formulations, D and E, are prepared by direct compression of the admixed ingredients.

Formulation D

mg/capsule

Active Ingredient 250

Pregelatinised Starch NF 15 150

400

Formulation E

mg/capsule

Active Ingredient 250

Lactose 150

Avicel 100

500

Formulation F (Controlled Release Formulation)

The formulation is prepared by wet granulation of the following ingredients with a solution of povidone followed by addition of the magnesium stearate and compression. mg/tablet

(a) Active Ingredient 500

(b) Hydroxypropylmethylcellulose 112

(Methocel K4M Premium)

(c) Lactose B.P. 53

(d) Povidone B.P.C. 28

(e) Magnesium Stearate 7

700

Drug release takes place over a period of about 6-8 hours and is complete after 12 hours. Capsule Formulations

Formulation A

A capsule formulation is prepared by admixing the ingredients of Formulation D in Example 3 above and filling into two-part hard gelatin capsule.

Formulation B mg/capsule

(a) Active ingredient 250

(b) Lactose B.P. 143

(c) Sodium Starch Glycollate 25

(d) Magnesium Stearate 2

420

Capsules are prepared by admixing the above ingredients and filling into two-part hard gelatin capsules.

Formulation C mg/capsule

(a) Active ingredient 250

(b) Macrogol 4000 BP 350

600

Capsules are prepared by melting the Macrogol 4000 BP, dispersing the active ingredient in the melt and filling the melt into two-part hard gelatin capsules.

Formulation D mg/capsule

Active ingredient 250

Lecithin 100

Arachis Oil 100

450 Capsules are prepared by dispersing the active ingredient in the lecithin and arachis oil and filling the dispersion into soft, elastic gelatin capsules.

Formulation E (Controlled Release Capsule)

The following controlled release capsule formulation is prepared by extruding ingredients (a), (b) and (c) using an extruder, followed by spheronisation of the extrudate and drying. The dried pellets are then coated with the release-controlling membrane (d) and filled into two-piece, hard gelatin capsules. mg/capsule

(a) Active Ingredient 250

(b) Microcrystalline Cellulose 125

(c) Lactose BP 125

(d) Ethyl Cellulose 13

513

Injectable Formulation

Formulation A

Active ingredient 0.200g

Hydrochloric acid solution, 0.1M q.s. to pH 4.0 to 7.0

Sodium hydroxide solution, 0.1M q.s. to pH 4.0 to 7.0

Sterile water q.s. to 10ml The active ingredient is dissolved in most of the water (35º -40ºC) and the pH adjusted to between 4.0 and 7.0 using the hydrochloric acid or the sodium hydroxide as appropriate. The batch is then made up to volume with the water and filtered through a sterile micropore filter into a sterile amber glass vial 10ml and sealed with sterile closures and overseals. Formulation B

Active ingredient 0.125 g

Sterile, pyrogen-free, pH 7 phosphate buffer, q.s. to 25 ml

Intramuscular injection

Active Ingredient 0.20 g

Benzyl Alcohol 0.10 g

Glycofurol 75 1.45 g

Water for Injection q.s. to 3.00 ml

The active ingredient is dissolved in the glycofurol. The benzyl alcohol is then added and dissolved, and water added to 3 ml. The mixture is then filtered through a sterile micropore filter and sealed in sterile amber glass vials 3 ml.

Syrup

Active ingredient 0.25 g

Sorbitol Solution 0.10 g

Glycerol 2.00 g

Sodium Benzoate 0.005 g

Flavour, Peach 17.42.3169 0.0125 ml

Purified Water q.s. to 5.00 ml

The active ingredient is dissolved in a mixture of the glycerol and most of the purified water. An aqueous solution of the sodium benzoate is then added to the solution, followed by addition of the sorbitol solution and finally the flavour. The volume is made up with purified water and mixed well.

Suppository mg/suppository

Active Ingredient 250

Hard Fat, BP (Witepsol H15 - Dynamit Nobel) 1770

2020 One-fifth of the Witepsol H15 is melted in a steam-jacketed pan, at 45ºC maximum.

The active ingredient is sifted through a 200 lm sieve and added to the molten base with mixing, using a Silverson fitted with a cutting head, until a smooth dispersion is achieved. Maintaining the mixture at 45ºC, the remaining Witepsol H15 is added to the suspension and stirred to ensure a homogenous mix. The entire suspension is passed through a 250 lm stainless steel screen and, with continuous stirring, is allowed to cool to 40ºC. At a temperature of 38ºC to 40ºC, 2.0g of the mixture is filled into suitable, 2 ml plastic moulds. The suppositories are allowed to cool to room temperature.

Pessaries mg/pessary

Active ingredient 250

Anhydrate Dextrose 380

Potato Starch 363

Magnesium Stearate 7

1000

The above ingredients are mixed directly and pessaries prepared by direct compression of the resulting mixture.

Antiviral Testing (a) HeLa-CD4⁺ cell assay for evaluating susceptibility of HIV to

antiviral compounds

Susceptibility of HIV to inhibitors was determined by infection of HT4-6C cell monolayers as described by Larder, B.A., Chesebro, B. & Richman, D.D.

Antimicrob. Agents Chemother. 1990 34, 436-441. Briefly cells were seeded in

24-well multiwells at 5×10⁴ cells per well and incubated overnight at 37ºC in growth medium (DMEM10). Monolayers were infected with 100-200pfu of cell-free virus in 0.2ml of DMEM containing 5% fetal bovine serum plus antibiotics (DMEM5) and incubated for 1 hour at 37ºC to allow virus adsorption. Following this time, 0.8ml of DMEM5 (with or without inhibitor) was added to each well and cultures were incubated at 37ºC for 2-3 days. Monolayers were fixed with 10% formaldehyde solution in PBS and stained with 0.25% crystal violet in order to visualize virus plaques. Individual foci of multinucleated gian cells (plaques) were apparent using this staining procedure. ID₅₀ values were derived from plots of percent plaque reduction versus inhibitor concentration.

(b) HSV Assay

Herpes Simplex Virus types 1 (HSV 1) and 2 (HSV 2) were assayed in monolayers of Vero cells in multiwell trays. The virus strains used were SC16 and 186 for HSV-1 and HSV-2 respectively. Activity of compounds was determined in the plaque reduction assay, in which a cell monolayer was infected with a suspension of the appropriate HSV, and then overlaid with nutrient carboxymethyl cellulose in the form of a gel to ensure that there was no spread of virus throughout the culture. A range of concentrations of compound of known molarity was incorporated in the nutrient carboxymethyl cellulose overlay. Plaque numbers at each concentration is expressed as percentages of the control and a dose-response curve was drawn.

(c) CMV Assay

Human cytomegalovirus (HCMV) was assayed in monolayers of either MRC5 cells (human embryonic lung) in multiwell trays. The standard CMV strain AD 169 was used. Activity of compounds is determined in the plaque reduction assay, in which a cell monolayer is infected with a suspension of HCMV, and then overlaid with nutrient carboxymethyl cellulose in the form of a gel to ensure that there is no spread of virus throughout the culture. A range of concentrations of compound of known molarity was incorporated in the nutrient agarose overlay. Plaque numbers at each concentration of drug are expressed as percentage of the control and a dose-response curve is drawn.

EXAMPLE IC₅₀uM

L 0.1

L3 0.39 (d) VZV Assay

Clinical isolates of varicella zoster virus (VZV) were assayed in monolayers of MRC-5 cells. MRC-5 cells are derived from human embryonic lung tissue. A plaque reduction assay was used in which a suspension of the virus stock was used to infect monolayers of the cells in multiwell trays. A range of concentrations of the compound under test of known molarity was added to the wells. Plaque numbers at each concentration were expressed as percentages of the control and a dose response curve was contructed. From these curves the 50% inhibitory concentration of each drug was determined.

(e) Cell Toxicity

Cell toxicity is assessed in cell growth inhibition assay. Subconfluent cultures of

Vero cells grown on 96-well microtiter dishes are exposed to different dilutions of drug, and cell viability determined daily on replicate cultures using uptake of a tetrazolium dye (MTT). The concentration required for 50% inhibition of cell viability at 96 hours is termed CCID₅₀.

EXAMPLE CCIC₅₀uM

P >500

L2 >500

Claims

1. A compound of formula (I) :

wherein R¹ represents

-H.

-COR¹⁰; CH₂OR¹⁰; CO₂R¹⁰; OR¹⁰ [where R¹⁰ is C_1-6 alkyl, C_3-7 cycloalkyl, aryl (for example phenyl), arylalkyl (for example benzyl), C_1-6 alkenyl, or H];

-NR¹¹R¹²; CH₂NR¹¹R¹² [where R¹¹ and R¹², which may be the same or different each represent H, COR¹⁰ (where R¹⁰ is hereinbefore defined), C_1-6 alkyl, C_3-7 cycloalkyl, aryl, arylalkyl, or R¹¹ and R¹² together with the N atom to which they are attached form a 3-,4-,5- or 6- membered heterocyclic ring (for example piperidine, pyrrolidine) in which from 1 to 3 carbon atom(s) may be replaced by hereroatom(s) independently selected from O, N and S (for example morpholino, piperazine) which ring may, where possible, be partially or completely unsaturated];

R² and R³, which may be the same or different, are each independently selected from:-

-H; -OR¹⁰; COR¹⁰; CO₂R¹⁰ (where R¹⁰ is hereinbefore defined);

-C_1-4alkyl, C_2-4alkenyl or C_{3- 8} cycloalkyl where the alkyl, alkenyl or cycloalkyl moiety may be optionally substituted by one or more substituents selected from halogen, cyano, nitro, azido, COR¹⁰, CO₂R¹⁰, OCOR¹⁰, SOR¹⁰, CO₂NR¹¹R¹², C_3-8cycloalkyl, OR¹⁰, SR¹⁰, SO₂R¹⁰, NR¹¹R¹² (where R¹⁰, R¹¹ and R¹² are each as defined above); [(where T is NR¹⁰, S or O, Z is NH, S or O and W is NR¹ -R¹² (where

R¹¹ and R¹² are each as defined above)]; heterocycle; -N-heterocycle; heteroaryl or aryl optionally substituted by one or more substituents selected from OR¹⁰, NR¹¹R¹² SR¹⁰, SO₂R¹⁰, CO₂R¹⁰ nitro, cyano, SCN, C_1-6alky!, C_3-6cycloalkyl, haloalkyl (for example trifluoromethyl), hydroxylalkyl, OCOR¹⁰, SOR¹⁰, CONR¹¹R¹², SO₂NR¹¹R¹², halogen and methylene dioxy (where R¹⁰, R¹¹ and R¹² are each as defined above);

-NR¹¹R¹² (where R¹¹ and R¹² are each as defined above);

R⁶ and R⁷, which may be the same or different, each represent one or more ring substituent(s) selected from:

-H;

-C_1-6alkyl optionally substituted by OR¹⁰ (where R¹⁰ is hereinbefore defined), halogen, haloalkyl (for example trifluoromethyl), or NR¹¹R¹² (where R¹¹ and R¹² are as hereinbefore defined);

-cyano; nitro; halogen; methylene dioxy; OR¹⁰; SR¹⁰; SOR¹⁰; SO₂R¹⁰; CO₂R¹⁰; OCOR¹⁰, SO₂NR¹¹R¹²; NHSO₂R¹⁰; CONR¹¹R¹²; NHCOR¹⁰ and NR^{1 1}R¹² (where R¹⁰, R¹¹ and R¹² are as defined above);

R⁸ and R⁹, which may be the same or different, each together with the carbon atoms to which they are attached form an unsaturated 6-membered carbocyclic ring in which from 1 to 3 carbon atom(s) may be replaced by nitrogen atom(s), providing that at least one ring structure contains at least one nitrogen atom, which may optionally be substituted with an oxide group.

R¹³ and R¹⁴ may together form a carbonyl group (>=O) or R¹³ is X and R¹⁴ is Y and both represent H, or X and Y are different and one of X or Y represents H and the other represents OR¹⁰ or SR¹⁰, (where R¹⁰ is as defined above); or a salt, ester or physiologically functional derivative thereof or a solvate of any thereof.

2. A compound of formula (I) as claimed in Claim 1 wherein both R⁸ and R⁹ form a 6-membered aromatic ring each in which one carbon atom is replaced by a nitrogen in each ring system in the 1 and 11 positions respectively.

3. A compound of formula (I) as claimed in Claim 1 wherein both R⁸ and R⁹ form a 6-membered aromatic ring in which only one ring system has one carbon atom replaced by a nitrogen atom and is in the 1 or 11 position respectively.

4. A compound of formula (I) as claimed in any of Claims 1 to 3 wherein R¹³ and R¹⁴ together form a carbonyl group.

5. A compound of formula (I) as claimed in Claims 1 to 4 where either R⁸ or R⁹ are substituted by one substituent other than hydrogen.

6. Use of a compound of formula (I) as defined in any of Claims 1 to 5 in medical therapy particularly in the treatment or prophylaxis of a viral infection.

7. Use of a compound as defined in Claim 6 where the viral infection is caused by a herpes virus.

8. Use of a compound as defined in any of Claims 1 to 5 in the manufacture of a medicament for use in the treatment or prophylaxis of a viral infection.

9. Use as claimed in Claim 8 wherein the viral infection is caused by CMV.

10. A method for the treatment of a viral infection such as CMV comprising administering to the subject an antivirally therapeutic amount of a compound of formula (I) as defined in Claim 1.

11. A pharmaceutical formulation comprising a compound of formula (I) as defined in any of Claims 1 to 5 and at least one pharmaceutically acceptable carrier or excipient.

12. A pharmaceutical formulation as claimed in Claim 11 adapted for parenteral administration.

13. A pharmaceutical formulation as claimed in Claim 11 adapted for oral administration and formed into a tablet or capsule.

14. A process for the preparation of a compound of formula (I) which comprises:-

(A) for the preparation of a compound of formula (I) wherein R¹³ and R¹⁴ together form a carbonyl group or R¹³ and R¹⁴ are both hydrogen and R² and R³ are both hydrogen, cyclising a compound of formula (II);

(B) for the preparation of a compound of formula (I) wherein R¹³ and R¹⁴ together form a carbonyl group, cyclising a compound of formula (El);

(C) for the preparation of a compound of formula (I) wherein R¹³ and R¹⁴ together form a carbonyl group, by reacting a compound of formula (IV)

with an amine of formula R¹ NH₂ or R¹ NH₃ X¹ where X¹ represents an acid anion;

(D) for the preparation of a compound of formula (I) wherein X is H and Y is

OR^{1 0} or SR¹⁰, by treating a compound of formula (I) wherein X is H and

Y is OH, OR^10' or SR^{10 '} with a compound R¹⁰ OH or R¹⁰ SH;

(E) for the preparation of a compound of formula (I) wherein X and Y are both H by reacting a compound of formula (I) wherein X or Y is H and the other is OR ¹⁰ with an appropriate reducing agent;

(F) for the preparation of a compound of formula (I) wherein X and Y are both H by reacting a compound of formula (I) wherein R¹³ and R¹⁴ together form a carbonyl group with an appropriate reducing agent; (G) for the preparation of a compound of formula (I) wherein X or Y is H and the other is OH by reacting compounds of formula (I) wherein R¹³ and R¹⁴ together form a carbonyl group with a reducing agent;

(H) for the preparation of compounds of formula (I) wherein X or Y is H and the other is OR¹⁰ by reacting compounds of formula (I) wherein R¹³ and R¹⁴ together form a carbonyl group with zinc-amalgam in the presence of acid and an alcohol R¹⁰OH; and thereafter, or simultaneously therewith, effecting one or more of the following optional conversions:-

(i) when the compound of formula (I) is formed, converting it into another compound of formula (I) having different values of R², R³, R⁶ and R⁷ by treatment with an appropriate reagent and/or under suitable conditions;

(ii) removing any remaining protecting groups;

(iii) when the compound of formula (I) is formed, converting it into a pharmaceutically acceptable derivative thereof;

(iv) when the pharmaceutically acceptable derivative of a compound of formula (I) is formed, converting the said derivative into a compound of formula (I), or a different derivative thereof.

15. A process for the preparation of a compound of formula (III) comprising

(A) reacting a compound of formula (XV)

with an amine of formula R²NH₂ or an amine salt of formula R¹NH₃X¹ (where X¹ is an acid anion);

(B) by reacting a compound of formula (VIII) with a compound of (IX), or an acid salt thereof where V is halide, OCOR¹⁰ or OPO(R¹⁰)₂;

where Z is OR¹⁰ or SR¹⁰ in a suitable solvent;

(C) by reacting a compound of formula (XI) wherein L is a leaving group and M is a metal atom, with a compound of formula (XII)

in a suitable solvent;

16. A process for the preparation of a compound of formula (XV).

(A) by reacting a compound of formula (XVIII) with a compound of formula

(XIX);

(B) by reacting a compound of formula (XVI) with a compound of formula

(VIII)