BENZODIAZEPINE DERIVATIVES, COMPOSITIONS CONTAINING THEM AND THEIR USE IN THERAPY

Abstract: Compounds of formula (I), and salts and prodrugs thereof, wherein one of W, X, Y or Z is N, another of W, X, Y or Z is N, O or S atom or NR<8>, and the other two of W, X, Y and Z are N or CR<8>, and the dotted circle represents two double bonds; R<1> represents optionally substituted C1-6 alkyl, or C3-7 cycloalkyl; R<2> represents optionally substituted C1-6 alkyl, halo, CONR<6>R<7>, SO(C1-6alkyl), SO2(C1-4alkyl), CONHSO2R<9>, SO2NHCOR<9>, SONHR<10>, cyano, or B(OH)2; R<3> represents H, C1-6 alkyl or halo; m is 0, 1 or 2; n is 0, 1, 2 or 3; are CCK and/or gastrin antagonists. They and compositions thereof are therefore useful in therapy.

Description: BENZODIΆZEPINE DERIVATIVES, COMPOSITIONS CONTAINING THEM AND THEIR USE IN THERAPY This invention relates to benzodiazepine compounds which are useful as antagonists of cholecysto inin and gastrin receptors. Cholecysto inins (CCK) and gastrin are structurally related neuropeptides which exist in gastrointestinal tissue and in the central nervous system (see, V. Mutt, Gastrointestinal Hormones. G.B.J. Green, Ed., Raven Press, N.Y., p.169 and G. Nission, ibid, p.127). Cholecystokinins include CCK-33, a neuropeptide of thirty-three amino acids in its originally isolated form (see, Mutt and Jorpes, Biochem. J. 125, 678 (1971)), its carboxylterminal octapeptide, CCK-8 (also a naturally- occurring neuropeptide and the minimum fully active sequence) , and 39- and 12-amino acid forms. Gastrin occurs in 34-, 17- and 14-amino acid forms, with the minimum active sequence being the C-terminal tetrapeptide, Trp-Met-Asp-Phe-NH , which is the common structural element shared by both CCK and gastrin. CCKs are believed to be physiological satiety hormones, thereby possibly playing an important role in appetite regulation (G. P. Smith, Eatinσ and Its Disorders, A. J. Stunkard and E. Stellar, Eds, Raven Press, New York, 1984, p. 67), as well as stimulating colonic motility, gall bladder contraction, pancreatic enzyme secretion and inhibiting gastric emptying. They reportedly co-exist with dopamine in certain mid-brain neurons and thus may also play a role in the functioning of dopaminergic systems in the brain, in addition to serving as neurotransmitters in their own right (see A. J. Prange et al. , "Peptides in the Central Nervous System", Ann. Repts. Med. Che 17. 31, 33 [1982] and references cited therein; J. A. Williams, Biomed Res. 3 107 [1982]; and J.E. Morley, Life Sci. 30. 479 [1982]). The primary role of gastrin, on the other hand, appears to be stimulation of the secretion of water and electrolytes from the stomach and, as such, is involved in control of gastric acid and pepsin secretion. Other physiological effects of gastrin then include increased mucosal blood flow and increased antral motility. Rat studies have shown that gastrin has a positive trophic effect on the gastric mucosa, as evidenced by increased DNA, RNA and protein synthesis. There are at least two subtypes of cholecystokinin receptors termed CCK-A and CCK-B (T.H. Moran et al. , "Two brain cholecystokinin receptors: implications for behavioural actions", Brain Res. , 362. 175-79 [1986]). Both subtypes are found both in the periphery and in the central nervous system. CCK and gastrin receptor antagonists have been disclosed for preventing and treating CCK-related and/or gastrin related disorders of the gastrointestinal (GI) and central nervous (CNS) systems of animals, especially mammals, and more especially those of humans. Just as there is some overlap in the biological activities of CCK and gastrin, antagonists also tend to have affinity for both CCK-B receptors and gastrin receptors. Other antagonists have activity at the CCK-A subtype. Selective CCK antagonists are themselves useful in treating CCK-related disorders of appetite regulatory systems of animals as well as in potentiating and prolonging opiate-mediated analgesia [see P. L. Faris et al. , Science 226. 1215 (1984)], thus having utility in the treatment of pain. CCK-B and CCK-A antagonists have also been shown to have a direct analgesic effect [M.F. O'Neill et al. , Brain Research. 534 287 (1990)]. Selective CCK and gastrin antagonists are useful in the modulation of behaviour mediated by dopaminergic and serotonergic neuronal systems and thus have utility in the treatment of schizophrenia and depression (Rasmussen et. al. , 1991, Eur. J. Pharmacol.. 209, 135-138; Woodruff et. al. , 1991, Neuropeptides. 19, 45-46; Cervo et. al. , 1988, Eur. J. Pharmacol.. 158, 53-59), as a palliative for gastrointestinal neoplasms, and in the treatment and prevention of gastrin-related disorders of the gastrointestinal system in humans and animals, such as peptic ulcers, Zollinger-Ellison syndrome, antral G cell hyperplasia and other conditions in which reduced gastrin activity is of therapeutic value, see e.g. U.S. Patent 4,820,834. Certain CCK antagonists are useful anxiolytic agents and can be used in the treatment of panic and anxiety disorders. CCK has been reported to evoke the release of stress hormones such as adrenocorticotrophic hormone, β- endorphin, vasopressin and oxytocin, CCK may function as a mediator of responses to stress and as part of the arousal system. CCK-A receptors are now known to be present in a number of areas of the CNS and may be involved in modulating all of the above. CCK may be involved in the regulation of stress and its relationship with drug abuse e.g. alleviation of the benzodiazepine withdrawal syndrome (Singh et. al. , 1992, Br. J. Pharmacol.. 105. 8-10) and neuroadaptive processes. Since CCK and gastrin also have trophic effects on certain tumours [K. Okyama, Hokkaido J. Med. Sci.. 206- 216 (1985)], antagonists of CCK and gastrin are useful in treating these tumours [see, R.D. Beauchamp et al.. Ann. Surσ.. 202, 203 (1985)]. In the light of discussion in C. Xu et al. , Peptides. 8, 1987, 769-772, CCK antagonists may also be effective in neuroprotection. CCK receptor antagonists have been found to inhibit the contractile effects of CCK on iris sphincter and ciliary muscles of monkey and human eyes (Eur. J. Pharmacol., 211(2), 183-187; A. Bill et al.. Acta Physiol. Scand. , 138. 479-485 [1990]), thus having utility in inducing miosis for therapeutic purposes. A class of benzodiazepine antagonist compounds has been reported which binds selectively to brain CCK (CCK-B and CCK-A) and gastrin receptors [see M. Bock et al..J. Med Chem.. 32. 13-16 (1989)]. European patent application no. 0 167 919 discloses benzodiazepine CCK and gastrin antagonists substituted in the 3-position by, inter alia, a phenyl urea and at the 5-position by an optionally substituted phenyl or pyridyl group. British patent application no. 1,034,872 discloses benzodiazepines substituted at the 3-position by an unsubstituted amino group or a substituted amino group containing up to eight carbon atoms, and at the 5- position by a monocyclic aryl moiety. The only 5- substituents specifically disclosed are phenyl (substituted or unsubstituted) and thienyl. There is no disclosure of a phenyl urea substituent at C-3. British patent no. 1,309,947 discloses benzodiazepines substituted at the 5-position by, inter alia, a heterocyclic group, and at the 3-position by H, alkyl, alkoxy, alkylthioalkyl, phenyl, benzyl or hydroxybenzyl. The compounds are said to have tranquilizer, muscle relaxant, antispasmodic, anticonvulsant and hypnotic effects. There is no suggestion of the phenyl urea substituent of the compounds of the present invention. Nor is there any suggestion that the compounds are CCK or gastrin antagonists. The present invention provides benzodiazepine compounds of formula (I) : (I) wherein: one of W, X, Y or Z represents a nitrogen atom, another of W, X, Y or Z is a nitrogen, oxygen or sulphur atom or a group NR 8 where R 8 is H or Cι_.galkyl, and the other two of W, X, Y and Z each independently represent nitrogen atoms or groups CR 8 , and the dotted circle represents two double bonds; R 1 represents Cι__ alkyl, C 3 -.7 cycloalkyl, cyclopropylmethyl, (CH2)qimidazolyl, (CH2)qtetrazolyl, (CH2)qtriazolyl, (where q is 1, 2 or 3), CH2CO2R 5 (where R 5 is C 1 _4 alkyl) or a group CH 2 C0NR 6 R 7 (where R 6 and R 7 each independently represents H or Cι_4alkyl, or R 6 and R 7 together form a chain (CH2)p where p is 4 or 5) ; R 2 represents C^-g alkyl, halo, (CH2) r tetrazol Yl/ optionally substituted in the tetrazole ring by C 1 _ 4 alkyl, (CH 2 ) r imidazolyl, CONR 6 R 7 , SO(C 1 _. 6 alkyl) , S0 2 (C 1 _. 6 alkyl) , CONHS0 2 R 9 , S0 2 NHCOR 9 , SONHR 10 , cyano, B(OH)2 or (CH 2 ) r C0 H, where r is zero, 1 or 2, R 9 is Cι_ 6 alk l, optionally substituted aryl, 2,2- difluorocyclopropane or trifluoromethyl, and R 10 is a nitrogen containing heterocycle; R 3 represents H, C±-β alkyl or halo; is 0, 1 or 2; n is 0, 1, 2 or 3; and salts or prodrugs thereof. It will be appreciated that formula (I) is intended to embrace all possible isomers, including optical isomers, and mixtures thereof, including racemates. The present invention includes within its scope prodrugs of the compounds of formula I above. In general, such prodrugs will be functional derivatives of the compounds of formula I which are readily convertible in vivo into the required compound of formula I. Conventional procedures for the selection and preparation of suitable prodrug derivatives are described, for example, in "Design of Prodrugs", ed. H. Bungaard, Elsevier, 1985. When R 1 represents Ci-galkyl, alkyl means linear or branched chain alkyl. Examples of suitable alkyl groups include methyl, ethyl, isopropyl and isobutyl groups. When R 1 represents cycloalkyl, examples of suitable cycloalkyl groups include cyclopropyl, cyclopentyl and cyclohexyl groups, preferably cyclopropyl. Halo includes fluoro, chloro and bromo. Preferably halo will be fluoro or chloro. Suitable examples of the substituent include imidazolyl, N-methylimidazolyl and thiazolyl, preferably thiazolyl. In one subgroup of compounds of formula (I) R 1 represents C-±-β alkyl, C 3 _7 cycloalkyl, cyclopropylmethyl, (CH2)qimidazolyl (where q is 1, 2 or 3) , CH 2 CO2R 5 (where R 5 is C - 4 alkyl) or a group CH2CONR°R 7 (where R 6 and R 7 each independently represents a hydrogen atom or a 1-4 alkyl group, or R 6 and R 7 together form a chain (CH2) where p is 4 or 5) ; R 2 represents Cι_g alkyl, halo, (CH2)s tetraz °l_.l (CH2)si m i dazo lylf cyclopropyl or a group (CH2) s Cθ2H, where s is zero, 1 or 2; and m and n each represent 1. Preferably R 1 is Ci-galkyl, more preferably methyl or iso-butyl. When one substituent R 2 is present, it will preferably be located at the 3- or 4-position of the phenyl ring, more preferably the 3-position. When two substituents R 2 are present, they will preferably be located at the 3- and 4-positions. Suitable values for R 9 include methyl, ethyl, i- propyl, t-butyl, phenyl and trifluoromethyl. When R 9 is optionally substituted aryl, this will preferably be optionally substituted phenyl. Suitable substituents include Cι_ 4 alkyl, Cι_4alkoxy, halo and trifluoromethyl. Preferred are compounds wherein R 9 is unsubstituted aryl or aryl substituted by C^-galkyl, for example phenyl substituted by Ci-gal yl in the ortho position. When R 9 is Ci-galkyl, it will preferably represent Cι_ 4 alkyl. Particularly preferred are methyl and iso- propyl. When R 2 is SO2NHR 10 . suitable values of R 10 include, for example, thiazole, thiadiazole and pyrazine. Preferably R 2 is tetrazolyl, methyl or COOH, more preferably 5-tetrazolyl. Preferably a is 1. Preferably n is zero. Preferably q is 1. Preferably r is zero. One subgroup of compounds according to the invention is represented by formula (II) : (ID wherein Z is a sulphur atom or a group NR 1 A R, where R1-"- 0 _ i•s H or methyl; R 20 is Ci-ealkyl; and R 21 is Ci-galkyl, tetrazolyl or CO2H, preferably tetrazolyl. Preferably the salts of the compounds of formula (I) are pharmaceutically acceptable, but non-pharmaceutically acceptable salts may be used for the preparation of pharmaceutically acceptable salts. The pharmaceutically acceptable salts of the compounds of formula (I) include the conventional non-toxic salts or the quaternary ammonium salts of the compounds from formula (I) formed, e.g., from inorganic or organic acids or bases. For example, such conventional non-toxic salts include those derived from inorganic acids such as hydrochloric, hydrobromic, sulphuric, sulphamic, phosphoric, nitric and the like; and the salts prepared from organic acids such as acetic, propionic, succinic, glycolic, steric, lactic, malic, tartaric, citric, ascorbic, palmoic, maleic, hydroxymaleic, phenylacetic, glutamic, benzoic, salicylic, sulphanilic, 2-acetoxy benzoic, fumaric, toluenesulphonic, methanesulphonic, ethane disulphonic, oxalic and isothionic. The pharmaceutically acceptable salts of the present invention can be synthesized from the compound of formula (I) which contain a basic or acidic moiety by conventional chemical methods. Generally, the salts are prepared by reacting the free base or acid with stoichiometric amounts or with an excess of the desired salt-forming inorganic or organic acid or base in a suitable solvent or various combinations of solvents. For example, an acid of formula (I) may be reacted with an appropriate amount of a base, such as an alkali or alkaline earth metal hydroxide e.g. sodium, potassium, lithium, calcium, or magnesium, or an organic base such as an amine, e.g. dibenzylethylenediamine, trimethylamine, piperidine, pyrrolidine, benzyla ine, and the like, or a quaternary ammonium hydroxide such as tetramethylammonium hydroxide. The present invention also encompasses a pharmaceutical composition comprising a compound of formula (I) , or a salt or prodrug thereof and a pharmaceutically acceptable carrier or diluent. The compounds of formula (I) and their salts and prodrugs, may be administered to animals, preferably to mammals, and most especially to a human subject either alone or, preferably, in combination with pharmaceutically acceptable carriers or diluents, optionally with known adjuvants, such as alum, in a pharmaceutical compostion, according to standard pharmaceutical practice. The compounds can be administered orally, parenterally, including by intravenous, intramuscular, intraperitoneal or subcutaneous administration, or topically. For oral use of an antagonist of CCK, according to this invention, the selected compounds may be administered, for example, in the form of tablets or capsules, or as an aqueous solution or suspension. In the case of tablets for oral use, carriers which are commonly used include lactose and corn starch, and lubricating agents, such as magnesium stearate, are commonly added. For oral administration in capsule form, useful diluents include lactose and dried corn starch. When aqueous suspensions are required for oral use, the active ingredient is combined with emulsifying and suspending agents. If desired, certain sweetening and/or flavouring agents may be added. For intramuscular, intraperitoneal, subcutaneous and intravenous use, sterile solutions of the active ingredient are usually prepared, and the pH of the solutions should be suitably adjusted and buffered. For intravenous use, the total concentration of solutes should be controlled in order to render the preparation isotonic. For topical administration, a compound of formula (I) may be formulated as, for example, a suspension, lotion, cream or ointment. For topical administration, pharmaceutically acceptable carriers are, for example, water, mixtures of water and water-miscible solvents such as lower alkanols or arylalkanols, vegetable oils, polyalkylene glycols, petroleum based jelly, ethyl cellulose, ethyl oleate, carboxymethylcellulose, polyvinylpyrrolidone, isopropyl myristate and other conventionally-employed non-toxic, pharmaceutically acceptable organic and inorganic carriers. The pharmaceutical preparation may also contain non-toxic auxiliary substances such as emulsifying, preserving, wetting agents, bodying agents and the like, as for example, polyethylene glycols 200, 300, 400 and 600, carbowaxes 1,000, 1,500, 4,000, 6,000 and 10,000, antibacterial components such as quaternary ammonium compounds, phenylmercuric salts known to have cold sterilizing properties and which are non-injurious in use, thimerosal, methyl and propyl paraben, benzyl alcohol, phenyl ethanol, buffering ingredients such as sodium chloride, sodium borate, sodium acetates, gluconate buffers, and other conventional ingredients such as sorbitan monolaurate, triethanolamine, oleate, polyoxyethylene sorbitan monopalmitylate, dioctyl sodium sulfosuccinate, monothioglycerol, thiosorbitol, ethylenediamine tetraacetic acid, and the like. The compounds of formula (I) antagonise CCK and/or gastrin and are useful for the treatment and prevention of disorders including central nervous system disorders wherein CCK and/or gastrin may be involved. Examples of such disease states include gastrointestinal diseases, including gastrointestinal ulcers, such as peptic and duodenal ulcers, irritable bowel syndrome, gastroesophagenal reflux disease or excess pancreatic or gastrin secretion, acute pancreatitis, or motility disorders; central nervous system disorders, including central nervous system disorders caused by CCK interaction with dopamine, serotonin and other monoamine neurotransmitters, such as neuroleptic disorders, tardive dyskinesia, Parkinson's disease, psychosis or Gilles de la Tourette syndrome; depression; schizophrenia; disorders of appetite regulatory systems; Zollinger- Ellison syndrome, antral and cell hyperplasia, or pain. The compounds of formula (I) are particularly useful in the treatment or prevention of neurological disorders involving anxiety disorders and panic disorders, wherein CCK and/or gastrin is involved. Examples of such disorders include panic disorders, anxiety disorders, panic syndrome, anticipatory anxiety, phobic anxiety, panic anxiety, chronic anxiety and endogenous anxiety. The compounds of formula (I) are also useful for directly inducing analgesia, opiate or non-opiate mediated, as well as anesthesia or loss of the sensation of pain. The compounds of formula (I) may further be useful for preventing or treating the withdrawal response produced by chronic treatment or abuse of drugs or alcohol. Such drugs include, but are not limited to benzodiazepines, cocaine, alcohol and nicotine. The compounds of formula (I) may further by useful in the treatment of stress and its relationship with drug abuse. The compounds of formula (I) may further be useful in the treatment of oncologic disorders wherein CCK may be involved. Examples of such oncologic disorders include small cell adenocarcinomas and primary tumours of the central nervous system glial and neuronal cells. Examples of such adenocarcinomas and tumours include, but are not limited to, tumours of the lower oesophagus, stomach, intestine, colon and lung, including small cell lung carcinoma. The compounds of formula (I) may also be useful as neuroprotective agents, for example, in the treatment and/or prevention of neurodegenerative disorders arising as a consequence of such pathological conditions as stroke, hypoglycaemia, cerebral palsy, transient cerebral ischaemic attack, cerebral ischaemia during cardiac pulmonary surgery or cardiac arrest, perinatal asphyxia, epilepsy, Huntington's chorea, Alzheimer's disease, Amyotrophic Lateral Sclerosis, Parkinson's disease, Olivo-ponto-cerebellar atrophy, anoxia such as from drowning, spinal cord and head injury, and poisoning by neurotoxins, including environmental neurotoxins. The compounds of formula (I) may further be used to induce miosis for therapeutic purposes after certain types of examination and intraocular surgery. An example of intraocular surgery would include cateract surgery with implantation of an artificial lens. The CCK antagonist compounds of this invention can be used to prevent miosis occuring in association with iritis, ureitis and trauma. The present invention therefore provides a compound of formula (I) or a salt or prodrug thereof for use in the preparation of a medicament. The present invention also provides a compound of formula (I) for use in therapy. In a further or alternative embodiment the present invention provides a method for the treatment or prevention of a physiological disorder involving CCK and/or gastrin which method comprises administration to a patient in need thereof of a CCK and/or gastrin antagonising amount of a compound of formula (I) . When a compound according to formula (I) is used as an antagonist of CCK or gastrin in a human subject, the daily dosage will normally be determined by the prescibing physician with the dosage generally varying according to the age, weight, and response of the individual patient, as well as the severity of the patient's symptoms. However, in most instances, an effective daily dosage wll be in the range from about 0.005mg/kg to about lOOmg/kg of body weight, and preferably, of from 0.05mg/kg to about 50mg/kg, such as from about 0.5mg/kg to about 20mg/kg of body weight, administered in single or divided doses. In some cases, however, it may be necessary to use dosages outside these limits. For example, animal experiments have indicated that doses as low as lng may be effective. In effective treatment of panic syndrome, panic disorder, anxiety disorder and the like, preferably about 0.05 mg/kg to about 0.5 mg/kg of CCK antagonist may be administered orally (p.o.), administered in single or divided doses per day (b.i.d.). Other routes of administration are also suitable. For directly inducing analgesia, anaesthesia or loss of pain sensation, the effective dosage preferably ranges from about 100 ng/kg to about lmg/kg by intravenous administration. Oral administration is an alternative route, as well as others. In the treatment or irritable bowel syndrome, preferably about 0.1 to 10 mg/kg of CCK antagonist is administered orally (p.o.), administered in single or divided doses per day (b.i.d.). Other routes of administration are also suitable. The use of a gastrin antagonist as a tumour palliative for gastrointestinal neoplasma with gastrin receptors, as a modulator of central nervous activity, treatment of Zollinger-Ellison syndrome, or in the treatment of peptic ulcer disease, an effective dosage of preferably about 0.1 to about 10 mg/kg administered one- to-four times daily is indicated. For use as neuroprotective agents the effective dosage preferably ranges from about 0.5mg/kg to about 20mg/kg. Because these compounds antagonise the function of CCK in animals, they may also be used as feed additives to increase the food intake of animals in daily dosage of preferably about 0.05mg/kg to about 50mg/kg of body weight. The compounds of formula (I) may be prepared by processes analogous to those described in European Patent Specification No. 0167919. For example, a compound of formula (I) may be prepared from an intermediate of formula (III) (III) wherein W, X, Y, Z, R , and n are as defined for formula (I) ; by reaction with an isocyanate of formula (IV) (iv) wherein R 2 and m are as defined for formula (I) . The reaction is preferably conducted in a suitable organic solvent, such as an ether, for example, tetrahydrofuran, at room temperature. The isocyanate of formula (IV) may be generated in situ from the corresponding amine by treatment with triphosgene. Intermediates of formula (III) may be prepared from compounds of formula (V) (V) wherein W, X, Y, Z, R 3 and n are as defined for formula (I) and G is a protecting group; by reaction with a reagent suitable to introduce the group R , for example a halide of formula R-^Hal where Hal represents halo such as bro o or iodo, followed by deprotection. The reaction is carried out in the presence of a base, such as an alkali metal hydride or an alkaline earth metal carbonate, for example sodium hydride or caesium carbonate. Compounds of formula (V) may be prepared from compounds of formula (VI) (VI) wherein W, X, Y, Z, R 3 and n are as defined for formula (I) , by a reaction sequence comprising: (i) reaction with a compound of formula (VII) Ύ COOH NHG (VII) wherein G is as defined above, in the presence of a base, such as a tertiary amine, for example triethylamine or N- methyl morpholine, and a coupling reagent. Any of the coupling reagents commonly used in peptide synthesis are suitable, for example, 1,3-dicyclohexylcarbodiimide (DCC) or isobutyl chloroformate. (ii) Treatment with gaseous ammonia, preferably in the presence of a mercury containing catalyst, such as mercury(II) chloride. The reaction is conveniently effected in a suitable organic solvent, such as an ether, for example, tetrahydrofuran. (iii) Treatment with an organic acid, for example acetic or propionic acid, optionally in the presence of an ammonium salt, for example ammonium acetate. Compounds of formula (VI) may be prepared according to the procedures described in Journal of Heterocyclic Chemistry. 1975, 12., 49-57 and Journal of the Chemistry Society, Perkin Transactions I, 1989, 1139-1145. Where the above-described process for the preparation of the compounds according to the invention gives rise to mixtures of stereoisomers these isomers may, if desired, be separated, suitably by conventional techniques such as preparative chromatography. The novel compounds may be prepared in racemic form, or individual enantiomers may be prepared either by enantiospecific synthesis or by resolution. The novel compounds may, for example, be resolved into their component enantiomers by standard techniques, such as the formation of diastereomeric pairs by salt formation with an optically active acid, such as (-)-di-p-toluoyl-L- tartaric acid and/or (+)-di-p-toluoyl-D-tartaric acid followed by fractional crystallization and regeneration of the free base. The novel compounds may also be resolved by formation of diastereomeric esters or amides, followed by chromatographic separation and removal of the chiral auxiliary. Alternatively, enantiomers of the novel compounds may be separated by HPLC using a chiral column. During any of the above synthetic sequences it may be necessary and/or desirable to protect sensitive or reactive groups on any of the molecules concerned. This may be achieved by means of conventional protecting groups, such as those described in Protective Groups in Organic Chemistry, ed. J.F.W. McO ie, Plenum Press, 1973; and T.W. Greene and P.G.M. Wutts, Protective Groups in Orσanic Synthesis. John Wiley & Sons, 1991. The protecting groups may be removed at a convenient subsequent stage using methods known from the art. The following examples are provided to assist in a further understanding of the invention. Particular materials employed, species and conditions are intended to be further illustrative of the invention and not limitative of the scope thereof. EXAMPLE 1: N-r3(R.S)-2,3-Dihydro- l-methyl-5-( l- methylimidazol-2-yl)-2-oxo-lH-l,4-benzodiazepin-3-yl]-N / -C3- methylphenyllurea Step 1: l,3-Dihydro-3CR.S)-(benzyloxycarbonylamino)-5-(l- _aethyIi_Qida_.ol-2-yl)-2H-l,-r-ber_zodiazepin-2-one To a stirred, cooled (< 10°C) solution of α-(isopropylthio)- N α -(benzyloxycarbonyl)glycine (1.4g) in anhydrous dichloromethane (40ml), under a nitrogen atmosphere, was added dropwise N-methylmorpholine (0.5g) followed by isobutylchloroformate (0.68g). The solution was stirred at 5°C for 10 minutes then heated to reflux. 2-Aminophenyl-(l- methylimidazol-2-yl)methanone (l.Og, J. Het. Chem. 1975, 12, 49-57) in anhydrous dichloromethane (10ml) was added dropwise and the resulting yellow solution heated at reflux for 1 hour then stirred at ambient temperature for 16 hours. The reaction mixture was washed with IN citric acid, brine then dried (sodium sulphate) and evaporated to afford a yellow oil (2.1g). Rf = 0.1 in ethyl acetate/n-hexane (1:3) on silica (trace of amine, 0.2). The crude (isopropylthio)glycinamide was dissolved in anhydrous tetrahydrofuran (100ml) and the ice cooled solution was saturated with ammonia gas. Mercuric chloride (1.35g) was added and the passage of ammonia continued for 3 hours. The mixture was filtered and the filtrate concentrated. The residue was dissolved in glacial acetic acid (30ml), treated with ammonium acetate (1.4g) and the resulting mixture stirred at ambient temperature for 18 hours. The solvent was evaporated and the residue partitioned between ethyl acetate (20ml) and IN sodium hydroxide solution (25ml). The organic layer was separated, dried (magnesium sulphate) then evaporated to give a gummy solid ( lg) which was purified by column chromatography on silica using ethyl acetate/petroleum ether (60-80) (1:1) to ethyl acetate/methanol (9:1) as eluant. The title compound was obtained as a colourless solid (0.38g). .E NMR (250MHz, CDClg) δ 3.95 (3H, s); 5.12 (2H, m); 5.18 (IH, d, J = 8Hz); 6.65 (IH, d, J = 8Hz); 6.9 (IH, d, J = 8Hz); 7.0 (IH, s); 7.1- 7.5 (8H, m); 7.55 (IH, d, J = 8Hz). Step 2: l t 3-Dihydro-3(R,S)-(benzyloxycarbonylamino)-l- niethyl-5-(l-methylimidazol-2-yl)-2H-l,4-benzodiazepin-2-one T o a s tirre d s olu ti o n o f l , 3 - dihydro - 3 (R , S )- (benzyloxycarbonylamino)-5-( l-methylimidazol-2-yl)-2H-l,4- benzodiazepin- 2-one (348mg) in anhydrous dimethylformamide (5ml), at ambient temperature, was added sodium hydride (40mg of a 55% oil dispersion). After 30 minutes iodomethane (142mg) was added and the mixture was stirred for 18 hours. The solvent was evaporated then the residue was partitioned between ethyl acetate and water. The organic layer was separated and evaporated to give a gummy residue which was purified by column chromatography on silica using ethyl acetate/petroleum ether (60-80) (2:1) to ethyl acetate/methanol (95:5) to afford the title compound as a yellow powder (140mg). R f = 0.2 in ethyl acetate on silica plates. X H NMR (250MHz, CDClg) 6 3.43 (3H, s); 3.94 (3H, s); 5.05-5.20 (2H, m); 5.29 (IH, d, J = 8Hz); 6.71 (IH, d, J = 8Hz); 7.01 (IH, s); 7.12 (IH, s); 7.25- 7.70 (9H, m). Step 3 : N- r3 (R,S )-2.3 -Dihydro- l-methyl- 5-( l- methylimidazol-Σ-yD-Σ-oxo-lH-l^-benzodiazepin-S-yll-N^rS- methylphenyl]urea To a solution of l, 3-dihydro- l-methyl-3(R,S)- (ben__yloxycarbonylamino)-5-(l-πιethyliι__idazol-2-yl)-2H-l,4- benzodiazepin-2-one (O.llg) in methanol (30ml) was added 90% formic acid (2ml) and this mixture was added to a stirred suspension of 10% palladium on carbon (0.2g) in methanol (lOml). The reaction mixture was stirred at ambient temperature for 30 minutes then filtered and the solvent evaporated. The residue was partitioned between ethyl acetate (20ml) and 10% sodium carbonate solution (20ml). The organic phase was separated, dried (magnesium sulphate) then evaporated to give l,3-dihydro-3(R,S)-amino-l-methyl-5-(l- methyliι__dazol-2-yl)-2H-l,4-benzodiazepin-2-one (50mg) which was used without further purification. A solution of this crude amine (50mg) in anhydrous tetrahydrofαran (3ml) was treated with m-tolylisocyanate (30mg). After 1 hour the resulting colourless precipitate was collected by filtration and washed with diethyl ether to afford the title compound (40mg) as a colourless solid of mp 222-223°C. Η NMR (360MHz, CDClg) δ 2.30 (3H, s); 3.44 (3H, s); 3.98 (3H, s); 5.52 (IH, d, J = 8Hz); 6.85-7.70 (11H, m). (Found: C, 63.96; H, 5.54; N, 20.41. C22H 2 2 N 6 O 2- 0 - 5H 2 O requires C, 64.22; H, 5.63; N, 20.43%). EXAMPLE 2: N-_ 3(R.S)-2.3-Dihv_ ro-l-(2-methylpropyl)-2-oxo-5- ( thiazol- 2-yl )- lH- 1.4-b enzodiaz epin-3 - yn -N - . 3- methylphenyl_urea Step 1: l,3-Dihydro-3(R.S)-(benzyloxycarbonylamino)-5- (thiazol-2-yl)-2H-l,4-benzodiazepin-2-one The title compound (2.03g, 46%) was obtained from α- (isopropylthio)-N α -(benzyloxycarbonyl)glycine and 2- aminophenyl-(thiazol-2-yl)methanone (J. Het. Chem. 1975, 12, 49-57 ) as described in Example 1. mp 205°C (dec.) ( dichloromethane/n-hexane ) . Rf = 0.25 in ethyl acetate/petroleum ether (60-80) (1:1) on silica plates; H NMR (360MHz, d 6 -DMSO) δ 5.07 (2H, s); 5.17 (IH, d, J = 9Hz); 7.26- 7.39 (7H, m); 7.64 (IH, dd, J χ = 7Hz, J 2 = 8Hz); 7.88 (IH, d, J = 7Hz); 7.95-8.00 (2H, m); 8.50 (IH, d, J = 7Hz); 10.92 (IH, broad s); MS, FAB+ m/z 393 for (M+H) + . (Found: C, 60.61; H, 4.15; N, 14.20. C 2 oH 16 N4θ 3 S. 0.2H 2 O requires C, 60.66; H, 4.17; N, 14.15%). Step 2: l,3-Dihydro-3(R,S)-(benzyloxycarbonylamino)-l-(2- methylpropyl)-5-(thiazol-2-yl)-2H-l,4-benzodiazepin-2-one The title compound (500mg) was obtained from 1,3-dihydro- 3(R,S)-(benzyloxycarbonylamino)-5-(thiazol-2-yl)-2H-l,4- benzodiazepin-2-one and l-iodo-2-methylpropane using a procedure similar to that described in Example 1. mp 115- 117°C. R f = 0.45 in ethyl acetate/petroleum ether (60-80) (1:1) on silica plates; Η NMR (360MHz, CDClg) δ 0.58 (3H, d, J = 7Hz); 0.71 (3H, d, J = 7Hz); 1.66-1.77 (IH, ); 3.43 (IH, dd, J χ = 6Hz, J 2 = 14Hz); 4.29 (IH, dd, J 1 = 9Hz, J 2 = 14Hz); 5.09-5.18 (2H, m); 5.41 (IH, d, J = 8Hz); 6.67 (IH, d, J = 8Hz); 7.30-7.93 (11H, m). Step 3: N-.3(R,S)-2,3-Dihvdro-l- (2-methylpropyl)-2-oxo-5- (thiazol- 2-yl)- lH- l ,4-b enzodiazepin-3- yn -N - . 3- methylphenyl]urea Crude l,3-dihydro-3(R,S)-amino-5-(thiazol-2-yl)-2H-l,4- benzodiazepin-2-one (220mg) was obtained from 1,3-dihydro- 3(R,S)-(benzyloxycarbonylamino)-5-thiazol-2-yl)-2H-l,4- benzodiazepin-2-one as described in Example 1, except that the reaction time was 36 hours. A solution of this crude amine (127mg) in anhydrous tetrahydrofuran (2ml) was treated with m-tolyl isocyanate (45.5mg). After 2 hours the solvent was evaporated and the product purified by column chromatography (HPLC) on silica using ethyl acetate/petroleum ether (60-80) (1:1) as eluant to afford the title product (8mg). mp 222°C (dec). R f = 0.35 in ethyl acetate/petroleum ether (60-80) (1:1) on silica plates; X H NMR (360MHz, CDClg) δ 0.59 (3H, d, J = 6Hz); 0.71 (3H, d, J = 6Hz); 1.69-1.78 (IH, m); 3.45 (IH, dd, J χ = 6Hz, J 2 = 14Hz); 4.30 (IH, dd, J χ = 9Hz, J 2 = 14Hz); 5.63 (lh, broad s); 6.74-7.92 (11H, m); MS, FAB + m/z 448 for (M+H) + . EXAMPLE 3: N-.3(R.S)-2,3-Dihydro-l-(2-methylpropyl)-2-oxo-5- (thiazol-2-yl)-lH-l,4-benzodiazepin-3-yn-N -r3-(tetrazol-5- yDphenyllurea Step 1: 5-(3-Nitrophenyl)tetrazole To a solution of 3-cyanonitrobenzene (20g) in l-methyl-2- pyrrolidinone (200ml) was added triethylamine hydrochloride (27.9g) followed by sodium azide (26.4g). The mixture was heated at 160°C for 1.5 hours, then cooled to ambient temperature, poured into ice water (1000ml) and acidified using 5M HCl. The solid which precipitated from the mixture was filtered, washed with water and dried under vacuum at 50°C to afford the title tetrazole (22. lg, 86%) as a beige powder, mp 154-156°C. Η NMR (360MHz, CDC1 3 ) δ 7.59 (IH, dd, J = 8Hz); 8.19 (IH, d, J = 8Hz), 8.36 (IH, d, J = 8Hz); 8.86 (IH, s). Step 2: 5-(3-Aminophenyl)tetrazole hydrochloride To a solution of 5-(3-nitrophenyl)tetrazole (22g) in ethanol (500ml) was added 10% palladium on carbon (1.5g, 7% ( / w )) in hydrochloric acid (23ml of a 5M solution). The mixture was hydrogenated at 40 psi for 10 minutes then the catalyst filtered off and washed with water. The solvents were evaporated in υacuo and the brown solid azeotroped with toluene (4 x 100ml). The resulting solid was triturated with hot ethanol to give 5-(3- aminophenyDtetrazole hydrochloride (16.3g) as a beige powder, mp 203-205°C. Η NMR (360MHz, D 2 0) δ 7.63 (IH, d, J = 8Hz), 7.75 (IH, dd, J = 8Hz), 8.00 (2H, m). Step 3: N-.3 (R,S)-2,3-Dihydro-l-(2-methylpropyl)-2-oxo-5- (thiazol-2-yl)-lH-l,4-benzodiazepin-3-vn-N -[3-(tetrazol-5- yl)phenyl]urea Triethylamine (193mg) was added to a stirred, cooled (0°C) suspension of 5-(3-aminophenyl)tetrazole hydrochloride (188mg) in anhydrous tetrahydrofuran (2ml). Triphosgene (93mg) was added followed by a further quantity of triethylamine (96mg) ensuring the pH > 7. The reaction mixture was stirred at ambient temperature for 30 minutes. A solution of 1,3-dihydro- 3(R,S)-amino-5-(thiazol-2-yl)-2H-l,4-benzodiazepin-2-one (254mg) in anhydrous tetrahydrofuran (1ml) was added and the mixture stirred for 2 hours. The reaction mixture was diluted with ethyl acetate (15ml) then acidified using 20% acetic acid. The organic layer was separated and the aqueous re-extracted with ethyl acetate (15ml). The combined organics were washed with brine, dried (sodium sulphate) then filtered and evaporated to dryness. The crude product was purified by column chr o m at o g r ap hy o n s il i c a u s ing dichloromethane/methanolacetic acid (95:5:0.5) to afford the title compound (12mg). mp 192°C (dec). R f = 0.65 in ethyl acetate/acetic acid (50:1) on silica plates; *H NMR (360MHz, dg- DMSO) δ 0.47 (3H, d, J = 6Hz); 0.68 (3H, d, J = 6Hz); 1.50-1.62 (IH, m); 3.64 (IH, dd, J τ = 6Hz, J 2 = 15Hz); 4.17 (IH, dd, J χ = 8Hz, J 2 = 15Hz); 5.38 (IH, d, J = 8Hz); 7.44-8.18 (11H, m); 9.34 (IH, s); MS, FAB+ mz 502 for (M+H) + . (Found: C, 55.71; H, 4.69; N, 24.15. C 2 H 2 3N 9 0 2 S.H 2 0 requires C, 55.48; H, 4.85; N, 24.26%). EXAMPLE 4A Tablets containing 1-25mg of compound Amount g Compound of formula (I) Microcrystalline cellulose Modified food corn starch Lactose Magnesium Stearate EXAMPLE 4B Tablets containing 26-100mg of compound Amount mg Compound of formula (I) Microcrystalline cellulose Modified food corn starch Lactose Magnesium Stearate The compound of formula (I) , cellulose, lactose and a portion of the corn starch are mixed and granulated with 10% corn starch paste. The resulting granulation is sieved, dried and blended with the remainder of the corn starch and the magnesium stearate. The resulting granulation is then compressed into tablets containing l.Omg, 2.0mg, 25.0mg, 26.0mg, 50.0mg and lOO g of the active compound per tablet. EXAMPLE 5 Parenteral injection Amount g Compound of formula (I) 1 to lOOmg Citric Acid Monohydrate 0.75mg Sodium Phosphate 4.5mg Sodium Chloride 9mg Water for injection to 1ml The sodium phosphate, citric acid monohydrate and sodium chloride are dissolved in a portion of the water. The compound of formula (I) is dissolved or suspended in the solution and made up to volume. T.YA PT.F _ Topical formulation Amount mg Compound of formula (I) 1-lOg Emulsifying Wax 30g Liquid paraffin 20g White Soft Paraffin to lOOg The white soft paraffin is heated until molten. The liquid paraffin and emulsifying wax are incorporated and stirred until dissolved. The compound of formula (I) is added and stirring continued until dispersed. The mixture is then cooled until solid. BIOLOGICAL ACTIVITY 1. CCK Receptor Binding (Pancreas) CCK-8 sulphated was radiolabelled with 125 I-Bolton Hunter reagent (2000 Ci/mmole) . Receptor binding was performed according to Chang and Lotti (Proc. Natl. Acad. Sci. 83_ . 4923-4926, 1986) with minor modifications. Male Sprague-Dawley rats (150-200g) were sacrificed by decapitation. The whole pancreas was dissected free of fat tissue and was homogenized in 25 volumes of ice- cold 10 mM N-2-hydroxyethyl-piperazine-N'-2-ethane sulphonic acid (HEPES) buffer with 0.1% soya bean trypsin inhibitor (pH 7.4 at 25°C) with a Kinematica Polytron. The homogenates were centrifuged at 47,800 g for 10 min. Pellets were resuspended in 10 volumes of binding assay buffer (20mM (HEPES)), _.___ ethylene glycol-bis-(0- aminoethylether-N,N'-tetraacetic acid) (EGTA) , 5mM MgCl2, 150 mM NaCl, bacitracin 0.25 mg/ml, soya bean trypsin inhibitor 0.1 mg/ml, and bovine serum albumin 2 mg/ml pH 6.5 at 25°C) using a Teflon (trademark) homogenizer, 15 strokes at 500 rpm. The homogenate was further diluted in binding assay buffer to give a final concentration of 0.5 mg original wet weight/1 ml buffer. For the binding assay, 50 μl of buffer (for total binding) or unlabelled CCK-8 sulphated to give a final concentration of 1 μM (for nonspecific binding) or the compounds of Formula I (for determination of inhibition of 125 I-CCK-8 binding) and 50 μl of 500 pM 125 I-CCK-8 (i.e. 50 pM final concentration) were added to 400 μl of the membrane suspensions in microfuge tubes. All assays were run in duplicate. The reaction mixtures were incubated at 25°C for 2 hours and the reaction terminated by rapid filtration (Brandell 24 well cell harvester) over Whatman GF/C filters, washing 3 x 4 mis with ice-cold 100 Mm NaCl. The radioactivity on the filters was counted with a LKB gamma counter. 2. CCK Receptor Binding (Brain) CCK-8 sulphated was radiolabelled and the binding was performed according to the description for the pancreas method with minor modifications. Male Hartley guinea pigs (300-500g) were sacrificed by decapitation and the cortex was removed and homogenized in 25 mL ice-cold 0.32 M sucrose. The homogenates were centrifuged at 1000 g for 10 minutes and the resulting supernatant was recentrifuged at 20,000 g for 20 minutes. The P2 pellet was resuspended in binding assay buffer (20mM HEPES, 5 mM MgCl 2 , 0.25 mg/ml bacitracin, 1 mM EGTA pH 6.5 at 25°C) , using a Teflon (trademark) homogenizer (5 strokes at 500 rpm) to give a final concentration of 10 mg original wet weight/1.2 ml buffer. For the binding assay, 50 μl of buffer (for total binding) or unlabelled CCK-8 sulphated to give a final concentration of 1 μM ( for nonspecific binding) or the compounds of Formula I (for determination of inhibition of 125 I-CCK-8 binding) and 50 μl of 500 pM 1 5 I-CCK-8 (i.e. final concentration of 50 pM) were added to 400 μl of the membrane suspensions in microfuge tubes. All assays were run in duplicate. The reaction mixtures were incubated at 25°C for 2 hours and then the reaction was terminated by rapid filtration (Brandell 24 well cell harvester) on Whatman GF/C filters with 3 x 5 ml washes of cold 100 mM NaCl. The radioactivity on the filters was counted with a LKB gamma counter. In Vitro Results Effects of the Compounds of Formula I on^^-I-CCK-δ receptor binding The preferred compounds of Formula I are those which produced dose-dependent inhibition of specific 1 5 I-CCK-8 binding as defined as the difference between total and non-specific (i.e. in the presence of 1 μM CCK) binding. Drug displacement studies were performed with at least 10 concentrations of compounds of Formula I and the IC5 0 values were determined by regression analysis IC5 0 refers to the concentration of the compound required to inhibit 50% of specific binding of 125 I-CCK-8. The data in Table I were obtained for compounds of Formula I. 10

Claims: CLAIMS : 1. A compound of formula (I) , or a salt or prodrug thereof: ( (i) wherein: one of W, X, Y or Z represents a nitrogen atom, another of W, X, Y or Z is a nitrogen, oxygen or sulphur atom or a group NR 8 where R 8 is H or Ci-galkyl, and the other two of W, X, Y and Z each independently represent nitrogen atoms or groups CR 8 , and the dotted circle represents two double bonds; R 1 represents C^-g alkyl, C- $ -η cycloalkyl, cyclopropylmethyl, (CE_2)qimidazolyl, (CH2)qtetrazolyl, (CH2)qtriazolyl, (where q is 1, 2 or 3) , CH2CO2R 5 (where R 5 is Cχ-4 alkyl) or a group CH 2 C0NR 6 R 7 (where R 6 and R 7 each independently represents H or Cι_4alkyl, or R 6 and R 7 together form a chain (CH2)p where p is 4 or 5) ; R 2 represents C1-6 alkyl, halo, (CH2) r tetrazolyl, optionally substituted in the tetrazole ring by C!_. 4 alkyl, (CH 2 ) r imidazol y 1 r C0NR 6 R 7 , SOtCx-ealkyl) , S0 2 (Ci-galkyl) , CONHS0 2 R 9 , S0 2 NHCOR 9 , SONHR 10 , cyano, B(0H)2 or (CH2)r C0 2 H ' where r is zero, 1 or 2, R 9 is Ci-galkyl, optionally substituted aryl, 2,2- difluorocyclopropane or trifluoromethyl, and R 10 is a nitrogen containing heterocycle; R 3 represents H, C- -Q alkyl or halo; is 0, 1 or 2; n is 0, 1, 2 or 3. 2. A compound as claimed in claim 1 wherein R 1 represents alkyl, 0 3 -7 cycloalkyl, cyclopropylmethyl, (CH 2 )q-imidazolyl (where q is 1 or 2), CH 2 C0 2 R 5 (where R 5 is Cχ- 4 alkyl) or a group CH 2 CONR 6 R 7 (where R 6 and R 7 each independently represents a hydrogen atom or a Cι_4 alkyl group, or R and R together form a chain (CH2)p where p is 4 or 5) ; and R 2 represents Cι_g alkyl, halo, (CH2)r~" tetrazol Yl (CH2)r~i m i dazo lyl cyclopropyl or a group (CH 2 )r c0 2 H where r is zero, 1 or 2; and m and n are both 1. 3. A compound as claimed in claim 1 or claim 2 wherein the substituent is imidazolyl, N-methylimidazolyl or thiazolyl. 4. A compound as claimed in any preceding claim wherein R 2 is C^-galkyl or COOH. 5. A compound as claimed in any one of claims 1 to 3 wherein R 2 is tetrazolyl. 6. A compound as claimed in claim 1 selected from: N-(3(R,S)-2,3-dihydro-l-methyl-5-(l-methylimidazol-2-yl)- 2-oxo-lH-l,4-benzodiazepin-3-yl)-N 1 -(3-methylphenyl)urea; N-(3(R,S)-2,3-dihydro-l-(2-methylpropyl)-2-oxo-5- (thiazol-2-yl)-1H-1,4-benzodiazepin-3-yl)-N 1 -(3- methylphenyl)urea; N-(3(R,S)-2,3-dihydro-l-(2-methylpropyl)-2-oxo-5- (thiazol-2-yl)-lH-l,4-benzodiazepin-3-yl)-N , -(3- (tetrazol-5-yl)phenyl)urea; and pharmaceutically acceptable salts and prodrugs thereof. 7. A compound as claimed in any preceding claim for use in therapy. 8. A process for the preparation of a compound as claimed in any one of claims l to 6 which process comprises reaction of an intermediate of formula (III) (III) wherein W, X, Y, Z, R 1 , R 3 and n are as defined for formula (I) , with an isocyanate of formula (IV) ( IV) wherein R 2 and m are as defined for formula (I) 9. A pharmaceutical composition comprising a compound as claimed in any one of claims 1 to 6 in association with a pharmaceutically acceptable carrier. 10. A method for the treatment or prevention of a physiological disorder involving CCK and/or gastrin, which method comprises administration to a patient in need thereof of a CCK and/or gastrin reducing amount of a compound according to claim 1. 11. A method as claimed in claim 10 for the treatment or prevention of anxiety. 12. A method as claimed in claim 10 for the treatment or prevention of panic. 13. A method as claimed in claim 10 for the treatment of pain.

Inventors: FLETCHER STEPHEN ROBERT, SHOWELL GRAHAM ANDREW, FLETCHER, STEPHEN, ROBERT, SHOWELL, GRAHAM, ANDREW
Applicants: MERCK SHARP & DOHME, MERCK SHARP & DOHME LIMITED
Application year: 1992
Main classification: C07D417
IPC codes: A61K31, A61P21, A61P25, C07D403, C07D417