GB1603407A - Hydantoin derivatives - Google Patents

Description

(54) HYDANTOIN DERIVATIVES (71) We, THE WELLCOME FOUNDATION LIMITED, of 183-193 Euston Road, London, N. W. I. a company incorporated in England do hereby declare that the invention for which we pray that a Patent may be granted to us and the method by which it is performed, to be particularly described in and by the following statement :- This invention relates to heterocyclic compounds, their synthesis, compositions containing them, and their use in medicine.

Hydantoin derivatives, defined hereinbelow in formula (I), have been found to have pharmacological properties related to those of natural prostaglandins, as demonstrated by their ability to mimic or antagonise the physiological effects of the natural prostaglandins in various biological preparations. In particular, certain compounds of formula (I) have been found to be potent mimetics of the antiplatelet aggregatory properties of prostaglandin E,.

In formula (I) :

Z is hydrogen or alkyl ; one of Z'and Z'is represented by the group-CH wherein X is phenylene,-C=-C-, cis or trans-CH=CH-or-CH2-CQZ in which each Q is independently selected from hydrogen and alkyl such as ethyl or the two Q's together form an alkylene radical having four, five or six carbon atoms; X'is a covalent bond or a straight or branched alkylene chain having I to 6 carbon atoms optionally having one of its methylene groups replaced by oxa (-O-) or thia (-S-) provided that at least one carbon atom separates the oxa or thia group from a-C=C-,-CH=CH-or-CO-group ; and XZ is selected from 5tetrazolyl, carboxyl, carbamoyl, hydroxymethvl and alkoxycarbonyl ; and the other of Z'and Z2 is represented by the group-Y-Y'-Y-Y' wherein Y is--CRZ CHZ in which each R is independently selected from hydrogen and methyl ; Y'is carbonyl, methylene substituted by hydroxy or methylene substituted by hydroxy and alkyl ; Y2 is a covalent bond or straight or branched alkylene having I to 7 carbon atoms optionally substituted on the carbon adjacent Y'by one or two groups each of which is alky or a cyclic radical, Y3 is hydrogen, hydroxy, alkoxy having I to 7, preferably 1 to 4, carbon atoms, a cyclic radical, phenyl, benzyl, phenoxy or benzyloxy, wherein each of phenyl, benzyl, phenoxy or benzyloxy may be substituted in the benzene ring by one or more groups selected from hydroxy, halo, nitro, amino, acylamino, alkenyl, alkoxy, phenyl, benzyloxy and alkyl which may itself be substituted by one or more halo groups; or y2 and Y3 together form an alkyl group having I to 7 carbon atoms of which at least one hydrogen is replaced by fluoro ; or Y is a covalent bond,-CH2-, or-CH,. CH2- and Y', y2 and Y3 taken together form a cycloalkyl or bicycloalkyl group substituted by a hydroxy group which preferably has three carbon atoms separating it from the hydantoin ring; provided that either (A) X'is or includes a thia group ; or (B) when the value of X'is other than as defined in (A), then (i) at least one of y2 and Y3 includes a cyclic radical other than cycloalkyl having from 3 to 10 carbon atoms, bicycloalkyl having from 4 to 10 carbon atoms, tetrahydrofuranyl or tetrahydropyranyl ; or (ii) Y is a bond,-CH,-or-CH,. CH,- and Y', Y'and Y'are taken together to form a hydroxy-substituted bicycloalkyl group ; or (iii) Y3 includes a benzene ring substituted by benzyloxy.

In the above definitions, the term'cyclic radical'means the monovalent radical derived by loss of a ring hydrogen atom from a monocyclic or polycyclic compound having from 3 to 12 ring atoms selected from carbon, nitrogen, oxygen and sulphur, which compound may be saturated or unsaturated and may be further substituted by one or more alkyl groups, but excluding phenyl. Such cyclic radicals include cycloalkyl having 3 to 10 carbon atoms such as cyclopropyl, cyclopentyl, cyclohexyl and cyclo-octyl, bicycloalkyl having 4 to 10 carbon atoms such as norbornyl (bicyclo [2,2,1 heptyl), spiroalkanyl having 5 to 12 carbon atoms such as 2-spiro [3,3] heptyl, I-spiro [4,4] nonane and 8-spiro [4,5] decane, adamantyl, cycloalkenyl having 4 to 10 carbon atoms such as 4-cyclopentenyl, heterocyclic radicals such as tetrahydrofuranyl and tetrahydropyranyl and heteroaryl radicals such as thienyl, furyl, pyridyl, pyrimidyl, thiazolyl, imidazolyl and diazepinyl.

Included in the term'cyclic radical'are those cyclic radicals wherein one or more hydrogen atoms are replaced by fluoro.

Unless otherwise stated, in formula (I) and other formulae in this specification, alkyE moieties are selected from methyl, ethyl, propyl, butyl, pentyl and hexyl, including all isomers thereof ; for example, in the definitions of Y'and Y'the alkyl groups are preferably methyl ; and the alkyl moiety of alkoxy-carbonyl is desirably methyl or ethyl. Similarly alkenyl groups have 2 to 4 carbon atoms for example vinyl.

In a compound of formula (I) the bonding of the divalent phenylene group of X may be ortho, meta or para, and the oxa or thia group is preferably adjacent the phenyl ring or when X is other than phenylene then X'may be-CHz-O-CHZ or-CH,-S-CH,-.

Included in the meaning of compounds of formula (1) are the salts corresponding to the carboxylic acids and tetrazoles when XI is carboxyl or tetrazolyl respectively, and the salts which may also be formed when Z is hydrogen.

Particularly valable salts for medical purposes are those having a pharmaceutically acceptable cation such as ammonium or that of an alkali metal, e. g. sodium and potassium, an alkaline earth metal, e. g. calcium and magnesium, or an organic base, particularly an amine such as ethanolamine. Salts having nonpharmaceutically acceptable cations are included within the ambit of this invention as useful intermediates to pharmaceutically acceptable salts, or the acids or esters of formula (I).

Except when there is clear indication to the contrary, formula (I) and other formulae in the specification embrace all stereoisomers represented therein. In particular such formulae include the enantiomeric forms, such mixtures as are designated racemates, and diastereoisomers.

The compounds of formula (I) may be synthesised by any method known in the art for the synthesis of compounds of analogous structure. For example, they may be prepared from the corresponding derivatives of hydantoic acid of formula (II) :

wherein G is carboxyl or a reactive derivative thereof such as an amide or an ester in particular an alkyl ester, and each of Z, Z'and Z2 has the same meaning as in formula (I), by cyclisation under acidic conditions or bv heating alone. The reaction may be effected in the absence of a solvent, but if desired an inert solvent may be used, for example a hydrocarbon such as petrol. Alternatively, where G is alkoxycarbonyl, cyclisation may be effected in the presence of a suitable base, for example an alkoxide such as sodium ethoxide.

Compounds of formula (II) are conveniently prepared from an amino acid derivative of formula (III) :

wherein G, Z'and Z2 are as defined in formula (I) provided that G may also be nitrile, by reaction with cyanic acid or an alkyl iso-cyanate depending respectively on whether Z is hydrogen or alkyl.

When cyanic acid is used, the cyanic acid is conveniently produced in situ by the use of an alkali metal cyanate, e. g. potassium cyanate, and an acid which may be present as an acid addition salt of the compound of formula (III) or a free acid of formula (III) wherein either or both of R and X2 is hydrogen. Alternatively an equivalent amount of mineral acid or an organic acid may be added to the reaction medium. The reaction may proceed in the absence of a solvent but desirably an inert solvent is used which is preferably polar such as water or a mixture of water with acetone dimethylformamide, dimethylsulphoxide or a lower alkanol such as ethanol or it may be a hydrocarbon, an ether or halogenated hydrocarbon such as chloroform. Where desired, for example if no solvent is used, the reaction may be promoted by heating the reactants.

Similar reaction conditions may be used when an alkyl iso-cyanate is used except that it is unnecessary to provide an equivalent amount of acid, as an acid addition salt or otherwise, in the reactants.

Instead of using a cyanate or isocyanate, a compound of formula (III) may be reacted with urea, nitrourea of an N-alkylurea as appropriate. A solvent is not essential but if desired an inert solvent such as one mentioned above may be used, and the reaction is preferably effected at an elevated temperature, for example from ! 00 C to 125 C, but temperatures up to 150 C may be employed.

In the above described synthesis, the intermediates of formula (II) need not be isolated from the reaction mixture and may be converted directly to compounds of formula (I) under the described reaction conditions.

An intermediate of formula (III) hay be conveniently prepared by reaction of a compound of formula (IV) with a compound of formula (V):

Q 2~Z2 (V) wherein G, Z'and Z2 are as defined in formula (III), one of Q1 and Q2 j5 amino and the other is halogeno, preferably bromo.. The reaction may be carried out by heating in the absence of solvent or in the presence of an inert solvent such as ethanol.

The intermediates of formula (III) wherein Z2 is-Y-Y'-Yz-Y'wherein Y' is carbonyl may also be prepared by reaction of an amine of formula (IV) wherein Q'is amino with an unsaturated ketone of formula (VI) : CRZ=CH. CO. Y2. Y' (VI) wherein y2 and Y3 have the same meaning as in formula (III) ; the reaction being effected in the presence or absence of an inert solvent, and at room temperature or optionally with heating.

Hydantoins of formula (I) may also be prepared by cyclisation of a compound of formula (VII) :

wherein Z, Z'and Z2 are as defined in formula (1) and G'is carboxyl or a reactive derivative thereof such as alkoxycarbonyl, e. g. ethoxycarbonyl.

Compounds of formula (VII) may be cyclise under similar conditions as for the cyclisation of a compound of formula (II) and conveniently the method used to prepare a compound of formula (VII) is chosen such that the prevailing reaction conditions permit spontaneous cyclisation.

For example, the intermediates of formula (VII) may be prepared by reacting a compound of formula (V) with a compound of formula (Vlll) : Qz~ Z2 (V)

wherein one of Q'and Q2 is halogeno, preferably chloro or bromo, and the other is amino and each ofZ, Z', Z and G'have the same meaning as in formula (VII). The reaction may be effected by admixture of the reactants or optionally an inert solvent is used and the mixture ts heated. Suitable solvents include alkanols, ethers, hydrocarbons and halogenated hydrocarbons.

The compounds of formula (VIII) may themselves be made by reacting an appropriate carbamic acid derivative, for example an alkyl ester, with a compound of formula (IV), using techniques known to those skilled in the art.

In a method related to those described hereinbefore, the hydantoins of formula (I) may be prepared by reacting a compound of formula (IX):

wherein each of Z, Z'and Z2 has the same meaning as in formula (1) with a carbonic acid derivative. Any carbonic acid derivative known to those skilled in the art as appropriate may be used, for example phosgene, diphenyl carbonate or an alkyl haloformate such as ethyl chloroformate. The reaction is desirably effected in the presence of a base, for example an amine such as triethylamine or di-iso-propyl ethylamine, and using an inert aprotic solvent such as toluene, dimethylformamide or an ether such as diethyl ether. The reaction may be carried out at room temperature but if desired the reaction mixture may be heated.

The intermediates of formula (IX) may be made using methods analogous to those described above for the preparation of compounds of formula (1TI).

The hydantoins of formula (I) wherein Z is alkyl may also be prepared by alkylation, using an alkylating agent which may be designated as a reactive ester derivative of an alcohol J3. OH, of a compound of formula (X) :

wherein J is hydrogen or alkyl, J'is hydrogen or Z', P is hydrogen or Z2 and J3 is alkyl) Z'or Z2, provided that one of J, J'and J'is hydrogen and J3 does not have the same value as J, J'or J2 ; in the definition of J', J2 and J3 each of Z'and Z2 has the same meaning as in formula (1). Suitable reactive ester derivatives include chloride, bromide, iodide and sulphonates such as p-toluenesulphonate, methanesulphonate and benzenesulphonate. The alkylation may be effected using reaction conditions which are known in the art to be suitable, for example in the presence of a base such as an alkali metal hydride, alkali metal amide, or alkali- metal alkoxide, typically sodium hydride or a sodium alkoxide, e. g. sodium methoxide.

The reaction is conveniently carried out in an inert solvent which simply acts as a dilueht for the reactants such as toluene, dioxan, ether, dimethyl-formamide, tetrahydrofuran, dimethylsulphoxide or acetonitrile or when the base is an alkali metal alkoxide then the corresponding alkanol may be used.

It will be appreciated that the intermediates of formula (X) wherein J is hydrogen are also compounds of formula (I) and may be prepared by one of the foregoing methods. The compounds of formula (X) may further be prepared by adaptation of methods already known in the art (see for example Chemical Reviews (1950) 46, p. 403-425).

A further preparation of compounds of formula (1) is by reduction of a corresponding unsaturated compound of formula (XI) :

wherein either Z'is =CR-CH2 Y'-YZ-Y'and Z"is-CHZ-X-X'-X or Z'is =CH-X-X'-Xz and Z is-Y-Y'-Y2-Y3 in which each of Z, R, X to X2 and Y to Y3 is as defined in formula (I), with a suitable reducing agent.

A suitable reducing agent is stannous chloride which may be used as an aqueous solution, optionally in the presence of dilute mineral acid, or captal tic hydrogenation may be effected in the presence of, for example, Raney nickel, platinum, palladium, ruthenium or rhodium. The choice of reducing agent in a given situation will of course be dictated by the presence of other reactive groups in the molecule which may themselves be susceptible to reduction.

The intermediates of formula (XI) may be prepared by the following series of reactions:

In the above formulae Z, Z3, Z4 and G have the same meaning as in formula (XI) and (III), G'is alkyl, for example n-butyl, and G'is halogeno such as bromo.

The formation of (XIII) is analogous to the ring closure involving a compound of formula (II) and compounds of formula (XIV) are prepared using concentrated mineral acid such as hydrochloric acid.

Tetrazoles of formula (I) may be prepared from corresponding compounds wherein the group-X2 is replaced by

wherein X3 and X'together form a bond (nitrile), X3 is hydrogen or alkyl and X'is alkoxy (imidoester), alkylthio (imidothioester), NHNH2 (amidrazone), or amino (amidine) or X3 is hydroxy and XI is amino (amidoxime). The reaction is preferably carried out in a polar aprotic liquid medium such as dimethylformamide using a salt of hydrazoic acid, e. g. sodium azide. However, when X2 is replaced by an amidine or amidrazone, a suitable reagent is nitrous acid. If an amidine is reacted with nitrous acid then reduction of the intermediate nitrosation product, with or without prior isolation, using, for example, sodium amalgam is required to give the corresponding tetrazole. The tetrazole precursor may be obtained by well known methods, for example the nitrile may be obtained by dehydration of the corresponding amide.

The alcools of formula (I) wherein XI is hydroxymethyl may also be obtained by reduction with an appropriate reducing agent of the corresponding acid, ester, acid halide, acid anhydride or aldehyde. The appropriate reducing agent will depend on the particular substrate, but a reactant which may be used is sodium in ethanol. In particular a carboxylic acid may, for example, be converted to a corresponding mixed anhydride with ethyl chloroformate in the presence of a base such as triethylamine, and subsequently reduced to the alcohol using sodium borohydride. Similarly an ester may be reduced to the alcohol using di-iso-butyl aluminium hydride in an inert solvent such as ether or hydrocarbon such as hexane or benzene. Such alcohols may also be prepared by catalytic hydrogenation.

Alternatively the alcools of formula (I) wherein XI is hydroxymethyl may be prepared by hydrolysis of a corresponding halide with an appropriate reagent. For this purpose a hydroxide may be used, for example, an aqueous alkali or a suspension of silver oxide in water.

In the synthesis of hydantoins of formula (I) having a hydroxyl group in a side chain it may be desirable to protect this during the course of the reaction. This may be readily effected in known manner using a protecting group such as acyl, aroyl, tetrahydropyran-2-yl, I-ethoxyethyl or aralkyl, for example benzyl.

Removal of protecting groups may be carried out by appropriate methods known to those skilled in the art: for example an acyl group may be removed by acid or base hydrolysis, and a benzyl group by reductive cleavage.

Furthermore a ketone of formula (1) wherein Y'is carbonyl may be converted to the corresponding secondary alcohol by reduction with a suitable reducing agent, such as sodium borohydride. Aiso, an alcohol of formula (1) wherein Y'is -CH. OH- may be oxidised to the corresponding ketone using Jones'reagent, acid dichromate or any other suitable reagent.

Similarly where the compounds of formula (I) have a C=C or CH=CH bond these may be converted by conventional hydrogenation techniques, for example using a Lindlar type. or Adams catalyst, to the corresponding ethylenic or saturated compounds as appropriate.

The hydantoins of formula (I) have an asymmetric 5-carbon atom, and a further asymmetric centre is present in those compounds wherein Y'includes a hydroxyl group. Such alcohols therefore exist as four isomers which are separable by thin layer chromatography or high performance liquid chromatography into two diastereomers, each of which is a racemic mixture of two isomers. On separation of the diastereomers, one diastereomer may be converted to a mixture of the four isomers by treatment with a base, such as an alkali metal hydroxide, and subsequently re-separated to provide two diastereomers. Repeated use of this technique enables the effectua conversion of one diastereomer to the other ; this may be desirable when one diastereomer has a biological activity preferred to the other, for example, the less polar diastereomer of the compounds of formula (I).

The corresponding alcools of formula (III) also exist m four isomeric forms.

If desired, these may be separated into two epimers and subsequent cyclisation to a compound of formula (I) retains the stereochemical configuration.

In all of the foregoing chemical procedures it is of course evident that the choice of reactant will be dictated in part by the functional groups present in the substrate, and where necessary reactants having an appropriate selectivity of action must be used.

The hydantoins of formula (I) are of value in having pharmacological properties related to those of natural prostagtandins that is, the hydantoins mimic or antagonise the biological effects of members of the prostaglandin (PG)'A','B', 'C','D','E'and'F'series. For example, hydantoins of formula (I) have been found to mimic the antiaggregatory effect of PGE, on blood platelets, and to antagonise the contraction induced by PGE2 or PGF2 on smooth muscle taken from the rat stomach, rat colon, chick rectum and guinea pig trachea. In general, antagonistic properties, as opposed to mimetic, have been observed when using larger doses of the hydantoins. The pharmacological profile, by which is meant the relative activities, mimetic or antagonistic, compared with the natural prostaglandins, will of course vary depending on the specific hydantoin under consideration.

By reason of their prostaglandin-related properties, the hydantoins of formula (I) are useful in the pharmacological characterisation and differentiation of the biological activities of the natural prostaglandins and their"receptors". The further understanding of the physiological role of prostaglandins is of course valable in the search for new and improved therapeutic substances.

The hydantoins of formula (I) are also of value as therapeutic agents. In particular hydantoins such as those described previously as having a potent antiaggregatory effect on blood platelets are useful whenever it is desired to inhibit platelet aggregation or to reduce the adhesive character of platelets, and may be used to treat or prevent the formation of thrombi in mammals, including man. For example, the compounds are useful in the treatment and prevention of myocardial infarcts, to treat and prevent thrombosis, to promote patency of vascular grafts following surgery, and to treat complications of arteriosclerosis and conditions such as antherosclerosis, blood clotting defects due to lipermia, and other clinical conditions in which the underlying aetiology is associated with lipid imbalance or hyperlipidemia. A further use for such compounds is as an additive to blood and other fluids which are used in artificial extra-corporeal circulation and perfusion of isolated body portions.

A group of compounds which are particularly valuable as inhibitors of platelet aggregation are those of formula (I) wherein Z is hydrogen ; Z'is carboxyalkyl or carboxyalk-2-enyl wherein the alkylene or alkenylene moiety has 3 to 9, preferably 6, carbon atoms; and Z2 j5 a group- (CH2) 2. CH. OH. Y2. Y3 wherein y2 is a bond or branched alkylene having a tertiary carbon atom adjacent the hydroxy-substituted carbon and Y'is as defined in formula (I).

Within this group of compounds, those wherein Z'is carboxyhexyl and Y3 is cycloalkyl having 4 to 7 carbon atoms are especially active.

The hydantoins of formula (I) also cause relaxation of vascular smooth muscle in a similar way as do members of the prostaglandin'A'and'E'series. Compounds relaxing vascular smooth muscle are capable of inducing vasodilation and therefore have anti-hypertensive properties and are useful in lowering the blood pressure in mammals, including man, and may be used alone or in combination with a A- adrenoceptor blocking agent or another antihypertensive substance for the treatment of all grades of hypertension including essential, magnant and secondary hypertension.

The compounds of formula (I) also mimic the effect of PGE, of antagonising histamine induced broncho-constriction. Compounds (I) having this property may be used in the treatment or prophylaxis of bronchial asthma and bronchitis by alleviating the bronchoconstriction associated with this condition.

Hydantoins of formula (I), which inhibit pentagastrin-induced gastric acid secretion and reduce the formation of aspirin-induced gastric lesions in rats are useful in reducing excessive gastric secretion, reducing and avoiding gastrointestinal ulcer formation and accelerating the heating of such ulcers already present in the gastrointestinal tract whether such ulcers arise spontaneously or as a component of poly-glandular adenoma syndromes.

Intravenous infusions of hydantoins of formula (I) to dogs increase the urine volume indicating a potential utility for such compounds as diuretic agents, the uses of which include the treatment of oedema, for example oedema associated with heart failure, liver failure or kidney failure in man or other mammals.

A further use for hydantoins of formula (I) which mimic the uterine smooth muscle effects of PGE2 and PGF,, is as antifertility agents, in particular as abortifacients.

In addition the compounds of formula (1) may be used in the treatment of proliferative skin diseases such as are associated with excessive cell division in the epidermis or dermis which may be accompanied by incomplete cell differentiation.

Particular conditions which may be alleviated include psoriasis, atopic dermatitis, nonspecific dermatitis, primary irritant contact dermatitis, allergic contact dermatitis, basal and squamous cell carcinomas of the skin, lamellar icthyosis, epidermolytic hyperkeratosis, premalignant sun induced keratosis, non malignant keratosis, acne, and seborrheic dermatitis in humans and atopic dermatitis and mange in domestic animas. For the treatment of these conditions the compounds are desirably applied topically to the affected skin. Alternatively they may be administered by an intradermal or intramuscular injection which may be directly into the skin lesion or into the surrounding tissue. Injectable compositions will generally contain from 0.1 to 0.5% w/v of active ingredient.

The amount of a compound of formula (I) required to achieve the desired biological effect will of course depend on a number of factors, for example, the specific compound chosen, the use for which it is intended, the mode of administration, and the recipient. In general, a daily dose may be expected to lie in the range of from l, ug to 20mg per kilogram bodyweight. For example, an intravenous dose may lie in the range of from 5, ug to I mg/kg which may conveniently be administered as an infusion of from 0. 01 to 50, ug per kilogram per minute. Infusion fluids suitable for this purpose may contain from 0. 001 to 100, for example from 0. 01 to 10, ug per millilitre. Unit doses mamy contain from 10 yg to IOOmg of a compound of formula (I), for example ampoules for injection may contain from 0.01 to Img, and orally administrable unit dose formulations such as tablets or capsules may contain from 0. 1 to 50, for example 2 to 20, mg.

More specifically, when a compound of formula (I) is used to inhibit platelet aggregation it is generally desirable to achieve a concentration in the appropriate liquid, whether it be the blood of a patient or a perfusion fluid, of about I Mg to lOmg, for example from lO, to) mg, per liter.

The abovementioned doses refer to the acids, amides, esters, alcools and tetrazoles of formula (1) ; where a salt is used, the dose should be taken as referring to the corresponding anion.

For use in the treatment or prophylaxis of the conditions referred to above, while the hydantoin compounds may be used as the raw chemical they are preferably presented with a pharmaceutically acceptable carrier therefor as a pharmaceutical formulation. The carrier must of course be'acceptable'in the sense of being compatible with the other ingredients of the formulation and not deleterious to the recipient thereof. The carrier may be a solid or a liquid, and is preferably formulated with a hydantoin compound as a unit-dose formulation, for example a tablet, which may contain from 0.05% to 95% by weight of the hydantoin compound. Other pharmacologically active substances may also be present in formulations of the present invention as indicated above. The hydantoin compounds may be incorporated in the formulations either in the form of the acid or the salt or ester thereof, and the formulations may be prepared by any of the well-known techniques of pharmacy consisting essentially of admixture of the components of the formulation.

The formulations include those suitable for oral, rectal, topical (buccal-e. g. sub-lingual), or parenteral (that is subcutaneous, intramuscular and intravenous) administration, although the most suitable route in any given case will depend on the nature and severity of the condition being treated, and on the nature of the hydantoin compound.

Formulations suitable for oral administration may be presented as discrete units such as capsules, cachets, lozenges or tablets each containing a predetermined amount of hydantoin compound ; as a powder or granules ; as a solution or a suspension in an aqueous liquid or a nonaqueous liquid ; as an oil-inwater mulsion ; or as a water-in-oil liquid mulsion. Such formulations may be prepared by any of the methods of pharmacy but all methods include the step of bringing into association the hydantoin compound with the carrier which constitutes one or more accessory ingredients. In general they are prepared by uniformly and intimately admixing the hydantoin compound with liquid or finely divided solid carriers or both, and then, if necessary, shaping the product into the desired presentation. For example, a tablet may be prepared by compression or moulding a powder or granules of the hydantoin compound, optionally with one or more accessory ingredients. Compressed tablets may be prepared by compressing, in a suitable machine, the hydantoin compound in a free-flowing form such as a powder or granules optionally mixed with a binder, lubricant, inert diluent, or surface active or dispersing agent (s). Moulded tablets may be made by moulding in a suitable machine the powdered hydantoin compound moistened with an inert liquid diluent.

Formulations suitable for buccal (sub-lingual) administration include lozenges comprising a hydantoin compound in a flavoured basis, usually sucrose and acacia or tragacanth; and pastilles comprising a hydantoin compound in an inert basis such as gelatin and glycerin ; or sucrose and acacia.

Formulations suitable for topical applications to the skin preferably take the form of an ointment, cream, lotion, paste, gel, spray, aerosol composition or oil.

Carriers which may be used include Vaseline (Trade Mark), lanoline, polyethylene glycols, alcohols and combinations thereof. The active ingredient is generally present in a concentration of from 0.1 to 15% w/w of the composition, for example from about 0.5 to about 2%.

Formulations of the present invention suitable for parenteral administration conveniently comprise sterile aqueous preparations of a hydantoin compound, which preparations are preferably isotonic with the blood of the intended recipient.

These preparations are preferably administered intravenously, although administration may also be effected by means of subcutaneous or intramuscular injection. Such preparations may be conveniently prepared by admixing the hydantoin compound with water and rendering the product sterile and isotonic with the blood.

Formulations suitable for rectal administration are preferably presented as unit-dose suppositories.

These may be prepared by admixture of the hydantoin compound with one or more of the conventional solid carriers, for example cocoa butter, and shaping of the resulting mixture.

It will be appreciated from the foregoing that what we will claim may comprise: (a) The novel compounds of formula (I) as hereinabove defined.

(b) A method for the preparation of the novel compounds of formula (I) as hereinabove described.

(c) A pharmaceutical formulation comprising a compound of formula (I) in association with a pharmaceutically acceptable carrier therefor, and methods for the preparation of such formulations.

(d) A method for lowering blood pressure in a mammal, excluding man, which comprises administration to the mammal of an effective hypotensive, non-toxic amount of a compound of formula (I).

(e) A method for the treatment or prophylaxis of thrombosis in a mammal or mammalian tissue, excluding human, which comprises administration of a nontoxic, effective anti-thrombotic amount of a compound of formula (I).

(f) A method for inducing vasodilation in a mammal, excluding man, comprising administration to said mammal of a non-toxic, effective vasodilatory amount of a compound of formula (I).

(g) A method for inducing bronchodilation in a mammal, excluding man, comprising administration to said mammal of a non-toxic, effective bronchodilatory amount of a compound of formula (I).

(h) A method of inhibiting the aggregation of platelets which comprises the bringing of said platelets into association with an effective platelet aggregation inhibitory amount of a compound of formula (1), other than by administration of said compound to man.

The following Examples (other than the Reference Preparations) are provided by way of illustrating the present invention, but not constituting a limitation thereof. The compounds prepared in the Reference Preparations do not constitute a part of the present invention. The Reference Preparations merely provide detailed exemplification of methods which may be used to prepare the compounds of the Examples. All temperatures are given in degrees Celsius.

Reference Preparation I Preparation of 5- (6-Carboxylhexyl)-1- (3-hydroxy-4, 4-dimethyl 5-phenylpentyl) hydantoin A. Diethyl 2-aminononane-1, 9-dioate Diethyl acetamidomalonate (16. 7g) and ethyl 7-bromoheptanoate (16. 6g) were dissolved in ethanolic sodium ethoxide (prepared from sodium (1. 5 I g) and absolute ethanol (30 ml) and the mixture was refluxed for 27 hours. The cooled solution was poured into ice-water, the product was extracted into ether, and the dried extract was evaporated to give crude diethyl acetamido- (6-ethoxy carbonylhexyl) malonate as a pale yellow oil, 2. 2 (3H, singlet,-COCH,), 4. 17 (6H, multiplet, 3x-OCHz-CH3. This amide was refluxed with concentrated hydrochloric acid (I I l ml) for Si hours, the cooled solution was washed with ether, and the aqueous layer was decolourised with activated charcoal and evaporated to dryness in vacuo. The residual colourless glass was dissolved in the minimum quantity of absolute ethanol and added dropwise to a stirred, cooled (-10 C) mixture of absolute ethanol (125 ml) and thionyl chloride (15. 7 g). The resulting solution was set aside at room temperature for I hour, refluxed for 1 hours, cooled, and poured into ice-water, adjusting the pH to 9 with aqueous sodium hydroxide. The mixture was extracted with ether, and the dried extract was concentrated and distille, giving diethyl 2-amino-nonane-1, 9-dioate (55 0 yield) as a colourless oil, b. p. 114-115'/0. 02-03 mm.

B. Diethyl 2-((4, 4-dimethyl-3-oxo-5-phenylpentyl) amino) nonane-I, 9-dioate To diethyl 2-aminononane-1, 9-dioate (5.18 g) was added dropwise 4,4 dimethyl-5-phenylpent-I-en-3-one (3.95 g) with cooling and stirring. The mixture was allowed to stand at room temperature for 21 hours to give diethyl 2- (4,4-dimethyl-3-oxo-5-phenylpentyl) amino) nonane-1, 9-dioate.

C. Diethyl 2- (3-hydroxy-4, 4-dimethyl-5-phenylpentyl) amino) nonane-1,9-dioate The foregoing crude ketone (5. 1 g) was dissolved in absolute ethanol (70 mi) and the solution was stirred in an ice-bath during the gradual addition of sodium borohydride (380 mg). The solution was stirred in the ice-bath for a further 10 minutes and then left to stand at room temperature for 5 hours. Most of the alcohol was evaporated, water was added, and the solution acidified to pH 6. The insoluble oil was extracted with ether, and the ether solution was dried and evaporated to leave diethyl 2- (3-hydroxy-4,4-dimethyl-5-phenylpentyl) amino) nonane 1, 9-dioate as a pale yellow oil which was used without further purification.

D. 5- (6-Ethoxycarbonyl-hexyl)-1- (3-hydroxy-4, 4-dimethyl-5- phenylpehtyl) hydantoin and the corresponding acid A solution of the above alcohol (8.45 g) in ethanol (37.6 ml) and 2Nhydrochloric acid (18. 8 ml) was stirred and cooled in ice during the dropwise addition of a solution of potassium cyanate (3.05 g) in water (5.6 ml). The mixture was allowed to stand at room temperature for 18 hours, then the alcohol was evaporated, water was added and the insoluble oil was extracted with ether. The dried ether solution was evaporated to leave a viscous oil which was heated on the steam bath for 6 hours to give 5- (6-ethoxy-carbonylhexyl)-I- (3-hydroxy4,4-dimethyl-5-phenylpentyl)-hydantoin as a viscous pale yellow oil.

This ester was added to a mixture of 2N-sodium hydroxide (25 ml) and water (60 ml) and the resulting cloudy solution was left at room temperature for 2 hours.

The solution was washed with ether and the clear alkaline solution was acidified with 2N-hydrochloric acid and the precipitated oil was extracted with ether.

Evaporation of the dried ether solution gave a viscous oil (6.8 g) which was chromatographed on a column of silica gel to give 5- (6-carboxyhexyl)-I- (3hydroxy-4,4-dimethyl-5-phenylpentyl) hydantoin as a colourless viscous oil which solidified, m. p. ca. 115 C, shrinking from ca. 90 C, being a mixture of diastereomers. Recrystallisation several times from a mixture of ethyl acetate and light petroleum (b. p. 60-80 C) gave one of the diastereomers as small needles, m. p. 135-137 C.

Reference Preparation 2 Preparation of 5- (6-Carboxyhexyl)-I- (3-hydroxyoctyl) hydantoin A. Diethyl 2- (3-tetrahydropyran-2-yloxy) octylamino) nonane-1, 9-dioate Dry ethereal hydrogen bromide, prepared from ether (200 ml) and hydrogen bromide (26.8 g) at 0 C, was added dropwise to a stirred solution of acrolein (19. 15 g) in ether (f00 ml) cooled to-25 C. The stirred mixture was kept at this temperature for I hour, allowed to come to 0 C, stirred for I hour, at 0 C and then added dropwise to ethereal pentyl magnesium bromide (prepared from 1bromopentane (54 g) magnesium (8.8 g) and ether (120 ml)), maintaining constant reflux. The reaction mixture was decomposed with saturated aqueous ammonium chloride and extracted with ether, and the dried extract was concentrated and distille, giving I-bromo-3-hydroxyoctane as a colourless oil, b. p. 68.572.5 C/0.08 mm. A solution of this bromo-alcohol (20. 9 g) in dihydropyran (17. 0g), was treated with p-toluenesulphonic acid (500 mg) in a little ether, set aside at room temperature for 18 hours, and washed with aqueous sodium bicarbonate. The organic layer was percolated through silica in 1 : 9 ether/hexane and the solvent was removed in vacuo, giving I-bromo-3- (tetrahydropyran-2-yloxy) octane as a colourless oil, 0. 88 (3H, triplet, CH3) and 4.62 (I H, broad,-O-CHR-O-). A solution of this tetrahydropyranyl intermediate (15. 0 g) and diethyl 2 aminononane-I, 9-dioate (13. 0 g) in absolute ethanol (100 ml) was refluxed for 18 hours, the ethanol was removed in vacuo, and the residue was diluted with water containing a slight excess of sodium carbonate based on the theoretical yield of hydrobromide produced. The mixture was extracted with dichloromethane, the extract was dned over sodium sulphate and evaporated, and the residue was purified by column chromatography on silica in ! : 4 hexane/ether, giving diethyl 2 (3- (tetrahydropyran-2-yloxy) octylamino) nonane-1, 9-dioate as a colourless viscous oil, 0. 88 (3H, triplet-CH3), 2.28 (2H, triplet,-CH2-COZEt), 2.61 (2H, muftip (et,-CHZ-N), 3. 20 (1H, triplet, N-CHR-CO2Et), 4. 13 (4H, multiplet, 2xOCH2CH3), 4.60 ( H, broad-O-CHR-O-).

The above aminodiester was alternatively prepared in the following manner.

Diethyl 2-aminononane-1, 9-dioate (10. 40 g) and oct-I-en-3-one (5.04 g) were mixed slowly at 0 C. with stirring, and set aside at room temperature for 3 hours, giving diethyl 2- (3-oxooctylamino) nonane-1, 9-dioate as a colourless oil, 52. 3 (4H, multiplet,-CHz-COZEt) and NCH2CH2CO), 3.16 (IH, triplet, EtO2CCHRN), 4.11 (2H, quartet,--O-CH2-CH,), 4. 17 (2H, quartet,-0- CH2CH3). A stirred solution of this ketone (13. 5 g) in absolute ethanol (140 ml) was treated dropwise at 0 C with sodium borohydride (665 mg) in absolute ethanol (70 ml), then kept for 3+ hours at room temperature, and concentrated at 40 C in vacuo. The residue, dissolved in water, was brought to pH5 with N-hydrochloric acid and extracted thoroughly with chloroform, the extract was washed with water, dried, and evaporated, giving diethyl 2- (3-hydroxy-octylamino) nonane-1, 9 dioate as a cofouriess oil. Without further purification, the latter was dissolved in dihydropyran (14. 0 ml), treated with ether (10 ml) followed by p-toluenesulphonic acid (6.72 g) in portions, and set aside at room temperature for 18 hours. The reaction solution was diluted with ether, washed with aqueous sodium carbonate and then water, dried, and evaporated, and the residue was purified by column chromatography on silica in 1: 4 hexane/ether, giving diethyl 2- (3 (tetrahydropyran-2-yloxy) octylamino) nonane-1, 9-dioate, identical (n. m. r., i. r. mixed t. l. c.) with that prepared previously.

B. 5- (6-Carboxylhexyl)-1- (3- (tetrahydropyran-2-yloxy) octyl) hydantoin To a solution of diethyl 2- (3- (tetrahydropyran-. 2 yloxy) octylamino) nonane-1, 9-dioate (7.8 g) in ethanol (32 ml) was added a solution of potassium cyanate (3.0 g) in water (6 ml). The resulting suspension was stirred and cooled during the gradual addition of 2N-hydrochloric acid (16. 7 ml).

The solution was allowed to stand at room temperature for 22 hours, most of the ethanol was evaporated, water was added, and the insoluble oil was extracted with ether. The ether solution was washed with water, dried over magnesium sulphate, and evaporated. The yellow oil so obtained (8.0 g) was dissolved in light petroleum (b. p. 60-80 C) and the solution was refluxed for 4 hours, evaporated to dryness, and the residual oil was heated on the steambath for 2 hours to give 5- (6 ethoxycarbonylhexyl)-I- (3- (tetrahydropyran-2-yloxy) octyl) hydantoin as a yellow oil (7.3 g) which was used without further purification.

A solution of the ester (6.2 g) in 0. 5N-sodium hydroxide solution (80 ml) was allowed to stand at room temperature for 24 hours after which the solution was washed with ether, the aqueous layer was acidified with 2N-hydrochloric acid, and the precipitated oil was extracted with ether. The washed and dried ether extract was evaporated to give 5- (6-carboxyhexyl)-I- (3- (tetrahydropyran-2yloxy) octyl) hydantoin as a yellow oil.

C. 5- (6-Carboxyhexyl)-1- (3-hydroxyoctyl) hydantoin This tetrahydropyranyloxy compound (3.55 g) was dissolved in tetrahydrofuran (28 ml) and 5N-hydrochloric acid (7 ml) and the solution was left at room temperature for 3+ hours, and then refluxed for 30 minutes. Most of the solvent was evaporated, water was added and the insoluble oil was extracted with ether. The ether solution was washed with water, dried over magnesium sulphate and evaporated to give 3.15 g of viscous yellow oil. The oil was purified by chromatography on a column of silica gel, elution first with chloroform and then with a mixture of chloroform and methanol (19 : 1) giving 5- (6-carboxyhexyl) I- (3-hydroxyoctyl) hydantoin as a very viscous almost colourless oil, 0. 89 (3H, triplet,-CH3), 2.34 (2H, triplet, H), 2.9-4.2 (4H, complex,-CH2- N, CH-N, CH-OH), ca. 5.6 (2H, broad, exchangeable,-CO, H,-OH), ca. 9.0 (IH, broad, exchangeable, NH).

Using the method of Reference Preparation I the above identified hydantoin was also prepared via the corresponding diethyl 2- (3-hydroxyoctyl) amino)nonane-1, 9-dioate.

D. Separation of Diastereomers The hydantoin resulting from the above described preparation was a viscous oil which by use of High Pressure Liquid Chromatography (HPLC) on a column of silica with a mixture of chloroform, methanol and acetic acid (97 : 2.5: 0.5) as solvent was separated into diastereomers, both of which formed small colourless needles of m. p. 76-78 C and 63-65 C respectively.

The same diastereomers were prepared by cyclisation of the corresponding diastereomers of formula (III). That is, the mixture of diastereomers of diethy 2- [ (3-hydroxyoctyl) amino] nonane-1, 9-dioate, prepared as in Reference Preparation 1, was dissolved in ethanol and an ethereal solution of hydrogen chloride was added. The solution was evaporated to dryness to leave the mixture of diastereomeric hydrochlorides as a viscous oil, which partly solidifie on standing.

Ether was added and the mass stirred and cooled to give a crystalline solid, which was collecte, washed with ether, and dried. The solid was crystallized from ethyl acetate to give small colourless plates, m. p. 95-96. 5 , of a pure hydrochloride.

This salt was suspended in dilute sodium hydroxide solution and shaken with ether, and the separated ether solution was washed, dried and evaporated to give one of the diastereomers (A) of diethyl 2- [ (3-hydroxyoctyl) aminolnonane-1, 9dioate as a colourless oil.

The ether filtrate remaining after collection of the original solid hydrochloride was evaporated to leave an oily hydrochloride, which was converted to the base as described above to give the almost pure second diastereomer (B) of diethyl 2 [ (3-hydroxyoctyl) amino] nonanedioate as a colourless oil.

By the method described in Reference Preparation 1, the above diastereomer (A) was converted into a single diastereomer of 5- (6-carboxyhexyl)-I- (3hydroxyoctyl) hydantoin, which crystallised from a mixture of ethyl acetate and light petroleum (b. p. 60-80 ) as small colourless needles, m. p. 63-65 .

Similarly the above diastereomer (B) was converted into the second diastereomer of 5- (6-carboxyhexyl)-I- (3-hydroxyoctyl) hydantoin, which crystallised from ethyl acetate-light petroleum (b. p. 60-80 ) as small colourless needles, m. p. 76-78 .

E. Interconversion of the diastereomers A solution of 5- (6-carboxyhexyl)-I- (3-hydroxyoctyl) hydantoin (diastereomer of m. p. 76-78 ) (100 mg) in N-sodium hydroxide solution (3 ml) was allowed to stand at room temperature for 19 hours. The solution was acidified and extracted with ether, and the ether extract was washed with water, dried and evaporated to leave a viscous oil. By means of high performance liquid chromatography this oil was separated into the two diastereomers of 5- (6 carboxyhexyl)-I- (3-hydroxyoctyl) hydantoin, m. p. 76-78 C, identical with the starting material (ca. 40 mg) and m. p. 63-6S C (ca. 40 mg), identical with the diastereomer (A) described above.

In similar fashion, the diastereomer of m. p. 63-65 C was converted into a mixture of approximately equal quantities of itself with the diastereomer of m. p.

76-78 C, and the pure diastereomers were isolated by means of high performance liquid chromatography.

Examples I to 5 Using the method of the preceding Reference Preparations were prepared :- I a) diethyl 2- ( (3-oxo-3- (2-thienyl) propyl) amino) nonante-1, 9-dioate ; 2a) diethyl 2- ((3-oxo-3- (2-furyl) propyl) amino) nonane-1, ; 3a) diethyl 2- ((3-oxo-3- (cyclopent-3-enyl) propyl) amino) nonane1,9-dioate; 4a) diethyl 2- ((norbornan-2-on-3-ylmethyl) amino) nonane-1, 9dioate; and 5a) ethyl 2- ( (3-oxo-3-cyclohexylpropyl) amino)-6- (ethoxycarbonylmethylthio) hexanoate; and thence: lb) diethyi 2- ((3-hydroxy-3- (2-thienyl) propyl) amino) nonane-1, 9dioate ; 2b) diethyl 2- ( (3-hydroxy-3- (2-furyl) propyl) amino) nonane-1, 9- dioate ; 3b) diethyl 2- ( (3-hydroxy-3- (cyclopent-3- enyl) propyl) amino) nonane-1, 9-dioate; 4b) diethyl 2- ((2-hydroxy-norbornan-3-ylmethyl) amino) nonane-1, 9dioate ; and 5b) ethyl 2- ( (3-hydroxy-3-cyclohexylpropyl) amino-6- (ethoxycarbonyl-methylthio) hexanoate; from which were obtained the following hydantoins which, where possible, were separated to provide individual diastereomers having the stated characteristics: I c) 5- (6-carboxyhexyl)-I- (3-hydroxy-3- (2thienyl) propyl) hydantoin, 78-80 C ; 2c) 5- (6-carboxyhexyl)-l- (3-hydroxy-3- (2-furyl) propyl) hydantoin; 3c) 5- (6-carboxyhexyl)-I- (3-hydroxy-3- (cyclopent-3- enyl) propyl) hydantoin, 86-87 C ; 4c) 5- (6-carboxyhexyl)-I- (2a-hydroxynorbornan-3- ylmethyl) hydantoin, 103-107 C, 132-136 C ;. and 5c) 5- (4-carboxymethylthiobutyl)-I- (3-hydroxy-3- cyclohexylpropyl)-hydantoin, 104-108 C.

The starting substance for Example 5, diethyl 2-amino-7-thia-nonane- 1, 9-dioate, was prepared as follows : Diethyl 4-bromobutylacetamidomalonate (Rev. Trav. Chim., 1971, 874) (35.2 g) was dissolved in absolute ethanol (150 ml) and a solution of ethyl mercaptoacetate (12. 0 g) in ethanolic sodium ethoxide (from 2.30 g sodium and 130 ml ethanol) added dropwise with stirring. A slight exotherm soon subsided, and the resulting cloudy mixture was stirred at room temperature for 24 hours. The mixture was evaporated to low bulk in vacuo, then diluted with water and extracted with chloroform. The dried extract was evaporated, giving diethyl acetamido- (4ethoxycarbonylmethylthio) butyl malonate (42.2 g) as a colourless gum. This was suspended in 10% aqueous hydrochloric acid (750 ml) and refluxed for 3 hours, cooled, then evaporated to low bulk in vacuo, using ethanol to remove the last traces of water azeotropically. The residual gum was dissolved in a little ethanol and added to a solution of thionyl chloride (21.0 ml) and ethanol (300 ml) (made up at-10 C) and the solution stood at +5 C for 18 hours, then refluxed for I hour.

The cooled solution was evaporated, and the residue partitioned between chloroform and water and the aqueous layer taken to pH ~10 with sodium carbonate solution. The aqueous layer was extracted throughly with chloroform and the combined extracts dried and evaporated, giving diethyl 2-amino-7- thia-nonane-1, 9-dioate (25.5 g) as a pale yellow oll.

Examples 6 to 10 Also prepared by the method of Reference Preparation I : 6a) ethyl 2- ( (3-oxo-3-cyclohexylpropyl) amino)-5 (ethoxycarbonylmethylthio) pentanoate; 7a) ethyl 2- ( (3-oxo-3-cyclohexylpropyl) amino)-6 (ethoxycarbonylmethylthio) hex-4Z-enoate; 8a) ethyl 2- ( (3-oxo-3-cyclohexylpropyl) amino)-6 (ethoxcarbonylmethylthio) hex-4E-enoate ; 9a) diethyl 2- ( (3-oxo-3- (3-furyl) propyl) amino) nonane-1, 9-dioate; and IOa) diethyl 2- ( (3-oxo-3- (4 benzyloxyphenyl) propyl) amino) nonane 1, 9-dioate; which were converted to: 6b) ethyl 2- ( (3-hydroxy 3-cyclohexylpropyl) amino)-5 (ethoxycarbonylmethylthio) pentanoate: 7b) ethyl 2- ( (3-hydroxy-3-cyclohexylpropyl) amino)-6 (ethoxycarbonylmethylthio) hex-4Z-enoate; 8b) ethyl 2- ( (3-hydroxy-3-cyclohexylpropyl) amino)-6 (ethoxycarbonylmethylthio) hex-4E-enoate ; 9b) diethyl 2- ( (3-hydroxy-3- (3-furyl) propyl) amino) nonane-1, 9dioate; and lOb) diethyl 2- ( (3-hydroxy-3- (4 benzyloxyphenyl) propyl) amino) nonane-1, 9-dioate ; and thence: 6c) 5- (3-carboxymethylthiopropyl)-1- (3-hydroxy-3-cyclohexyl- propyl) hydantoin, 93-96 C ; 7c) 5- (4-carboxymethylthiobut-2Z-enyl)-I- (3-hydroxy-3 cyclohexyl-propyl) hydantain, 117118. 5 , 116117. 5 C 8c) 5- (4-carboxymethylthiobut-2E-enyl)-I- (3-hydroxy-3cyclohexylpropyl) ; 9c) 5- (6-carboxyhexyl)-I- (3-hydroxy-3- (3-furyl) propyl) hydantoin; and IOc) 5- (6-carboxyhexyl)-I- (3-hydroxy-3- (4 benzyloxyphenyl) propyl) hydantoin, 70-71 , 130-130. 5 C.

The starting substances for Examples 6 to 8: 1) diethyl 2-amino-6-thia-octane-1, 8-dioate 2) diethyl 2-amino-7-thia-non-4Z-en-1, 9-dioate, and 3) diethyl 2-amino-7-thia-non-4E-en-1, 9-dioate were obtained from: 1) diethyl 3-chloropropylacetamidomalonate (Coll. Czech. Chem. Comm.

1968, 33, 3823), 2) diethyl 4-chlorobut-2Z-enylacetamidomalonate (cf. Chem. Eng. Data (1970) 205), and 3) diethyl 4-chlorobut-2E-enylacetamidomalonate (Chem. Eng. Data.

(1970) 205), in a manner analogous to that described for the starting substance for Example 5.

EXAMPLE A-Inhibition of Platelet Aggregation Aggregation of platelets in I ml of fresh human platelet rich plasma (PRP) was monitored in a Born aggregometer.

The compound to be tested was added to the PRP at the desired concentration, and the resulting mixture incubated at 37 C for I minute after which platelet aggregation was stimulated by the addition of adenosine diphosphate (ADP) to a concentration of 5 uM.

The anti-aggregatory effect of the compound was assessed by measuring the percentage inhibition of platelet aggregation in the presence of the compound as compared with when it was completely absent.

Each of prostaglandin E, and 5- (4-carboxymethylthio-butyl)-I- (3cyclohexyl-3-hydroxypropyl) hydantoin was tested in this way and the latter was found to be about 20 times more potent than PGE,.

In the following Examples the"Compound"is 5- (4- carboxymethylthiobutyl)-I- (3-cyclohexyl-3-hydroxypropyl) hydantoin.

EXAMPLE B Tablet In one tablet Compound 5.0 mg Lactose B. P. 82.0 mg Starch B. P. 10. 0 mg Povidone B. P. C. 2.0 mg Magnesium Stearate 1. 0 mg Mix together the Compound, lactose and starch. Granulate the powders using a solution of the povidone in Purified Water. Dry the granules, add the Magnesium Stearate and compress to produce tablets, 100 mg per tablet.

EXAMPLE C Capsule In one capsule Compound 10 mg Lactose 79 mg Starch 10 mg Magnesium Stearate 1 mg Mix the powders in a powder blender, fill into hard gelatin capsules, 100 mg per capsule.

EXAMPLE D l, ug/ml Injection Compound I 00, ug Water for Injection to 100 ml Dissolve the Compound in the Water for Injection. Sterilise the solution by filtration through a membrane filter, 0. 22 m pore size, collecting the filtrate in a sterile receiver. Under aseptic conditions, fill sterile glass ampoules with the solution, 1 mut per ampoule. Seal by fusion of the glass.

EXAMPLE E 10, ug/ml Injection Compound mg Ethyl Alcohol 10 ml Propylene Glycol 30 ml Water for Injection to 100 ml Dissolve the Compound in the Ethyl Alcohol, add the Propylene glycol and dilute to volume with Water for Injection.

Sterilise the solution by filtration through a membrane filter, 0.22, um pore size, collecting the filtrate in a sterile vessel. Under aseptic conditions, fill sterile glass vials with the solution, 10 ml per vial. Close with a sterile rubber plug and secure with an aluminium collar.

Claims (32)

1. WHAT WE CLAIM IS :- 1. A compound of formula (I)

   wherein Z is hydrogen or alkyl ; one of Z1 and Z2 is represented by the group -CH,-X-X'-X' wherein X is phenylene,-C=C-, cis or trans-CH=CH-or-CH2-CQ2in which each Q is independently selected from hydrogen and alkyl or the two Q's together form an alkylene radical having four, five or six carbon atoms ; X'is a covalent bond or a straight or branched alkylene chain having I to 6 carbon atoms optionally having one of its methylene groups replaced by oxa (-O-) or thia -S-) provided that at least one carbon atom separates the oxa or thia group from a -C---C-,-CH=CH-or =CO-group ; and X2 is selected from 5-tetrazolyl, carboxyl, carbamoyl, hydroxymethyl and alkoxycarbonyl ; and the other of Z'and Z2 is represented by the group-Y-Y'-YZ-Y' wherein Y is-CR2-CH2-in which each R is independently selected from hydrogen and methyl ; Y'is carbonyl, methylene substituted by hydroxy or methylene substituted by hydroxy and alkyl ; y2 is a covalent bond or straight or branched alkylene having I to 7 carbon atoms optionally substituted on the carbon adjacent Y'by one or two groups each of which is alkyl or a cyclic radical, Y'is hydrogen, hydroxy, alkoxy having I to 7 carbon atoms, a cyclic radical, phenyl, benzyl, phenoxy or benzyloxy, wherein each of phenyl, benzyl, phenoxy and benzyloxy may be substituted in the benzene ring by one or more groups selected from hydroxy, halo, nitro, amino, acylamino, alkenyl, alkoxy, phenyl, benzyloxy and alkyl which may itself be substituted by one or more halo groups ; or y2 and Y3 together form an alkyl group having 1 to 7 carbon atoms of which at least one hydrogen is replaced by fluoro ; or Y is a covalent bond,-CH,-, or-CH,. CH,- and Y1, Y2 and Y3 taken together form a cycloalkyl or bicycloalkyl group substituted by a hydroxy group; or the salts thereof wherein XI is carboxyl or tetrazolyl or Z is hydrogen; Provided that eithet (A) X'is or includes a thia group; or (B) when the value of X'is other than as defined in (A), then (i) at least one of y2 and Y3 includes a cyclic radical other than cycloalkyl having from 3 to 10 carbon atoms, bicycloalkyl having from 4 to 10 carbon atoms, tetrahydrofuranyl or tetrahydropyranyl ; or (ii) Y is a bond,-CH2-or-CH,. CHI-- and Y', Y2 and Y3 are taken together to form a hydroxy-substituted bicycloalkyl group ; or (iii) Y'includes a benzene ring substituted by benzyloxy.
2. 2. A compound as claimed in claim I wherein Y3 is hydrogen, hydroxy, alkoxy having I to 7 carbon atoms, a cyclic radical, phenyl, benzyl, phenoxy or benzyloxy, wherein each of phenyl, benzyl, phenoxy and benzyloxy may be substituted in the benzene ring by one or more groups selected from hydroxy, halogeno, nitro, amino, acylamino, alkenyl, alkoxy, phenyl and alkyl which may itself be substituted by one or more halogeno groups; or Y2 and Y3 together form an alkyl group having I to 7 carbon atoms of which at least one hydrogen is replaced by fluoro ; or Y is a covalent bond,-CH,-, or-CH,. CH,- and Y', Y'and Y3 taken together form a cycloalkyl or bicycloalkyl group substituted by a hydroxyl group; Provided that: (A) X'is or includes a thia group; or (B) when the value of X'is other than as defined in (A), then: (i) at least one of Y2 and includes a cyclic radical other than cycloalkyl of 3 to 10 carbon atoms, bicycloalkyl of 4 to 10 carbon atoms, tetrahydrofuranyl or tetrahydropyranyl ; or (ii) Y is a bond,-CH 2-or-CH,. CH,- and Y', Y'and Y"are taken together to form a hydroxy-substituted bicycloalkyl group.
3. 3. A compound of claim I wherein in formula (I) Z is hydrogen ; one of Z'and Z2 is a group-CH2-X-X1-X2 wherein X is-C=-C-, cis or trans-CH=CH-or-CH,-CH,- ; X'is a covalent bond or a straight or branched alkylene chain having I to 6 carbon atoms optionally having one of its methylene groups replaced by oxa (-0-) or thia (-S-) provided that at least one carbon atom separates the oxa or thia group from a-C=C-,-CH=CH-or-CO-group ; and X2 is selected from carboxyl, carbamoyl, hydroxymethyl and alkoxycarbonyl ; and the other of Z'and Z'is a group-Y-Y-Y'-Y'wherein Y, Y1, Y2 and Y3 are as defined in claim 1.
4. 4. A compound of claim 1 wherein Z is hydrogen; Z'is a group-CH,-X-XI-XI wherein X is cis or trans-CH=CH-or -CH2-CH2-X1 is -CH2.CH2.CH2- ; and X IS carboxyl or alkoxycarbonyl ; and Z'is a group-Y-Y'-Y'-Y'wherein Y is-CH,-CH,- Y'is methylene substituted by hydroxy or methylene substituted by hydroxy and alkyl ; Y2 is a covalent bond or straight or branched alkylene having I to 7 carbon atoms optionally substituted in the carbon adjacent Y'by one or two groups each of which is alkyl or a cyclic radical ; and Y3 is hydrogen, alkoxy of 1 to 7 carbon atoms or a cyclic radical.
5. 5. A compound according to any of claims I to 4, wherein Z is hydrogen; Z'is CH,-X-X'-X'wherein X is-CH2-CHZ ; X'is a covalent bond or a straight or branched alkylene chain having I to 6 carbon atoms; X2 is carboxyl ; and Z2 is-Y-Y'-Yz--Y'wherein Y is-CH,-CH,- ; Y'is methylene substituted by hydroxy; Y2 is a covalent bond or branched alkylene having I to 7 carbon atoms substituted on the carbon adjacent Y'by alkyl or a cyclic radical ; and Y'is as defined in claim 1.
6. 6. A compound according to any of claims I to 5 wherein Z'is-CH2-X- X'-X'wherein X isCH2. CH2- ; X'is an alkylene chain of 3 carbon atoms; X2 is carboxyl ; and Z2 is-Y-Y'-Y-Y'wherein Y to y2 are as defined in claim 5; and Y3 is cycloalkyl having 4 to 7 carbon atom.
7. 7. A compound according to claim 6 wherein cycloalkyl is cyclopentyl or cyclohexyl.
8. 8. A compound selected from: 5- (4-carboxymethylthiobutyl)-I- (3-hydroxy-3- cyclohexylpropyl) hydantoin ; 5- (4-carboxymethylthiobut-2Z-enyl)-I- (3-hydroxy-3cyclohexylpropyl) ; 5- (4-carboxymethylthiobut-2E-enyl)-I- (3-hydroxy-3- cyclohexylpropyl) hydantoin; 5- (6-carboxyhexyl)-I- (3-hydroxy-3- (2-thienyl) propyl) ; 5- (6-carboxyhexyl)-I- (3-hydroxy-3- (2-furyl) propyl) hydantoin ; 5- (6-carboxyhexyl)-I- (3-hydroxy-3- (cyclopent-3- enyl) propyl) hydantoin ; 5- (6-carboxyhexyl)-I- (2a-hydroxynorbornan-3ylmethyl) hydantoin; 5- (3-carboxymethylthiopropyl)-I- (3-hydroxy-3- cyclohexylpropyl) hydantoin ; 5- (6-carboxyhexyl)-I- (3-hydroxy-3- (3-furyl) propyl) hydantoin; 5- (6-carboxyhexyl)-l- (3-hydroxy-3- (4benzyloxyphenyl) propyl) hydantoin; and salts and alkyl esters thereof.
9. 9. The less polar diastereomer of a compound claimed in any preceding claim.
10. 10. A pharmaceutical composition comprising a compound of formula (I) as defined in any preceding claim in association with a pharmaceutically acceptable carrier.
11. 1 I. A composition as claimed in claim 10 wherein the carrier is a liquid.
12. 12. A composition as claimed in claim 10 or I1 in the form of a sterile injectable solution.
13. 13. A composition as claimed in claim 12 comprising from 0.001 to 100, ug of a compound of formula (I) per millilitre.
14. 14. A composition as claimed in claim 12 or 13 in the form of a unit dose comprising from O. 01 to Img of a compound of formula (I).
15. 15. A composition as claimed in claim 10 wherein the carrier is a solid.
16. 16. A composition as claimed in claim 10, or 15 in the form of a unit dose.
17. 17. A composition as claimed in claim 10, 15 or 16 in the form of a tablet, capsule, cachet or suppository.
18. 18. An orally admmistrable unit dose as claimed in claim 16 or 17 comprising from 0.1 to 50mg of a compound of formula (1).
19. 19. A method of preparing a compound according to any of claims I to 9 comprising cyclisation, under acidic conditions or by heating, of a compound of formula (II)

    wherein G is carboxyl or a reactive derivative thereof, and each of Z, Z'and Z2 has the same meaning as in formula (I), as hereinbefore defined.
20. 20. A method of preparing a compound according to any of claims I to 9 comprising cyclisation, under acidic conditions or by heating, of a compound of formula (VII)

    wherein G'is carboxyl or a reactive derivative thereof, and each of Z, Z'and Z2 has the same meaning as in formula (1), as hereinbefore defined.
21. 21. A method of preparing a compound according to any of claims I to 9 comprising reaction of a carbonic acid derivative with a compound of formula (IX)

    wherein each of Z, Z'and Z2 has the same meaning as in formula (1), as hereinbefore defined.
22. 22. A method of preparing a compound according to any of claims l, 2 or 9 wherein Z is alkyl comprising alkylation of a compound of formula (X)

    with a reactive ester derivative of an alcohol of formula J3 OH, wherein J is hydrogen or alkyl, J'is hydrogen or Z', J2 is hydrogen or Zz and J3 is alkyl, Z'or Z2, provided that one of J, J'and J2 is hydrogen and J3 does not have the same value as J, J'or J2 ; in the definition of J', J2 and Jl each oF Z'and z2 having the same meaning as in formula (I), as hereinbefore defined.
23. 23. A method of preparing a compound according to any of claims 1 to 9 comprising reduction of a compound of formula (XI)

    wherein either Z'is =CR-CH,-Y'-Y'-Y'and Z < is-CH.-X-X'-X'or Z is =CH-X-X'-X2 and Z'is-Y-Y'-Y2-Y3 in which each of R, X to X2, Y to Y'and Z is as defined in formula (I), as hereinbefore defined.
24. 24. A compound according to any of claims I to 9 when prepared by a process defined by any of claims 19 to 23.
25. 25. A method of inhibiting the aggregation of platelets which comprises the bringing of said platelets into association with an effective platelet aggregation inhibitory amount of a compound according to any of claims I to 9, other than by administration of said compound to man.
26. 26. A method for the treatment or prophylaxis of thrombosis in a mammal or mammalian tissue, excluding human, which comprises administration of a nontoxic, effective antithrombotic amount of a compound according to any of claims I to 9.
27. 27. A method of lowering blood pressure in a mammal, excluding man, which comprises administration to the mammal of an effective hypotensive, non-toxic amount of a compound according to any of claims I to 9.
28. 28. A method for inducing bronchodilation in a mammal, excluding man, comprising administration to said mammal of a non-toxic, effective bronchodilatory amount of a compound according to any of claims I to 9.
29. 29. A method for inducing vasodilation in a mammal, excluding man, comprising administration to said mammal of a non-toxic, effective vasodilatory amount of a compound according to any of claims I to 9.
30. 30. A method as claimed in any of claims 25 to 29 wherein the compound is administered to a mammal at a daily dose of from l, ug to 20 mg per kilogram of the mammal.
31. 31. A method as claimed in any of claims 25 to 27 or 29 which comprises an intravenous infusion of the compound.
32. 32. The preparation of a compound according to any of claims I to 9 by a method substantially as hereinbefore described with particular reference to Examples I to 10.