Thiazole derivatives having a 5-lipoxygenase-inhibiting activity

Abstract: The invention concerns a thiazole of the formula I, wherein Ar¹ is optionally substituted aryl of up to 10 carbon atoms; A is a direct link to X, or is (1-6C)alkylene, (3-6C)alkenylene, (3-­ 6C)alkynylene or cyclo(3-6C)alkylene; X is oxy, thio, sulphinyl, sulphonyl or imino; Ar² is optionally substituted phenylene, or a 6-membered heterocyclene moiety containing up to three nitrogen atoms; R¹ is hydrogen, (1-6C)alkyl, (2-6C)alkenyl, (2-6C)alkynyl or substituted (1-4C)alkyl; R² is hydrogen, (1-6C)alkyl, (3-6C)alkenyl, (3-6C)alkynyl, substituted (1-4C)alkyl or (2-6C)alkanoyl; Q is optionally substituted thiazolyl; or a pharmaceutically-acceptable salt thereof. The invention also concerns processes for the manufacture of a thiazole of the formula I, or a pharmaceutically-acceptable salt thereof, and pharmaceutical compositions containing said thiazole.

Description: This invention concerns novel heterocyclic compounds and more particularly novel thiazoles which are inhibitors of the enzyme 5-lipoxygenase (hereinafter referred to as 5-LO). The invention also concerns processes for the manufacture of said thiazoles and novel pharmaceutical compositions containing said thiazoles. Also included in the invention is the use of said thiazoles in the treatment of various inflammatory and/or allergic diseases in which the direct or indirect products of 5-LO catalysed oxidation of arachidonic acid are involved, and the production of new medicaments for such use. As stated above the thiazoles described hereinafter are inhibitors of 5-LO, which enzyme is known to be involved in catalysing the oxidation of arachidonic acid to give rise via a cascade process to the physiologically active leukotrienes such as leukotriene B₄ (LTB₄) and the peptido-lipid leukotrienes such as leukotriene C₄ (LTC₄) and leukotriene D₄ (LTD₄) and various metabolites. The biosynthetic relationship and physiological properties of the leukotrienes are summarised by G.W. Taylor and S.R. Clarke in Trends in Pharmacological Sciences , 1986, 7 , 100-103. The leukotrienes and their metabolites have been implicated in the production and development of various inflammatory and allergic diseases such as arthritic diseases, asthma, allergic rhinitis, atopic dermatitis, psoriasis, cardiovascular and cerebrovascular disorders and inflammatory bowel disease. In addition the leukotrienes are mediators of inflammatory diseases by virtue of their ability to modulate lymphocyte and leukocyte function. Other physiologically active metabolites of arachidonic acid, such as the prostaglandins and thromboxanes, arise via the action of the enzyme cyclooxygenase on arachidonic acid. We have now discovered that certain thiazoles are effective as inhibitors of the enzyme 5-LO and thus of leukotriene biosyntheses. Thus, such compounds are of value as therapeutic agents in the treatment of, for example, allergic conditions, asthma, cardiovascular and cerebrovascular disorders, and/or inflammatory and arthritic conditions, mediated alone or in part by one or more leukotrienes. According to the invention there is provided a thiazole of the formula I (set out hereinafter) wherein Ar1 is aryl of up to 10 carbon atoms which may optionally bear one or more substituents selected from halogeno, amino, hydroxy, cyano, formyl, carbamoyl, (1-6C)alkyl, (2-6C)alkenyl, (2-6C)alkynyl, (1-6C)alkoxy, (1-6C)alkylthio, (1-6C)alkylsulphinyl, (1-6C)alkylsulphonyl, (1-6C)alkylamino, di-[(1-4C)alkyl]amino, (1-4C)alkoxycarbonyl, N-[(1-6C)alkyl]carbamoyl, N,N-di-[(1-4C)alkyl]carbamoyl, (2-6C)alkanoyl, (2-6C)alkanoylamino, (1-4C)alkylureido, hydroxy-(1-4C)alkyl and fluoro-(1-4C)alkyl; wherein A is a direct link to X, or is (1-6C)alkylene, (3-6C)alkenylene, (3-6C)alkynylene or cyclo(3-6C)alkylene; wherein X is oxy, thio, sulphinyl, sulphonyl or imino; wherein Ar2 is phenylene which may optionally bear one or two substituents selected from halogeno, hydroxy, amino, nitro, cyano, carbamoyl, (1-6C)alkyl, (1-6C)alkoxy, (3-4C)alkenyloxy, (1-6C)alkylthio, (1-6C)alkylsulphinyl, (1-6C)alkysulphonyl, (1-6C)alkylamino, di-[(1-4C)alkyl]amino, (1-4C)alkoxycarbonyl, N-[(1-6C)alkyl]carbamoyl, N,N-di-[(1-4C)alkyl]carbamoyl, (2-6C)alkanoylamino, fluoro-(1-4C)alkoxy, hydroxy-(2-4C)alkoxy, (1-4C)alkoxy-(2-4C)alkoxy, amino-(2-4C)alkoxy, cyano-(1-4C)alkoxy, carbamoyl-(1-4C)alkoxy, (1-6C)alkylamino-(2-4C)alkoxy, di-[(1-4C)alkyl]amino-(2-4C)alkoxy, (1-4C)alkoxycarbonyl-(1-4C)alkoxy, N-[(1-6C)alkyl]carbamoyl-(1-4C)alkoxy, N,N-[di(1-4C)alkyl]carbamoyl-(1-4C)alkoxy, fluoro-(1-4C)alkyl, hydroxy-(1-4C)alkyl, amino-(1-4C)alkyl, cyano-(1-4C)alkyl, (1-4C)alkoxy-(1-4C)alkyl, (1-4C)alkylamino-(1-4C)alkyl, di-[(1-4C)alkyl]amino-(1-4C)alkyl, (2-6C)alkanoylamino-(1-4C)alkyl, (1-4C)alkoxycarbonyl-(1-4C)alkylamino, carbamoyl-(1-4C)alkylamino, cyano-(1-4C)alkylamino, hydroxy-(2-4C)alkylamino and (1-4C)alkylsulphonamido, or Ar2 is a 6-membered heterocyclene moiety containing up to three nitrogen atoms which may optionally bear one or two substituents selected from halogeno, hydroxy, amino, cyano, (1-6C)alkyl, (1-6C)alkoxy, (1-6C)alkylamino and di-[(1-4C)alkyl]amino; wherein R¹ is hydrogen, (1-6C)alkyl, (2-6C)alkenyl, (2-6C)alkynyl, fluoro-(1-4C)alkyl, cyano-(1-4C)alkyl, hydroxy-(1-4C)alkyl, (1-4C)alkoxy-(1-4C)alkyl and (2-4C)alkanoyloxy-(1-4C)alkyl; wherein R² is hydrogen, (1-6C)alkyl, (3-6C)alkenyl, (3-6C)alkynyl, fluoro-(1-4C)alkyl, (1-4C)alkylthio-(1-4C)alkyl, cyano-(1-4C)alkyl, 1- (1-4C)alkoxycarbonyl-(1-4C)alkyl, carboxy-(1-4C)alkyl, carbamoyl-(1-4C)alkyl or (2-6C)alkanoyl or R² is benzoyl which may optionally bear a substituent selected from halogeno, (1-6C)alkyl or (1-6C)alkoxy; and wherein Q is thiazolyl which may optionally bear one or two substituents selected from halogeno, amino, nitro, cyano, (1-6C)alkyl, (1-6C)alkoxy, (1-6C)alkylamino, di-[(1-4C)alkyl]amino, (1-4C)alkoxycarbonyl, (2-6C)alkanoyl, (2-6C)alkanoylamino, (1-4C)alkoxycarbonylamino, fluoro-(1-4C)alkyl and hydroxy-(1-4C)alkyl; or a pharmaceutically-acceptable salt thereof. The chemical formulae referred to herein by Roman numerals are set out for convenience on a separate sheet hereinafter. In this specification the generic term "alkyl" includes both straight-chain and branched-chain alkyl groups. However references to individual alkyl groups such as "propyl" are specific for the straight-chain version only and references to individual branched-chain alkyl groups such as "isopropyl" are specific for the branched-chain version only. An analogous convention applies to other generic terms. It is to be understood that, insofar as certain of the compounds of formula I defined above may exist in optically active or racemic forms by virtue of one or more substituents containing an asymmetric carbon atom, the invention includes in its definition of active ingredient any such optically active or racemic form which possesses the property of inhibiting 5-LO. The synthesis of optically active forms may be carried out by standard techniques of organic chemistry well known in the art, for example by synthesis from optically active starting materials or by resolution of a racemic form. Similarly, inhibitory properties against 5-LO may be evaluated using the standard laboratory techniques referred to hereinafter. Suitable values for the generic terms referred to above include those set out below. A suitable value for Ar¹ when it is aryl of up to 10 carbon atoms is, for example, phenyl or naphthyl, A suitable value for a halogeno substituent which may be present on Ar¹, Ar², R² or Q is, for example, fluoro, chloro, bromo or iodo. A suitable value for a (1-6C)alkyl substituent which may be present on Ar¹, Ar², R² or Q is, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec -butyl, pentyl or hexyl. A suitable value for a (2-6C)alkenyl substituent on Ar¹, is, for example, vinyl, allyl, 2-butenyl or 3-butenyl. A suitable value for a (2-6C)alkynyl substituent on Ar¹ is, for example, ethynyl, 1-propynyl, 2-propynyl, 1-butynyl or 2-butynyl. A suitable value for a (1-6C)alkoxy substituent which may be present on Ar¹, Ar², R² or Q is, for example, methoxy, ethoxy, propoxy, isopropoxy or butoxy. Suitable values for substituents which may be present on Ar¹ or Ar² include, for example:- for (1-6C)alkythio: methylthio, ethylthio, propylthio, isopropylthio and butylthio; for (1-6C)alkylsulphinyl: methylsulphinyl, ethylsulphinyl, propylsulphinyl, isopropylsulphinyl and butylsulphinyl; for (1-6C)alkylsulphonyl: methylsulphonyl, ethylsulphonyl, propylsulphonyl, isopropylsulphonyl and butylsulphonyl; for N-[(1-6C)alkyl]carbamoyl: N-methylcarbamoyl, N-ethylcarbamoyl and N-propylcarbamoyl; for N,N-di-[(1-4C)alkyl]carbamoyl: N,N-dimethylcarbamoyl and N,N-diethylcarbamoyl. A suitable value for a (2-6C)alkanoyl substituent which may be present on Ar¹ or Q is, for example, acetyl, propionyl or butyryl. Suitable values for substituents which may be present on Ar¹, Ar² or Q include, for example:- for (1-6C)alkylamino: methylamino, ethylamino propylamino and butylamino; for di-[(1-4C)alkyl]amino: dimethylamino, diethylamino and dipropylamino; for (1-4C)alkoxycarbonyl: methoxycarbonyl, ethoxycarbonyl and tert -butoxycarbonyl; for (2-6C)alkanoylamino: acetamido, propionamido, butyramido and hexanamido; for hydroxy-(1-4C)alkyl: hydroxymethyl, 1-hydroxyethyl, 2-hydroxyethyl, 1-hydroxypropyl, 2-hydroxypropyl and 3-hydroxypropyl; for fluoro-(1-4C)alkyl: fluoromethyl, difluoromethyl, trifluoromethyl, 2-fluoroethyl, 2,2,2-trifluoroethyl and pentafluoroethyl. A suitable value for a (1-4C)alkylureido substituent which may be present on Ar¹ is, for example, a 3-(1-4C)alkylureido substituent such as 3-methylureido, 3-ethylureido or 3-propylureido. A suitable value for the number of substituents which may be present on Ar¹ is, for example, one, two or three. A suitable value for A when it is (1-6C)alkylene is, for example, methylene, ethylene, ethylidene, trimethylene, propylidene, tetramethylene or pentamethylene; when it is (3-6C)alkenylene is, for example, 1-propenylene, 2-methylprop-1-enylene, 3-methylprop-1-enylene, 1-butenylene or 2-butenylene; and when it is (3-6C)alkynylene is, for example, 1-propynylene, 3-methylprop-1-ynylene, 1-butynylene or 2-butynylene. A suitable value for A when it is cyclo(3-6C)alkylene is, for example, cyclopropylidene, 1,2-cyclopropylene, cyclopentylidene, 1,2-cyclopentylene, cyclohexylidene or 1,4-cyclohexylene. A suitable value for Ar² when it is phenylene is, for example, 1,3-phenylene or 1,4-phenylene. A suitable value for Ar² when it is a 6-membered heterocyclene moiety containing up to three nitrogen atoms is, for example, pyridylene, pyrimidinylene, pyridazinylene, pyrazinylene or 1,3,5-triazinylene. Conveniently Ar² when it is a 6-membered heterocyclene moiety containing up to three nitrogen atoms is, for example, 2,4-, 2,5-, 3,5- or 2,6-pyridylene, 2,4-, 2,5- or 4,6-pyrimidinylene, 3,5- or 3,6-pyridazinylene or 2,5- or 2,6-pyrazinylene. Suitable values for substituents which may be present on Ar² include, for example:- for (3-4C)alkenyloxy: allyloxy, methylallyloxy, but-2-enyloxy and but-3-enyloxy; for fluoro-(1-4C)alkoxy: fluoromethoxy, difluoromethoxy and trifluoromethoxy; for hydroxy-(2-4C)alkoxy: 2-hydroxyethoxy and 3-hydroxypropoxy; for (1-4C)alkoxy-(2-4C)alkoxy: 2-methoxyethoxy, 3-methoxypropoxy and 2-ethoxyethoxy; for amino-(2-4C)alkoxy: 2-aminoethoxy and 3-aminopropoxy; for cyano-(1-4C)alkoxy: cyanomethoxy,2-cyanoethoxy and 3-cyanopropoxy; for carbamoyl-(1-4C)alkoxy; carbamoylmethoxy, 2-carbamoylethoxy and 3-carbamoylpropoxy; for [(1-6C)alkyl]amino-(2-4C)alkoxy: 2-methylaminoethoxy, 3-methylaminopropoxy and 2-ethylaminoethoxy; for di-[(1-4C)alkyl]amino-(2-4C)alkoxy: 2-dimethylaminoethoxy, 3-dimethylaminopropoxy and 2-diethylaminoethoxy; for (1-4C)alkoxycarbonyl-(1-4C)alkoxy: methoxycarbonylmethoxy, 2-methoxycarbonylethoxy, ethoxycarbonylmethoxy and 2-ethoxycarbonylethoxy; for N-[(1-6C)alkyl]carbamoyl-alkoxy: N-methylcarbamoylmethoxy, 2-(N-methylcarbamoyl)ethoxy, N-ethylcarbamoylmethoxy and 2-(N-ethylcarbamoyl)ethoxy; for N,N-[di-(1-4C)alkyl]carbamoyl-(1-4C)alkoxy: N,N-dimethylcarbamoylmethoxy, 2-(N,N-dimethylcarbamoyl)ethoxy, N,N-diethylcarbamoyl methoxy and 2-(N,N-diethylcarbamoyl)ethoxy; for amino-(1-4C)alkyl: aminomethyl, 2-aminoethyl and 3-aminopropyl; for cyano-(1-4C)alkyl: cyanomethyl, 2-cyanoethyl and 3-cyanopropyl; for (1-4C)alkoxy-(1-4C)alkyl: methoxymethyl, 2-methoxyethyl, 3-methoxypropyl, ethoxymethyl, 2-ethoxyethyl and 3-ethoxypropyl; for (1-4C)alkylamino-(1-4C)alkyl: methylaminomethyl, 2-methylaminoethyl, 3-methylaminopropyl, ethylaminomethyl, 2-ethylaminoethyl and 3-ethylaminopropyl; for di-[(1-4C)alkyl]amino-(1-4C)alkoxy: dimethylaminomethyl, 2-dimethylaminoethyl, 3-dimethylaminopropyl, diethylaminomethyl, 2-diethylaminoethyl and 3-diethylaminopropyl; for (2-6C)alkanoylamino-(1-4C)alkoxy: acetamidomethyl, 2-acetamidoethyl, 3-acetamidopropyl, propionamidomethyl, 2-propionamidoethyl and 3-propionamidopropyl; for (1-4C)alkoxycarbonyl-(1-4C)alkylamino: methoxycarbonylmethylamino, ethoxycarbonylmethylamino, 2-methoxycarbonylethylamino and 2-ethoxycarbonylethylamino; for carbamoyl-(1-4C)alkylamino: carbamoylmethylamino, 2-carbamoylethylamino and 3-carbamoylpropylamino; for cyano-(1-4C)alkylamino: cyanomethylamino, 2-cyanoethylamino and 3-cyanopropylamino; for hydroxy-(2-4C)alkylamino: 2-hydroxyethylamino and 3-hydroxypropylamino; for (1-4C)alkylsulphonamido: methylsulphonamido, ethylsulphonamido and propylsulphonamido. A suitable value for R¹ when it is (1-6C)alkyl is, for example, methyl, ethyl, propyl, butyl, pentyl or hexyl; when it is (2-6C)alkenyl is, for example, vinyl, allyl, 2-butenyl or 3-butenyl; when it is (2-6C)alkynyl is, for example, ethynyl, 1-propynyl, 2-propynyl, 1-butynyl or 2-butynyl; when it is fluoro-(1-4C)alkyl is, for example, fluoromethyl, difluoromethyl, trifluoromethyl, 2-fluoroethyl, 2,2,2-trifluoroethyl or pentafluoroethyl; when it is cyano-(1-4C)alkyl is, for example, cyanomethyl, 2-cyanoethyl or 3-cyanopropyl; when it is hydroxy-(1-4C)alkyl is, for example, hydroxymethyl, 2-hydroxyethyl or 3-hydroxypropyl; when it is (1-4C)alkoxy-(1-4C)alkyl is, for example, methoxymethyl, 2-methoxyethyl, 3-methoxypropyl, ethoxymethyl, 2-ethoxyethyl or 3-ethoxypropyl; and when it is (2-4C)alkanoyloxy-(1-4C)alkyl is, for example, acetoxymethyl, 2-acetoxyethyl, 3-acetoxypropyl, propionyloxymethyl, 2-propionyloxyethyl or 3-propionyloxypropyl. A suitable value for R² when it is (1-6C)alkyl is, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec -butyl, pentyl or hexyl; when it is (3-6C)alkenyl is, for example allyl, 2-butenyl or 3-butenyl; when it is (3-6C)alkynyl is, for example 2-propynyl or 2-butynyl; and when it is (2-4C)alkanoyl is, for example, acetyl, propionyl or butyryl. A suitable value for R² when it is (1-4C)alkoxycarbonyl-(1-4C)alkyl is, for example, methoxycarbonylmethyl, 2-methoxycarbonylethyl, ethoxycarbonylmethyl or 2-ethoxycarbonylethyl; when it is carboxy-(1-4C)alkyl is, for example, carboxymethyl, 2-carboxyethyl or 3-carboxypropyl; when it is carbamoyl-(1-4C)alkyl is, for example, carbamoylmethyl, 2-carbamoylethyl or 3-carbamoylpropyl; when it is cyano-(1-4C)alkyl is, for example, cyanomethyl, 2-cyanoethyl or 3-cyanopropyl; when it is fluoro-(1-4C)alkyl is, for example, trifluoromethyl, 2-fluoroethyl, 2,2-difluoroethyl, 2,2,2-trifluoroethyl or pentafluoroethyl; and when it is (1-4C)alkylthio-(1-4C)alkyl is, for example, methylthiomethyl, ethylthiomethyl, 2-methylthioethyl and 2-ethylthioethyl. A suitable value for Q when it is thiazolyl is 2-, 4- or 5-thiazolyl. A suitable value for (1-4C)alkoxycarbonylamino substituent which may be present on Q is, for example, methoxycarbonylamino, ethoxycarbonylamino and propoxycarbonylamino. A suitable pharmaceutically-acceptable salt of a thiazole of the invention which is sufficiently basic is an acid-addition salt with, for example, an inorganic or organic acid, for example hydrochloric, hydrobromic, sulphuric, phosphoric, trifluoroacetic, citric or maleic acid. In addition a suitable pharmaceutically-acceptable salt of a thiazole of the invention which is sufficiently acidic (for example a thiazole of the invention which contains a carboxy group) is an alkali metal salt, for example a sodium or potassium salt, an alkaline earth metal salt, for example a calcium or magnesium salt, an ammonium salt or a salt with an organic base which affords a physiologically-acceptable cation, for example a salt with methylamine, dimethylamine, trimethylamine, piperidine, morpholine or tris-(2-hydroxyethyl)amine. Particular novel compounds of the invention are, for example, thiazoles of the formula I wherein:- (a) Ar¹ is phenyl, naphth-1-yl or naphth-2-yl which may optionally bear one, two or three substituents selected from fluoro, chloro, bromo, iodo, amino, hydroxy, cyano, formyl, carbamoyl, methyl, methoxy, methylthio, methylsulphinyl, methylsulphonyl, methoxycarbonyl, acetamido, 3-ethylureido, difluoromethyl and trifluoromethyl; and A, X, Ar², R¹, R² and Q have any of the meanings defined hereinbefore; (b) Ar¹ is phenyl or naphth-2-yl which may optionally bear one, two or three substituents selected from fluoro, chloro, bromo, iodo, cyano, methyl, methoxy, methylthio, methylsulphinyl, methylsulphonyl, methoxycarbonyl and trifluoromethyl; and A, X, Ar², R¹, R² and Q have any of the meanings defined hereinbefore; (c) A is a direct link to X, or is methylene, ethylene, trimethylene, 1-propenylene, 2-methylprop-1-enylene or 1-propynylene and Ar¹, X, Ar², R¹, R² and Q have any of the meanings defined hereinbefore; (d) A is methylene, ethylene, trimethylene, 1-propenylene, 2-methylprop-1-enylene or 1-propynylene and Ar¹, X, Ar², R¹, R² and Q have any of the meanings defined hereinbefore; (e) X is oxy, thio, sulphinyl or sulphonyl; and Ar¹, A, Ar², R¹, R² and Q have any of the meanings defined hereinbefore; (f) X is oxy and Ar¹, A, Ar², R¹, R² and Q have any of the meanings defined hereinbefore; (g) Ar² is 1,3-phenylene or 1,4-phenylene which may optionally bear one substituent selected from fluoro, chloro, hydroxy, amino, nitro, cyano, carbamoyl, methyl, ethyl, methoxy, allyloxy, methylthio, methylsulphinyl, methylsulphonyl, methylamino, dimethylamino, methoxycarbonyl, ethoxycarbonyl, tert -butoxycarbonyl, N-methylcarbamoyl, N,N-dimethylcarbamoyl, acetamido, cyanomethoxy, carbamoylmethoxy, methoxycarbonylmethoxy, ethoxycarbonylmethoxy, trifluoromethyl, methoxycarbonylmethylamino, ethoxycarbonylmethylamino, carbamoylmethylamino, cyanomethylamino, 2-hydroxyethylamino and methanesulphonamido; and Ar¹, A, X, R¹, R² and Q have any of the meanings defined hereinbefore; (h) Ar² is 1,3-phenylene or 1,4-phenylene which may optionally bear one substituent selected from chloro, bromo, hydroxy, amino, nitro, methyl, ethyl, methoxy, methylthio, methylsulphinyl, methylsulphonyl, methylamino, dimethylamino, cyanomethoxy, carbamoylmethoxy, N-methylcarbamoylmethoxy and N,N-dimethylcarbamoylmethoxy; and Ar¹, A, X, R¹, R² and Q have any of the meanings defined hereinbefore; (i) Ar² is 2,4-, 2,5-, 3,5- or 2,6-pyridylene or 4,6-pyrimidinylene; and Ar¹, A, X, R¹, R² and Q have any of the meanings defined hereinbefore; (j) Ar² is 2,5-, 3,5- or 2,6-pyridylene or 4,6-pyrimidinylene which may optionally bear one substituent selected from chloro, methyl and methoxy; and Ar¹, A, X, R¹, R² and Q have any of the meanings defined hereinbefore; (k) R¹ is hydrogen, methyl, ethyl, propyl, vinyl, ethyl, 1-propynyl, 2-propynyl, trifluoromethyl, cyanomethyl, hydroxymethyl, methoxymethyl or acetoxymethyl; and Ar¹, A, X, Ar², R² and Q have any of the meanings defined hereinbefore; (l) R¹ is hydrogen, methyl, ethyl, propyl, vinyl, ethynyl, trifluoromethyl, hydroxymethyl, methoxymethyl or acetoxymethyl; and Ar¹, A, X, Ar², R² and Q have any of the meanings defined hereinbefore; (m) R² is hydrogen, methyl, ethyl, propyl, allyl, 2-butenyl, 2-propynyl, 2-butynyl, 2-fluoroethyl, 2,2-difluoroethyl, 2,2,2-trifluoroethyl, methylthiomethyl, cyanomethyl, 2-cyanoethyl, methoxycarbonylmethyl, ethoxycarbonylmethyl, carboxymethyl, carbamoylmethyl or acetyl; and Ar¹, A, X, Ar², R¹ and Q have any of the meanings defined hereinbefore; (n) R² is hydrogen or methyl; and Ar¹, A, X, Ar², R¹ and Q have any of the meanings defined hereinbefore; or (o) Q is 2-, 4- or 5-thiazolyl which may optionally bear one or two substituents selected from chloro, methyl, methoxycarbonyl, acetyl and ethoxycarbonylamino; and Ar¹, A, X, Ar², R¹ and R² have any of the meanings defined hereinbefore; (p) Q is 2- or 4-thiazolyl; and Ar¹, A, X, Ar², R¹ and R² have any of the meanings defined hereinbefore; or a pharmaceutically-acceptable salt thereof. A particular compound of the invention comprises a thiazole of the formula I wherein Ar¹ is phenyl, naphth-1-yl or naphth-2-yl which may optionally bear one, two or three substituents selected from fluoro, chloro, amino, hydroxy, cyano, formyl, carbamoyl, methyl, methoxy, methylthio, methylsulphinyl, methylsulphonyl, methoxycarbonyl, acetamido, difluoromethyl and trifluoromethyl; A is a direct link to X, or is methylene, 1-propenylene, 2-methylprop-1-enylene or 1-propynylene; X is oxy, thio, sulphinyl or sulphonyl; Ar² is 1,3-phenylene or 1,4-phenylene which may optionally bear one substituent selected from fluoro, hydroxy, amino, nitro, cyano, carbamoyl, methyl, methoxy, allyloxy, methylamino, dimethylamino, tert -butoxycarbonyl, acetamido, cyanomethoxy, carbamoylmethoxy, ethoxycarbonylmethoxy, trifluoromethyl, carbamoylmethylamino, cyanomethylamino, 2-hydroxyethylamino and methanesulphonamido, or Ar² is 2,4-, 2,5- or 3,5-pyridylene, or 4,6-pyrimidinylene; R¹ is methyl, ethyl, propyl, vinyl, ethynyl, 2-propynyl, trifluoromethyl, cyanomethyl, hydroxymethyl, methoxymethyl or acetoxymethyl; R² is methyl, ethyl, allyl, 2-propynyl, 2-fluoroethyl, 2,2-difluoroethyl, methylthiomethyl or cyanomethyl; and Q is 2-, 4- or 5-thiazolyl which may optionally bear one substituent selected from chloro, methyl and methoxycarbonyl; or a pharmaceutically-acceptable salt thereof. A preferred compound of the invention comprises a thiazole of the formula I wherein Ar¹ is phenyl, naphth-1-yl or naphth-2-yl which may optionally bear one or two substituents selected from fluoro, chloro, cyano, methyl, methoxy, methylthio, methoxycarbonyl, difluoromethyl and trifluoromethyl; A is a direct link to X, or is methylene, 1-propenylene, 2-methylprop-1-enylene or 1-propynylene; X is oxy, thio, sulphinyl or sulphonyl; Ar² is 1,3-phenylene or 1,4-phenylene which may optionally bear one subtituent selected from fluoro, hydroxy, amino, nitro, methyl, methoxy, methylamino, dimethylamino, cyanomethoxy and trifluoromethyl, or Ar² is 2,5- or 3,5-pyridylene; R¹ is methyl, ethyl, vinyl, 2-propynyl or cyanomethyl; R² is methyl, ethyl, allyl, 2-propynyl or cyanomethyl; and Q is 2- or 4-thiazolyl; or a pharmaceutically-acceptable salt thereof. A further preferred compound of the invention comprises a thiazole of the formula I wherein Ar¹ is phenyl, naphth-2-yl, 3,4-dichlorophenyl, 3-iodophenyl, 3-cyanophenyl, 3,4-dimethoxyphenyl, 3,4,5-trimethoxyphenyl, 4-methylthiophenyl, 4-methylsulphinylphenyl, 3-trifluoromethylphenyl, 6-fluoronaphth-2-yl or 5-cyanonaphth-2-yl; A is methylene, 1-propenylene, 2-methylprop-1-enylene or 1-propynylene; X is oxy; Ar² is 1,3-phenylene, 5-hydroxy-1,3-phenylene, 5-amino-1,3-phenylene, 5-nitro-1,3-phenylene, 4-methyl-1,3-phenylene, 5-methoxy-1,3-phenylene, 5-cyanomethoxy-1,3-phenylene, 5-carbamoylmethoxy-1,3-phenylene, 2,5-pyridylene, 3,5-pyridylene, 2,6-pyridylene or 4,6-pyrimidinylene; R¹ is hydrogen, methyl, ethyl, propyl, vinyl, trifluoromethyl, hydroxymethyl, methoxymethyl or acetoxymethyl; R² is hydrogen or methyl; and Q is 2-thiazolyl or 4-thiazolyl; or a pharmaceutically-acceptable salt thereof. An especially preferred compound of the invention comprises a thiazole of the formula I wherein Ar¹ is phenyl, naphth-1-yl, naphth-2-yl, 2-fluorophenyl, 3-fluorophenyl, 4-fluorophenyl, 3,4-difluorophenyl, 6-fluoronaphth-2-yl, 7-fluoronaphth-2-yl, 2-chlorophenyl, 3-chlorophenyl, 2-tolyl, 6-methylnaphth-2-yl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-methylthiophenyl, 3-methoxycarbonylphenyl, 2-trifluoromethylphenyl, 3-trifluoromethylphenyl or 7-difluoromethylnaphth-2-yl; A is a direct link to X, or is methylene, 1-propenylene or 1-propynylene; X is oxy or thio; Ar² is 1,3-phenylene, 5-fluoro-1,3-phenylene, 5-methoxy-1,3-phenylene, 2-methoxy-1,4-phenylene, 5-cyanomethoxy-1,3-phenylene, 5-trifluoromethyl-1,3-phenylene or 3,5-pyridylene; R¹ is methyl or ethyl; R² is methyl, ethyl, allyl, 2-propynyl or cyanomethyl; and Q is 2-thiazolyl; or a pharmaceutically-acceptable salt thereof. A further especially preferred compound of the invention comprises a thiazole of the formula I wherein Ar¹ is phenyl, naphth-1-yl, 2-fluorophenyl, 3-fluorophenyl, 4-fluorophenyl, 3,4-difluorophenyl, 2-chlorophenyl, 3-chlorophenyl, 2-tolyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 3-methoxycarbonylphenyl, 2-trifluoromethylphenyl or 3-trifluoromethylphenyl; A is 1-propynylene; X is oxy; Ar² is 1,3-phenylene, 5-fluoro-1,3-phenylene, 5-methoxy-1,3-phenylene, 2-methoxy-1,4-phenylene or 5-trifluoromethyl-1,3-phenylene; R¹ is methyl or ethyl; R² is methyl; and Q is 2-thiazolyl; or a pharmaceutically-acceptable salt thereof. A further especially preferred compound of the invention comprises a thiazole of the formula I wherein Ar¹ is phenyl or naphth-2-yl; A is methylene or 1-propynylene; X is oxy; Ar² is 1,3-phenylene, 5-methoxy-1,3-phenylene or 3,5-pyridylene; R¹ is ethyl; R² is methyl and Q is 2-thiazolyl; or a pharmaceutically-acceptable salt thereof. Specific especially preferred compounds of the invention include, for example, the following thiazoles of the formula I, or a pharmaceutically-acceptable salt thereof:- 2-[1-methoxy-1-[3-(naphth-2-ylmethoxy)phenyl]propyl]thiazole; 2-[1-methoxy-1-[5-(naphth-2-ylmethoxy)pyrid-3-yl]propyl]thiazole; 2-[1-methoxy-1-[3-(3-phenylprop-2-ynyloxy)phenyl]propyl]thiazole; 2-[1-methoxy-1-(3-(6-methylnaphth-2-ylmethoxy)phenyl]propyl]thiazole; 2-[1-methoxy-1-(5-methoxy-3-(naphth-2-ylmethoxy)phenyl)propyl]thiazole; 2-[1-methoxy-1-(3-(naphth-2-ylmethoxy)-5-trifluoromethylphenyl)propyl]thiazole; 2-[1-ethoxy-1-(3-(naphth-2-ylmethoxy)-5-trifluoromethylphenyl)propyl]thiazole; 2-[1-allyloxy-1-(5-methoxy-3-(naphth-2-ylmethoxy)phenyl)propyl]thiazole; 2-[1-(5-methoxy-3-(naphth-2-ylmethoxy)phenyl)-1-(propy-2-ynyloxy)propyl]thiazole; 2-[1-methoxy-1-[3-methoxy-(4-(3-phenylprop-2-ynyloxy)phenyl]propyl]thiazole; 2-[1-[3-(3-(3-chlorophenyl)prop-2-ynyloxy)phenyl]-1-methoxypropyl]thiazole; 2-[1-[3-(3-(2-fluorophenyl)prop-2-ynyloxy)phenyl]-1-methoxypropyl]thiazole; 2-[1-[3-(3-(3-fluorophenyl)prop-2-ynyloxy)phenyl]-1-methoxypropyl]thiazole; 2-[1-[3-(3-(4-fluorophenyl)prop-2-ynyloxy)phenyl]-1-methoxypropyl]thiazole; 2-[1-methoxy-1-[3-(3-(naphth-1-yl)prop-2-ynyloxy)phenyl]propyl]thiazole; 2-[1-cyanomethoxy-1-(5-methoxy-3-(naphth-2-ylmethoxy)phenyl)propyl]thiazole; and 2-[1-methoxy-1-(3-(naphth-2-ylthio)phenyl)propyl]thiazole. A compound of the invention comprising a thiazole of the formula I, or a pharmaceutically-acceptable salt thereof, may be prepared by any process known to be applicable to the preparation of structurally-related compounds. Such procedures are provided as a further feature of the invention and are illustrated by the following representative examples in which, unless otherwise stated, Ar¹, A, X, Ar², R¹, R² and Q have any of the meanings defined hereinbefore. (a) The alkylation, in the presence of a suitable base, of a compound of the formula II with a compound of the formula Ar¹-A-Z wherein Z is a displaceable group; provided that, when there is an amino, alkylamino, hydroxy or carboxy group, in Ar¹, Ar², R¹ or Q, any amino, alkylamino or carboxy group is protected by a conventional protecting group and any hydroxy group may be protected by a conventional protecting group or alternatively any hydroxy group need not be protected; whereafter any undesired protecting group in Ar¹, Ar², R¹ or Q is removed by conventional means. A suitable displaceable group Z is, for example, a halogeno, sulphonyloxy or hydroxy group, for example a chloro, bromo, iodo, methanesulphonyloxy, toluene- p -sulphonyloxy or hydroxy group. A suitable reagent for the alkylation reaction when Z is a halogeno or sulphonyloxy group is, for example, a suitable base, for example, an alkali or alkaline earth metal carbonate, hydroxide or hydride, for example sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide, sodium hydride or potassium hyride. The alkylation reaction is preferably performed in a suitable inert solvent or diluent, for example N,N-dimethylformamide, dimethylsulphoxide, acetone, 1,2-dimethoxyethane or tetrahydrofuran, and at a temperature in the range, for example, 10 to 150°C, conveniently at or near ambient temperature. A suitable reagent for the alkylation reaction when Z is a hydroxy group is, for example, the reagent obtained when a compound of the formula Ar¹-A-OH is reacted with a di-(1-4C)alkyl azodicarboxylate in the presence of a triarylphosphine, for example with diethyl azodicarboxylate in the presence of triphenylphosphine. The alkylation reaction is preferably performed in a suitable inert solvent or diluent, for example acetone, 1,2-dimethoxyethane or tetrahydrofuran, and at a temperature in the range, for example, 10 to 80°C, conveniently at or near ambient temperature. A suitable protecting group for an amino or alkylamino group is, for example, an acyl group for example a (1-4C)alkanoyl group (especially acetyl), a (1-4C)alkoxycarbonyl group (especially methoxycarbonyl, ethoxycarbonyl or t -butoxycarbonyl), an arylmethoxycarbonyl group (especially benzyloxycarbonyl) or an aroyl group (especially benzoyl). The deprotection conditions for the above protecting groups necessarily vary with the choice of protecting group. Thus, for example, an acyl group such as an alkanoyl, alkoxycarbonyl or an aroyl group may be removed for example, by hydrolysis with a suitable base such as an alkali metal hydroxide, for example lithium or sodium hydroxide. Alternatively an acyl group such as a t -butoxycarbonyl group may be removed, for example, by treatment with a suitable acid such as hydrochloric, sulphuric or phosphoric acid and an arylmethoxycarbonyl group such as a benzyloxycarbonyl group may be removed, for example, by hydrogenation over a catalyst such as palladium-on-charcoal. A suitable protecting group for a carboxy group is, for example, an esterifying group, for example a (1-4C)alkyl group (especially methyl or ethyl) or an arylmethyl group (especially benzyl). The deprotection conditions for the above protecting groups necessarily vary with the choice of protecting group. Thus, for example, an esterifying group such as an alkyl or arylmethyl group may be removed, for example, by hydrolysis with a suitable base such as an alkali metal hydroxide, for example lithium or sodium hydroxide. Alternatively an esterifying group such as an arylmethyl group may be removed, for example, by hydrogenation over a catalyst such as palladium-on-charcoal. A suitable protecting group for a hydroxy group is, for example, an acyl group, for example a (1-4C)alkanoyl group (especially acetyl), an aroyl group (especially benzoyl) or an arylmethyl group (especially benzyl). The deprotection conditions for the above protecting groups will necessarily vary with the choice of protecting group. Thus, for example, an acyl group such as an alkanoyl or an aroyl group may be removed, for example, by hydrolysis with a suitable base such as an alkali metal hydroxide, for example lithium or sodium hydroxide. Alternatively an arylmethyl group such as a benzyl group may be removed, for example, by hydrogenation over a catalyst such as palladium-on-charcoal. The starting material of the formula II may be obtained, for example, by deprotecting a protected thiazole of the formula III wherein R³ is a protecting group and X, Ar², R¹, R² and Q have the meanings defined hereinbefore. A suitable protecting group R³ is, for example, an arylmethyl group (especially benzyl), a tri-(1-4C)alkylsilyl group (especially trimethylsilyl or t -butyldimethylsilyl), an aryldi-(1-4C)alkylsilyl group (especially dimethylphenylsilyl), a (1-4C)alkyl group (especially methyl), a (1-4C)alkoxymethyl group (especially methoxymethyl) or a tetrahydropyranyl group (especially tetrahydropyran-2-yl). The deprotection conditions for the above protecting groups will necessarily vary with the choice of protecting group. Thus, for example, an arylmethyl group such as a benzyl group may be removed, for example, by hydrogenation over a catalyst such as palladium-on-charcoal. Alternatively a trialkylsilyl or an aryl dialkylsilyl group such as a t -butyldimethylsilyl or a dimethylphenylsilyl group may be removed, for example, by treatment with a suitable acid such as hydrochloric, sulphuric, phosphoric or trifluoroacetic acid or with an alkali metal or ammonium fluoride such as sodium fluoride or, preferably, tetrabutylammonium fluoride. Alternatively an alkyl group may be removed, for example, by treatment with an alkali metal (1-4C)alkylsulphide such as sodium thioethoxide or, for example, by treatment with an alkali metal diarylphosphide such as lithium diphenylphosphide or, for example, by treatment with a boron or aluminium trihalide such as boron tribromide. Alternatively a (1-4C)alkoxymethyl group or tetrahydropyranyl group may be removed, for example, by treatment with a suitable acid such as hydrochloric or trifluoracetic acid. The protecting group R³ may be, for example, a tri-(1-4C)alkylsilyl group which can be removed while the protecting group for any amino, alkylamino, carboxy or hydroxy group in Ar², R¹ or Q is retained. The protected starting material of the formula III may be obtained by standard procedures of organic chemistry. The following process variants are described for the purposes of illustration only and as examples of the many routes available to the man skilled in the art of organic chemistry for the preparation of the starting material of formula III. Further process variants are provided within the Examples provided hereinafter to illustrate further the many options available to the man skilled in the art. Thus, for example, an alcohol of the formula R³-X-Ar²-CH(OH)-Q, wherein R³ is a protecting group as defined hereinbefore, may be obtained by the reaction of an aldehyde of the formula R³-X-Ar²-CHO with an organometallic compound of the formula Q-M, wherein Q has the meaning defined hereinbefore and M is a metallic group, for example lithium, and provided that any amino, alkylamino, carboxy or hydroxy group in Ar² or Q is protected by a conventional protecting group. The reaction may be carried out in, for example, a suitable solvent or diluent such as an ether (for example tetrahydrofuran, t -butylmethylether or diethyl ether) at a temperature in the range, for example, -100 to 50°C (especially -80 to 30°C). The secondary alcohol of the formula R³-X-Ar²-CH(OH)-Q may be oxidised to give a ketone of the formula R³-X-Ar²-CO-Q. A particular suitable oxidising agent is, for example, any agent known in the art for the oxidation of a secondary alcohol to a ketone, for example, manganese dioxide, chromium trioxide pyridine complex, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (hereinafter DDQ), a mixture of dimethylsulphoxide, oxalyl chloride and triethylamine, a mixture of acetic anhydride and dimethylsulphoxide or a mixture of dimethylsulphoxide and a dialkylcarbodiimide, for example N,N′-dicyclohexylcarbodiimide or N-ethyl-N′-(3-dimethylaminopropyl)carbodiimide. A tertiary alcohol of the formula IV, wherein R³ has the meaning defined hereinbefore, may be obtained by the reaction of the ketone R³-X-Ar²-CO-Q with an organometallic compound of the formula R¹-M-Z, wherein M is a metallic group, for example magnesium, and Z is a halogeno group, for example chloro, bromo or iodo, and provided that any amino, alkylamino, carboxy or hydroxy group in Ar², R¹ or Q is protected by a conventional protecting group. The reaction may be carried out in a suitable solvent or diluent such as an ether (for example tetrahydrofuran, t -butyl methyl ether or diethyl ether) at a temperature in the range, for example, -30 to 100°C (especially ambient temperature to 80°C). It will be appreciated that the tertiary alcohol of the formula IV may be obtained from the aldehyde of the formula R³-X-Ar²-CHO by reversing the order of introduction of the groups Q and R¹. Thus the aldehyde of the formula R³-X-Ar²-CHO may be treated initially with the organometallic compound of the formula R¹-M-Z, the product so obtained may be oxidised using a suitable oxidising agent as described above and the resultant ketone may be treated with the organometallic compound Q-M to give the compound of the formula IV, and provided that any amino, alkylamino, carboxy or hydroxy group in Ar², R¹ or Q is protected by a conventional protecting group. The protected thiazole of the formula III, wherein R³ has the meaning defined hereinbefore, may be obtained by the alkylation of the tertiary alcohol of the formula IV with an alkylating agent of the formula R²-Z, wherein Z is a displaceable group as defined hereinbefore other than hydroxy, in the presence of a suitable base as defined hereinbefore, and provided that any amino, alkylamino, carboxy or hydroxy group in Ar², R¹ or Q is protected by a conventional protecting group, Alternatively the tertiary alcohol starting material of the formula IV may be obtained by the reaction of a compound of the formula R³-X-Ar²-Z, wherein R³ and Ar² have the meanings defined hereinbefore and Z is a halogeno group as defined hereinbefore and provided that any amino, alkylamino or hydroxy group in Ar² is protected with a conventional protecting group, with either an organometallic compound of the formula R⁵-M, wherein R⁵ is a (1-6C)alkyl group such as butyl and M is a metallic group, for example lithium, to give an organometallic compound of the formula R³-X-Ar²-M, or with a metal such as magnesium to give an organometallic compound of the formula R³-X-Ar²-M-Z; whereafter either of these organometallic compounds may be reacted with a ketone of the formula R¹-CO-Q, wherein R¹ and Q have the meanings defined hereinbefore, and provided that any amino, alkylamino, carboxy or hydroxy group in R¹ or Q is protected by a conventional protecting group. Alternatively the ketone of the formula R⁴-X-Ar²-CO-Q described hereinbefore may be obtained by the reaction of the nitrile of the formula R³-X-Ar-CN with an organometallic compound of the formula Q-M using the conditions defined hereinbefore for the corresponding reaction of the aldehyde of the formula R³-X-Ar²-CHO. (b) The alkylation, in the presence of a suitable base as defined hereinbefore, of a compound of the formula V with a compound of the formula R²-Z, wherein R² and Z have the meanings defined hereinbefore, provided that, when there is an amino, imino, alkylamino, hydroxy or carboxy group in Ar¹, X, Ar², R¹ or Q, any amino, imino, alkylamino, hydroxy or carboxy group is protected by a conventional protecting group; whereafter any undesired protecting group in Ar¹, X, Ar², R¹ or Q is removed by conventional means. A suitable protecting group for an imino group is, for example, any one of the protecting group defined hereinbefore as a suitable protecting group for an amino or alkylamino group. The following process variants are described for the purposes of illustartion only and as examples of the many routes available to the man skilled in the art of organic chemistry for the preparation of the starting material of formula V. Further purposes variants are provided within the Examples provided hereinafter to illustrate further the many options available to the man skilled in the art. The tertiary alcohol starting material of the formula V may be obtained, for example, by the reaction of an aldehyde of the formula Ar¹-A-X-Ar²-CHO with an organometallic compound of the formula Q-M, having the meaning defined hereinbefore and using the conditions defined hereinbefore, to give a secondary alcohol of the formula Ar¹-A-X-Ar²-CH(OH)-Q and provided that any amino, imino, alkylamino, carboxy or hydroxy group in Ar¹, X, Ar² or Q is protected by a conventional protecting group. The product so obtained may be oxidised using a suitable oxidising agent, as defined hereinbefore, to give a ketone of the formula Ar¹-A-X-Ar²-CO-Q, which in turn may be treated with an organometallic compound of the formula R¹-M-Z, having the meaning defined hereinbefore and using the conditions defined hereinbefore, to give the required tertiary alcohol starting material of the formula V. It will be appreciated that the tertiary alcohol of the formula V may be obtained from the aldehyde of the formula Ar¹-A-X-Ar²-CHO by reversing the order of the introduction of the groups Q and R¹, i.e. by reaction of the aldehyde of the formula Ar¹-A-X-Ar²-CHO with the organometallic compound of the formula R¹-M-Z, oxidation of the secondary alcohol to a ketone of the formula Ar¹-A-X-Ar²-CO-R¹ and reaction of said ketone with the organometallic compound of the formula Q-M, and provided that any amino, imino, alkylamino, carboxy or hydroxy group in Ar, X, Ar², R¹ or Q is protected by a conventional protecting group. Alternatively the ketone intermediate of the formula Ar¹-A-X-Ar²-CO-R¹ may be obtained, for example, by the alkylation, in the presence of a suitable base as defined hereinbefore, of a ketone of the formula H-X-Ar²-CO-R¹ with a compound of the formula Ar¹-A-Z, wherein Z is a displaceable group as defined hereinbefore, and provided that any amino, alkylamino, carboxy or hydroxy group in Ar¹ or Ar² is protected by a conventional protecting group. The aldehyde starting material of the formula Ar¹-A-X-Ar²-CHO may be obtained, for example, by the alkylation, in the presence of a suitable base as defined hereinbefore, of an aldehyde of the formula H-X-Ar²-CHO with a compound of the formula Ar¹-A-Z, wherein Z is a displaceable group, as defined hereinbefore, and provided that any amino, alkylamino, carboxy or hydroxy group in Ar¹ or Ar² is protected by a conventional protecting group. Alternatively the tertiary alcohol starting material of the formula V may be obtained, for example, by the reaction of an ester of the formula Ar¹-A-X-Ar²-CO₂R⁴, wherein R⁴ is a (1-4C)alkyl group such as methyl or ethyl, with an organometallic compound of the formula Q-M, having the meaning defined hereinbefore and using the conditions defined hereinbefore for the corresponding reaction of the aldehyde of the formula R³-X-Ar²-CHO, and provided that any amino, imino, alkylamino, carboxy or hydroxy group in Ar¹, X, Ar² or Q is protected by a conventional protecting group, to give a ketone of the formula Ar¹-A-X-Ar²-CO-Q. The product so obtained may be treated with an organometallic compound of the formula R¹-M-Z, having the meaning defined hereinbefore and using the conditions defined hereinbefore, to give the required tertiary alcohol starting material of the formula V. It will be appreciated that the tertiary alcohol of the formula V may be obtained from the ester of the formula AR¹-A-X-Ar²-CO₂R⁴ by reversing the order of the introduction of the groups Q and R¹, i.e. by reaction of the ester of the formula Ar¹-A-X-Ar²-CO₂-R⁴ with the organometallic compound of the formula R¹-M-Z, to give a ketone of the formula Ar¹-A-X-Ar²-CO-R¹ and reaction of said ketone with the organometallic compound of the formula Q-M, and provided that any amino, imino, alkylamino, carboxy or hydroxy group in Ar¹, X, Ar², R¹ or Q is protected by a conventional protecting group. The ester starting material of the formula Ar¹-A-X-Ar²-CO₂R⁴ may be obtained, for example, by the alkylation, in the presence of a suitable base as defined hereinbefore, of an ester of the formula H-X-Ar²-CO₂R⁴, wherein R⁴ has the meaning defined hereinbefore, with a compound of the formula Ar¹-A-Z, wherein Z is a displaceable group as defined hereinbefore, and provided that any amino, alkylamino, carboxy, or hydroxy group in Ar¹ or Ar² is protected by a conventional protecting group. Alternatively the tertiary alcohol starting material of the formula V may be obtained, for example, by the alkylation, in the presence of a suitable base, of a compound of the formula Ar¹-A-X-H, wherein Ar¹, A and X have the meanings defined hereinbefore, with a compound of the formula Z-Ar²-Z, wherein Z is a displaceable group as defined hereinbefore, and provided that any amino, alkylamino, carboxy or hydroxy group in Ar¹ or Ar² is protected by a conventional protecting group, to give a compound of the formula Ar¹-A-X-Ar²-Z. The product so obtained may be treated with an organometallic compound of the formula R⁵-M, wherein R⁵ is a (1-6C)alkyl group such as butyl and M is a metallic group, for example lithium, to give an organometallic compound of the formula Ar¹-A-X-Ar²-M which may be reacted with a ketone of the formula Q.CO.R¹, provided that any amino, alkylamino or hydroxy group in Q or R¹ is protected by a conventional protecting group, to give the required tertiary alcohol starting material of the formula V. (c) For the production of those compounds of the formula I wherein A is a (3-6C)alkynylene group, the coupling, in the presence of a suitable organometallic catalyst, of a compound of the formula Ar¹-Z wherein Ar¹ has the meaning defined hereinbefore and Z is a halogeno group such as iodo, with an ethynyl compound of the formula VI, wherein A¹ is (1-4C)alkylene and X, Ar², R¹, R² and Q have the meanings defined hereinbefore. A suitable organometallic catalyst is, for example, any agent known in the art for such a coupling reaction. Thus, for example, a suitable reagent is formed when, for example, bis(triphenylphosphine)palladium chloride, and a copper halide, for example cuprous iodide, are mixed. The coupling is generally carried out in a suitable inert solvent or diluent, for example acetonitrile, 1,2-dimethoxyethane or tetrahydrofuran, at a temperature in the range, for example, 10 to 80°C, conveniently at or near 70°C, and in the presence of a suitable base such as, for example, a tri-(1-4C)alkylamine such as triethylamine. The ethynyl compound of the formula VI, used as a starting material, may be obtained, for example, by the alkylation, in the presence of a suitable base, of a compound of the formula II, wherein X, Ar², R¹, R² and Q have the meanings defined hereinbefore, with an alkylating agent of the formula H-C≡C-A¹-Z, wherein A¹ has the meaning defined hereinbefore and Z is a halogeno group, and provided that any amino, alkylamino, carboxy or hydroxy group in Ar², R¹, R² or Q is protected by a convention protecting group. (d) For the production of those compounds of the formula I wherein Ar¹ or Ar² bears an alkylsulphinyl or alkylsulphonyl substituent or X is a sulphinyl or sulphonyl group, the oxidation of a compound of the formula I wherein Ar¹ or Ar² bears an alkylthio substituent or wherein X is a thio group. A suitable oxidising agent is, for example, any agent known in the art for the oxidation of thio to sulphinyl and/or sulphonyl, for example, hydrogen peroxide, a peracid (such as 3-chloroperoxybenzoic or peroxyacetic acid), an alkali metal peroxysulphate (such as potassium peroxymonosulphate), chromium trioxide or gaseous oxygen in the presence of platinum. The oxidation is generally carried out under as mild conditions as possible and with the required stoichiometric amount of oxidising agent in order to reduce the risk of over oxidation and damage to other functional groups. In general the reaction is carried out in a suitable solvent or diluent such as methylene chloride, chloroform, acetone, tetrahydrofuran or t -butyl methyl ether and at a temperature, for example, at or near ambient temperature, that is in the range 15 to 35°C. When a compound wherein X is sulphinyl and/or Ar¹ and/or Ar² bears an alkylsulphinyl substituent a milder oxidising agent may also be used, for example sodium or potassium metaperiodate, conveniently in a polar solvent such as acetic acid or ethanol. It will be appreciated that when a compound of the formula I containing a sulphonyl group is required, it may be obtained by oxidation of the corresponding sulphinyl compound as well as of the corresponding thio compound. (e) For the production of those compounds of the formula I wherein Ar¹, Ar² or Q bears an alkanoylamino or alkanoylaminoalkyl substituent, the acylation of a compound of the formula I wherein Ar¹, Ar² or Q bears an amino or aminoalkyl substituent. A suitable acylating agent is, for example, any agent known in the art for the acylation of amino to acylamino or of aminoalkyl to acylaminoalkyl, for example an acyl halide, for example a (2-6C)alkanoyl chloride or bromide, in the presence of a suitable base, an alkanoic acid anhydride, for example a (2-6C)alkanoic acid anhydride, or an alkanoic acid mixed anhydride, for example the mixed anhydride formed by the reaction of an alkanoic acid and a (1-4C)alkoxycarbonyl halide, for example a (1-4C)alkoxycarbonyl chloride, in the presence of a suitable base. In general the reaction is carried out in a suitable solvent or diluent such as methylene chloride, acetone, tetrahydrofuran or t -butyl methyl ether and at a temperature, for example, at or near ambient temperature, that is in the range 15 to 35°C. A suitable base when it is required is, for example, pyridine, 4-dimethylaminopyridine, triethylamine, ethyldiisopropylamine, N-methylmorpholine, an alkali metal carbonate, for example potassium carbonate, or an alkali metal carboxylate, for example sodium acetate. (f) For the production of those compounds of the formula I wherein R² is alkanoyl or benzoyl optionally bearing a substituent as defined hereinbefore, the acylation of a compound of the formula I wherein R² is hydrogen. For the production of those compounds of the formula I wherein R² is alkanoyl the acylation reaction may be carried out using, for example, a suitable acylating agent as defined hereinbefore. For the production of those compounds of the formula I wherein R² is benzoyl optionally bearing a substituent the acylation may be carried out using, for example, a benzoyl halide, for example a benzoyl chloride or bromide, in the presence of a suitable base as defined hereinbefore. (g) For the production of those compounds of the formula I wherein Ar¹ or Ar² bears an alkenyl substituent, A is alkenylene or R¹ is alkenyl, the reduction of the corresponding compound wherein Ar¹ or Ar² bears an alkynyl substituent, A is alkynylene or R¹ is alkynyl. In general conditions which are standard in the art for the reduction of an alkynyl or alkynylene group are used. Thus, for example, the reduction may be carried out by the hydrogenation of a solution of the alkynyl or alkynylene compound in an inert solvent or diluent in the presence of a suitable metal catalyst. A suitable inert solvent is, for example, an alcohol, for example methanol or ethanol, or an ether, for example tetrahydrofuran or t -butyl methyl ether. A suitable metal catalyst is, for example, palladium or platinum on an inert support, for example charcoal or barium sulphate. Preferably a palladium-on-barium sulphate catalyst is used to substantially prevent over-reduction of the alkynyl or alkynylene group to an alkyl or alkylene group respectively. The reaction is generally carried out at a temperature at or near ambient temperature, that is in the range 15 to 35°C. Alternatively the reduction may be carried out by treating a solution of the alkynyl or alkynylene compound in an inert solvent or diluent with a suitable mixture such as a 1:1 mixture of an organometallic hydride, for example a di-(1-6C)alkylaluminium hydride such as diisobutylaluminium hydride, and an alkyl metal, for example a (1-6C)alkyl lithium such as methyl lithium. A suitable inert solvent or diluent is, for example, tetrahydrofuran, diethyl ether or t -butyl methyl ether and, in general, the reaction is carried out at a temperature, for example, in the range -25°C to ambient temperature (especially -10 to 10°C). (h) For the production of those compounds of the formula I wherein Ar² bears an alkoxy or substituted alkoxy substituent, or an alkylamino or substituted alkylamino substituent, the alkylation of a compound of the formula I wherein Ar² bears a hydroxy or amino substituent. A suitable alkylating agent is, for example, any agent known in the art for the alkylation of hydroxy to alkoxy or substituted alkoxy, or for the alkylation of amino to alkylamino or substituted alkylamino, for example an alkyl or substituted alkyl halide, for example a (1-6C)alkyl chloride, bromide or iodide or a substituted (1-4C)alkyl chloride, bromide or iodide, in the presence of a suitable base. A suitable base for the alkylation reaction is, for example, an alkali or alkaline earth metal carbonate, hydroxide or hydride, for example sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide, sodium hydride or potassium hydride. The alkylation reaction is preferably performed in a suitable inert solvent or diluent, for example N,N-dimethylformamide, dimethylsulphoxide, acetone, 1,2-dimethoxyethane or tetrahydrofuran, and at a temperature in the range, for example, 10 to 150°C, conveniently at or near ambient temperature. (i) For the production of those compounds of the formula I wherein Ar¹, Ar² or Q bears an amino substituent, the reduction of a compound of the formula I wherein Ar¹, Ar² or Q bears a nitro substituent. A suitable reducing agent is, for example, any agent known in the art for the reduction of a nitro group to an amino group. Thus, for example, the reduction may be carried out by the hydrogenation of a solution of the nitro compound in an inert solvent or diluent in the presence of a suitable metal catalyst, for example finely divided platinum metal (obtained by the reduction of platinum oxide in situ ). A suitable inert solvent or diluent is, for example, an alcohol, for example methanol, ethanol or isopropanol, or an ether, for example tetrahydrofuran. A further suitable reducing agent is, for example, an activated metal such as activated iron (produced by washing iron powder with a dilute solution of an acid such as hydrochloric acid). Thus, for example, the reduction may be carried out by heating a mixture of the nitro compound and the activated metal in a suitable solvent or diluent such as a mixture of water and an alcohol, for example, methanol or ethanol, to a temperature in the range, for example, 50 to 150°C, conveniently at or near 70°C. When a pharmaceutically-acceptable salt of a novel compound of the formula I is required, it may be obtained, for example, by reaction of said compound with a suitable acid or base using a conventional procedure. When an optically active form of a compound of the formula I is required, it may be obtained by carrying out one of the aforesaid procedures using an optically active starting material, or by resolution of a racemic form of said compound using a conventional procedure. Many of the intermediates defined herein are novel, for example those of the formulae II, III, IV and V and these are provided as a further feature of the invention. As stated previously, the thiazoles of the formula I are inhibitors of the enzyme 5-LO. The effects of this inhibition may be demonstrated using one or more of the standard procedures set out below:- a) An in vitro spectrophotometric enzyme assay system, which assesses the inhibitory properties of a test compound in a cell free system using 5-LO isolated from guinea pig neutrophils and as described by D.Aharony and R.L. Stein ( J . Biol . Chem ., 1986, 261 (25), 11512-11519). This test provides a measure of the intrinsic inhibitory properties against soluble 5-LO in an extracellular environment. b) An in vitro assay system involving incubating a test compound with heparinised human blood, prior to challenge with the calcium ionophore A23187 and then indirectly measuring the inhibitory effects on 5-LO by assaying the amount of LTB₄ using the specific radioimmunoassay described by Carey and Forder (F. Carey and R.A. Forder, Brit . J . Pharmacol . 1985, 84, 34P) which involves the use of a protein-LTB₄ conjugate produced using the procedure of Young et alia ( Prostaglandins , 1983, 26 (4),605-613). The effects of a test compound on the enzyme cyclooxygenase (which is involved in the alternative metabolic pathway for arachidonic acid and gives rise to prostaglandins, thromboxanes and related metabolites) may be measured at the same time using the specific radioimmunoassay for thromboxane B₂(TxB₂) described by Carey and Forder (see above). This test provides an indication of the effects of a test compound against 5-LO and also cyclooxygenase in the presence of blood cells and proteins. It permits the selectivity of the inhibitory effect on 5-LO or cyclooxygenase to be assessed. c) An ex vivo assay system, which is a variation of test b) above, involving administration of a test compound (usually orally as the suspension produced when a solution of the test compound in dimethylsulphoxide is added to carboxymethylcellulose), blood collection, heparinisation, challenge with A23187 and radioimmunoassay of LTB₄ and TxB₂. This test provides an indication of the bioavailability of a test compound as an inhibitor of 5-LO or cyclooxygenase. d) An in vitro assay system involving the measurement of the inhibitory properties of a test compound against the liberation of LTC₄ and PGE₂ induced by zymosan on mouse resident peritoneal macrophages, using the procedure of Humes (J.L. Humes et alia , Biochem . Pharmacol ., 1983, 32 , 2319-2322) and conventional radioimmunoassay systems to measure LTC₄ and PGE₂. This test provides an indication of inhibitory effects against 5-LO and cyclooxygenase in a non-proteinaceous system. e) An in vivo system involving the measurement of the effects of a test compound in inhibiting the inflammatory response to arachidonic acid in the rabbit skin model developed by D. Aked et alia ( Brit . J . Pharmacol ., 1986, 89 , 431-438). This test provides an in vivo model for 5-LO inhibitors administered topically or orally. f) An in vivo system involving measuring the effects of a test compound administered orally or intravenously on a leukotriene dependent bronchoconstriction induced by an antigen challenge in guinea pigs pre-dosed with an antihistamine (mepyramine), a β-adrenergic blocking agent (propranolol) and a cyclooxygenase inhibitor (indomethacin), using the procedure of W.H. Anderson et alia ( British J Pharmacology , 1983, 78 (1), 67-574). This test provides a further in vivo test for detecting 5-LO inhibitors. Although the pharmacological properties of the compounds of the formula I vary with structural changes as expected, in general compounds of the formula I possess 5-LO inhibitory effects at the following concentrations or doses in one or more of the above tests a)-f):- Test a): IC₅₀ in the range, for example, 0.1-30µM; Test b): IC₅₀ (LTB₄) in the range, for example, 0.01-10µM IC₅₀ (TxB₂) in the range, for example, 15-200µM; Test c): oral ED₅₀ (LTB₄) in the range, for example, 1-200 mg/kg; Test d): IC₅₀ (LTC₄) in the range, for example, 0.001-1µM, IC₅₀ (PGE₂) in the range, for example, 20-1000µM; Test e): inhibition of inflammation in the range, for example, 0.3-100µg intradermally; Test f): ED₅₀ in the range, for example, 0.5-10mg/kg i.v. No overt toxicity or other untoward effects are present in tests c), e) and/or f) when compounds of the formula I are administered at several multiples of their minimum inhibitory dose or concentration. Thus, by way of example, the compound 2-[1-methoxy-1-[3-(naphth-2-ylmethoxy)phenyl]propyl]thiazole has an IC₅₀ of 0.1µM in test a), an IC₅₀ of 0.3µM against LTB₄ and of >100µM against TxB₂ in test b), and an oral ED₅₀ of 10mg/kg versus LTB₄ in test c); and the compound 2-[1-[3-(3-(4-fluorophenyl)prop-2-ynyloxy)phenyl]-1-methoxypropyl]thiazole has an IC₅₀ of 0.04µM against LTB₄ in test b) and an oral ED₅₀ of 10 mg/kg versus LTB₄ in test c). In general those compounds of the formula I which are particularly preferred have an IC₅₀ of <5µM against LTB₄ and of >100µM against TxB₂ in test b), and an oral ED₅₀ of <100 mg/kg against LTB₄ in test c). These compounds are examples of thiazoles of the invention which show selective inhibitory properties for 5-LO as opposed to cyclooxygenase, which selective properties are expected to impart improved therapeutic properties, for example, a reduction in or freedom from the gastrointestinal side-effects frequently associated with cyclooxygenase inhibitors such as indomethacin. According to a further feature of the invention there is provided a pharmaceutical composition which comprises a thiazole of the formula I, or a pharmaceutically-acceptable salt thereof, in association with a pharmaceutically-acceptable diluent or carrier. The composition may be in a form suitable for oral use, for example a tablet, capsule, aqueous or oily solution, suspension or emulsion; for topical use, for example a cream, ointment, gel or aqueous or oily solution or suspension; for nasal use, for example a snuff, nasal spray or nasal drops; for vaginal or rectal use, for example a suppository; for administration by inhalation, for example as a finely divided powder or a liquid aerosol; for sub-lingual or buccal use, for example a tablet or capsule; or for parenteral use (including intravenous, subcutaneous, intramuscular, intravascular or infusion), for example a sterile aqueous or oily solution or suspension. In general the above compositions may be prepared in a conventional manner using conventional excipients. The amount of active ingredient (that is a thiazole of the formula I or a pharmaceutically-acceptable salt thereof) that is combined with one or more excipients to produce a single dosage form will necessarily vary depending upon the host treated and the particular route of administration. For example, a formulation intended for oral administration to humans will generally contain, for example, from 0.5 mg to 2g of active agent compounded with an appropriate and convenient amount of excipients which may vary from about 5 to about 98 percent by weight of the total composition. Dosage units forms will generally contain about 1 mg to about 500 mg of an active ingredient. The invention also includes a thiazole of the formula I, or a pharmaceutically-acceptable salt thereof, for use in a method of treatment of the human or animal body by therapy. The invention also includes a method of treating a disease or medical condition mediated alone or in part by one or more leukotrienes which comprises administering to a warm-blooded animal requiring such treatment an effective amount of an active ingredient as defined above. The invention also provides the use of such an active ingredient in the production of a new medicament for use in a leukotriene mediated disease or medical condition. The size of the dose for therapeutic or prophylactic purposes of a thiazole of the formula I will naturally vary according to the nature and severity of the conditions, the age and sex of the animal or patient and the route of administration, according to well known principles of medicine. As mentioned above, thiazoles of the formula I are useful in treating those allergic and inflammatory conditions which are due alone or in part to the effects of the metabolites of arachidonic acid arising by the linear (5-LO catalysed) pathway and in particular the leukotrienes, the production of which is mediated by 5-LO. As previously mentioned, such conditions include, for example, asthmatic conditions, allergic reactions, allergic rhinitis, allergic shock, psoriasis, atopic dermatitis, cardiovascular and cerebrovasular disorders of an inflammatory nature, arthritic and inflammatory joint disease, and inflammatory bowel diseases. In using a compound of the formula I for therapeutic or prophylactic purposes it will generally be administered so that a daily dose in the range, for example, 0.5mg to 75mg per kg body weight is received, given if required in divided doses. In general lower doses will be administered when a parenteral route is employed. Thus, for example, for intravenous administration, a dose in the range, for example, 0.5mg to 30 mg per kg body weight will generally be used. Similarly, for administration by inhalation, a dose in the range, for example, 0.5 mg to 25 mg per kg body weight will be used. Although the compounds of the formula I are primarily of value as therapeutic agents for use in warm-blooded animals (including man), they are also useful whenever it is required to inhibit the enzyme 5-LO. Thus, they are useful as pharmacological standards for use in the development of new biological tests and in the search for new pharmacological agents. By virtue of their effects on leukotriene production, the compounds of the formula I have certain cytoprotective effects, for example they are useful in reducing or suppressing certain of the adverse gastrointestinal effects of the cyclooxygenase inhibitory non-steroidal anti-inflammatory agents (NSAIA), such as indomethacin, acetylsalicylic acid, ibuprofen, sulindac, tolmetin and piroxicam. Furthermore, co-administration of a 5-LO inhibitor of the formula I with a NSAIA can result in a reduction in the quantity of the latter agent needed to produce a therapeutic effect, thereby reducing the likelihood of adverse side-effects. According to a further feature of the invention there is provided a pharmaceutical composition which comprises a thiazole of the formula I, or a pharmaceutically-acceptable salt thereof as defined hereinbefore, in conjunction or admixture with a cyclooxygenase inhibitory non-steroidal anti-inflammatory agent (such as mentioned above), and a pharmaceutically-acceptable diluent or carrier. The cytoprotective effects of the compounds of the formula I may be demonstrated, for example in a standard laboratory model which assesses protection against indomethacin-induced or ethanol-induced ulceration in the gastrointestinal tract of rats. The compositions of the invention may in addition contain one or more therapeutic or prophylactic agents known to be of value for the disease under treatment. Thus, for example a known platelet aggregation inhibitor, hypolipidemic agent, anti-hypertensive agent, beta-adrenergic blocker or a vasodilator may usefully also be present in a pharmaceutical composition of the invention for use in treating a heart or vascular disease or condition. Similarly, by way of example, an anti-histamine, steroid (such as beclomethasone dipropionate), sodium cromoglycate, phosphodiesterase inhibitor or a beta-adrenergic stimulant may usefully also be present in a pharmaceutical composition of the invention for use in treating a pulmonary disease or condition. The invention will now be illustrated in the following non-limiting Examples in which, unless otherwise stated:- (i) evaporations were carried out by rotary evaporations in vacuo and work-up procedures were carried out after removal of residual solids by filtration; (ii) operations were carried out at room temperature, that is in the range 18-20° and under an atmosphere of an inert gas such as argon; (iii) column chromatography (by the flash procedure) and medium pressure liquid chromatography (MPLC) were performed on Merck Kieselgel silica (Art, 9385) obtained from E. Meck, Darmstadt, W. Germany; (iv) yields are given for illustration only and are not necessarily the maximum attainable; (v) the end-products of the formula I have satisfactory microanalyses and their structures were confirmed by NMR and mass spectral techniques; (vi) intermediates were not generally fully characterised and purity was assessed by thin layer chromatographic, infra-red (IR) or NMR analysis; and (vii) melting points are uncorrected and were determined using a Mettler SP62 automatic melting point apparatus or an oil-bath apparatus; melting points for the end-products of the formula I were determined after recrystallisation from a conventional organic solvent such as ethanol, methanol, acetone, ether or hexane, alone or in admixture. Example 1 A mixture of 2-[1-(3-hydroxyphenyl)-1-methoxypropyl]thiazole (1.5 g), 2-bromomethylnaphthalene (1.48 g), potassium carbonate (0.84 g) and dimethylformamide (15 ml) was stirred at ambient temperature for 18 hours. The mixture was filtered, the filtrate was added to water (100 ml) and the mixture was extracted with ethyl acetate (3 x 50 ml). The organic extracts were combined, washed with a dilute aqueous sodium hydroxide solution and with water, dried (Na₂SO₄) and evaporated. There was thus obtained 2-[1-methoxy-1-[3-(naphth-2-ylmethoxy)phenyl]propyl]thiazole (1.77 g, 75%), m.p. 91-92°C (recrystallised from methanol). The thiazole starting material was obtained as follows:- A slurry of 3-hydroxybenzaldehyde (38 g) in diethyl ether (250 ml) was added over 1 hour to a diethyl ether solution of ethylmagnesium bromide [prepared from bromoethane (75 ml) and magnesium turnings (24 g) under diethyl ether (150 ml)] which had been cooled in an ice-bath to 0°C. The mixture was stirred for 16 hours and allowed to warm to ambient temperature. The mixture was poured into a 5% aqueous hydrochloric acid solution and the resulting mixture was extracted with ethyl acetate (2 x 500 ml). The combined organic extracts were washed with water, with a saturated aqueous sodium chloride solution, dried (Na₂SO₄) and evaporated. The residue was purified by recrystallisation from a mixture of petrol (b.p. 60-80°C) and ethyl acetate. There was thus obtained α-ethyl-3-hydroxybenzyl alcohol (26.7 g). A mixture of the product so obtained (25 g), 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (40 g) and 1,4-dioxan (900 ml) was stirred at ambient temperature for 3 days. The resulting suspension was filtered and the filtrate was evaporated. The residue was purified by recrystallisation from ethyl acetate to give 3-hydroxypropiophenone (18.8 g). Tert -butyldimethylsilyl chloride (22.5 g) was added to a mixture of 3-hydroxypropiophenone (18.7 g), imidazole (21.3 g) and dimethylformamide (100 ml) and the solution was stirred at ambient temperature for 6 hours. The mixture was evaporated and the residue was partitioned between ethyl acetate and water. The organic layer was separated, washed with an aqueous sodium chloride solution, dried (Na₂SO₄) and evaporated. Petrol (b.p. 60-80°C, 250 ml) was added to the residue, the resulting mixture was filtered and the filtrate was evaporated to give 3-( tert )-butyldimethylsilyloxy)propiophenone as a pale yellow oil (31 g) which was used without further purification. A solution of the product so obtained (31 g) in tetrahydrofuran (70 ml) was added dropwise to a cooled (-70°C) solution of thiazol-2-yl-lithium [prepared by adding a solution of n-butyl-lithium (1.6 M in hexane, 80 ml) to a mixture of thiazole (8.8 ml) and tetrahydrofuran (130 ml) which had been cooled to -70°C]. The mixture was stirred at this temperature for 1 hour and at ambient temperature for 2 hours. The mixture was then poured into a cooled, dilute aqueous solution of ammonium acetate and extracted with diethyl ether (3 x 100 ml). The combined organic extracts were washed with water and with a saturated aqueous sodium chloride solution, dired (Na₂SO₄) and evaporated. The residue was purified by column chromatography eluting with toluene/ethyl acetate (5/1 v/v) to give 2-[1-(3- tert -butyldimethylsilyloxyphenyl)-1-hydroxypropyl]thiazole as a pale red oil (31 g). A solution of the product so obtained (31 g) in tetrahydrofuran (150 ml) was added to a slurry of sodium hydride (55% w/w dispersion in oil, 5 g) in tetrahydrofuran (50 ml) and the mixture was stirred at ambient temperature for 1 hour. Methyl iodide (6.6 ml) was added dropwise and the mixture was stirred at ambient temperature for 5 hours. The mixture was poured into a saturated aqueous ammonium chloride solution and extracted with ethyl acetate (3 x 100 ml). The combined extracts were dried (Na₂SO₄) and evaporated and the residue was purified by column chromatography eluting with toluene/ethyl acetate (20/1 v/v) to give 2-[1-(3- tert -butyldimethylsilyloxyphenyl)-1-methoxypropyl]thiazole as a pale yellow oil (20.2 g). A mixture of the product so obtained (20 g), trifluoroacetic acid (112 ml) and water (12 ml) was stirred at ambient temperature for 3 hours. The mixture was evaporated, toluene (100 ml) was added and the mixture was re-evaporated. The residue was partitioned between diethyl ether (150 ml) and dilute aqueous sodium hydroxide solution (150 ml). The aqueous solution was acidified to pH4 by the addition of dilute aqueous hydrochloric acid solution and an ethyl acetate extract (3 x 80 ml) was taken. The combined extracts were washed with water, dried (Na₂SO₄) and evaporated. The residue was recrystallised from a mixture of petrol (b.p. 60-80°C) and ethyl acetate to give 2-[1-(3-hydroxyphenyl)-1-methoxypropyl]thiazole (8 g), m.p. 101-103°C. Example 2 Using a similar procedure to that described in Example 1 except that the appropriate alkylating agent was used in place of 2-bromomethylnaphthalene there were obtained the compounds described in the following table:- Example 3 A solution of 2-[1-hydroxy-1-[3-methoxy-5-(naphth-2-ylmethoxy)phenyl]propyl]thiazole (0.7 g) in tetrahydrofuran (8 ml) was added to slurry of sodium hydride (55% w/w dispersion in oil, 0.105 g) in tetrahydrofuran (2 ml) and the mixture was stirred at ambient temperature for 30 minutes. Methyl iodide (1 ml) was added and the mixture was stirred at ambient temperature for 3 hours. The mixture was poured into a saturated aqueous ammonium chloride solution and extracted with ethyl acetate (3 x 10 ml). The combined extracts were dried (MgSO₄) and evaporated and the residue was purified by column chromatography eluting with methylene chloride to give a gum which crystallised on standing and was recrystallised from methanol. There was thus obtained 2-[1-methoxy-1-[3-methoxy-5-(naphth-2-ylmethoxy)phenyl]propyl]thiazole (0.23 g, 32%), m.p. 88°C. The thiazole starting material was obtained as follows:- Methyl iodide (36 ml) was added to a mixture of methyl 3,5-dihydroxybenzoate (104 g), potassium carbonate (79 g) and dimethylformamide (1200 ml) and the mixture was stirred at ambient temperature for 16 hours. The mixture was partitioned between water (2.5 litre) and petrol (b.p. 60-80°C, 600 ml). The aqueous layer was washed with petrol (b.p. 60-80°C, 600 ml) and then extracted with toluene (2 x 1 litre). The toluene extracts were combined, washed with water (4 x 800 ml), dried (MgSO₄) and evaporated to give methyl 3-hydroxy-5-methoxybenzoate as an oil (33g, 30%). The product so obtained (33 g) was alkylated with 2-bromomethylnaphthalene (36.5 g) using the procedure described in the first paragraph of Example 1. There was thus obtained methyl 3-methoxy-5-(naphth-2-ylmethoxy)benzoate (50.5 g, 91%), m.p. 85-86°C (recrystallised from petrol (b.p. 60-80°C)). A solution of the product so obtained (50 g) in tetrahydrofuran (800 ml) was cooled to -70°C and to this was added a cooled (-70°C) solution of thiazol-2-yl-lithium [prepared by adding 2-bromothiazole (25.6 g) to a mixture of n-butyl-lithium (1.5 M in hexane, 100 ml) and diethyl ether (300 ml) which had been cooled to -70°C]. The mixture was stirred at -20°C for 30 minutes, poured into a saturated aqueous ammonium chloride solution and extracted with diethyl ether (3 x 200 ml). The combined extracts were washed with water, dried (MgSO₄) and evaporated. The residue was purified by crystallisation from acetone to give 3-methoxy-5-(naphth-2-ylmethoxy)phenyl 2-thiazolyl ketone (34 g, 60%), m.p. 105-106°C. A solution of the ketone so obtained (1.2 g) in tetrahydrofuran (20 ml) was added to a diethyl ether solution of ethylmagnesium iodide [prepared from iodoethane (0.6 ml) and magnesium turnings (0.154 g) under diethyl ether (10 ml)] and the mixture was heated to reflux for 15 minutes. The mixture was poured into a saturated aqueous ammonium chloride solution and extracted with ethyl acetate (3 x 15 ml). The combined extracts were washed with water, dried (MgSO₄) and evaporated. The residue was purified by column chromatography eluting with methylene chloride/ethyl acetate (17/3 v/v) to give 2-[1-hydroxy-1-[3-methoxy-5-(naphth-2-ylmethoxy)phenyl]propyl]thiazole (0.72 g, 55%), m.p. 105°C (recrystallised from a mixture of petrol (b.p. 60-80°C) and ethyl acetate). Example 4 Powdered potassium hydroxide (0.155 g) was added to a solution of 2-[1-hydroxy-1-[5-(naphth-2-ylmethoxy)pyrid-3-yl]propyl]thiazole (0.218 g) in dimethylsulphoxide (2 ml) and the mixture was stirred at ambient temperature for 5 minutes. Methyl iodide (0.073 ml) was added and the mixture was stirred at ambient temperature for 30 minutes. The mixture was partitioned between water and methylene chloride (3 x 20 ml). The organic extracts were combined, dried (Na₂SO₄) and evaporated. The residue was purified by column chromatography eluting with increasingly polar mixtures of petrol (b.p. 60-80°C) and ethyl acetate to give 2-[1-methoxy-1-[5-(naphth-2-ylmethoxy)pyrid-3-yl]propyl]thiazole (0.14 g, 62%), m.p. 93-95°C. The thiazole starting material was obtained as follows:- A solution of 2-naphthylmethanol (1.58 g) in dimethylformamide (20 ml) was added to a slurry of sodium hydride (55% w/w dispersion in oil, 0.48 g) in dimethylformamide (2 ml) and the mixture was stirred at ambient temperature for 20 minutes. 3,5-Dibromopyridine (2.37 g) was added and the solution was heated to 120°C for 5 hours and then allowed to stand at ambient temperature overnight. The mixture was poured into water (160 ml) and extracted with ethyl acetate (3 x 50 ml). The combined extracts were washed with water, dried (MgSO₄) and evaporated. The residue was purified by column chromatography eluting with increasingly polar mixtures of petrol (b.p. 60-80°C) and ethyl acetate to give 3-bromo-5-(naphth-2-ylmethoxy)pyridine (1.4 g), m.p. 108-109°C. A solution of the product so obtained (1.26 g) in diethyl ether (30 ml) was cooled to -50°C and n-butyl-lithium (1.5 M in hexane, 3.6 ml) was added dropwise over 10 minutes. The mixture was stirred at -40°C for 10 minutes, cooled to -70°C and a solution of ethyl 2-thiazolyl ketone (0.56 g; Bull. Soc. Chim. France, 1962, 2072) in diethyl ether (15 ml) was added. The mixture was stirred at -70°C for 30 minutes, allowed to warm to ambient temperature, poured into a saturated aqueous ammonium chloride solution and extracted with ethyl acetate (3 x 30 ml). The combined extracts were washed with water, dried (MgSO₄) and evaporated. The residue was purified by column chromatography eluting with increasingly polar mixtures of petrol (b.p. 60-80°C) and ethyl acetate to give 2-[1-hydroxy-1-[5-(naphth-2-ylmethoxy)pyrid-3-yl]propyl]thiazole (0.5 g), m.p. 48-50°C. Example 5 Using a similar procedure to that described in Example 1 except that the appropriate alkyl bromide was used in place of 2-bromomethylnaphthalene and, where appropriate, 2-[1-(3-hydroxyphenyl)-1-methoxyethyl]thiazole was used in place of 2-[1-(3-hydroxyphenyl)-1-methoxypropyl]thiazole there were obtained the compounds described in the following table. The products were purified by column chromatography eluting with increasingly polar mixtures of toluene and ethyl acetate. For those compounds within Example 5 which were oils the following NMR data were obtained (unless otherwise stated the compounds were all dissolved in CDCl₃ and chemical shift values are given on the δ scale):- Compound No. 2 (CD₃SOCD₃) 0.65 (t, 3H), 2.35 (m, 1H), 2.6 (m, 1H), 3.1 (s, 3H), 5.05 (s, 2H), 6.95 (m, 3H), 7.16 (t, 1H), 7.25 (d, 1H), 7.45 (d, 1H), 7.7 (m, 3H), 7.8 (s, 1H). Compound No. 6 0.75 (t, 3H), 2.4 (m, 1H), 2.7 (m, 1H), 3.2 (s, 3H), 5.1 (s, 2H), 7.25 and 7.7 (2d's, 2H, thiazole H's), 6.8-8.1 (m, 8H). Compound No. 8 0.76 (t, 3H), 2.34-2.49 (m, 1H), 2.57-2.72 (m, 1H), 3.20 (s, 3H), 5.09 (s, 2H), 6.8-7.69 (m, 10H). Compound No. 9 0.76 (t, 3H), 2.3-2.51 (m, 1H), 2.58-2.80 (m, 1H), 3.20 (s, 2H), 6.75-7.75 (m, 10H). Compound No. 14 (CD₃SOCD₃) 0.7 (t, 3H), 2.3-2.7 (m, 2H), 3.1 (s, 3H), 4.8 (m, 2H), 7.2 and 7.7 (2d's, 2H, thiazole H's), 6.5-6.6 (2 t's, 1H, olefinic), 6.8-7.0 (d, 1H, olefinic), 6.8-7.7 (m, 8H). Compound No. 16 0.8 (t, 3H), 2.3-2.5 (m, 1H), 2.6-2.8 (m, 1H), 3.2 (s, 3H), 3.8-3.9 (3 s's, 9H), 4.6-4.7 (d, 2H), 6.2-6.4 (2 t's, 1H, olefinic), 6.6-6.7 (d, 1H, olefinic), 6.6-7.3 (m, 6H), 7.2 and 7.7 (2d's, 2H, thiazole H's). Compound No. 19 0.8 (t, 3H), 1.95 (s, 3H), 2.3-2.5 (m, 1H), 2.6-2.8 (m, 1H), 3.2 (s, 3H), 4.55 (s, 2H), 6.6 (s, 1H, olefinic), 6.8-7.4 (m, 10H), 7.7 (d, 1H, thiazole H). Compound No. 20 0.8 (t, 3H), 2.35 (s, 3H), 2.4 (m, 1H), 2.7 (m, 1H), 3.3 (s, 3H), 4.9 (s, 2H), 6.9-7.4 (m, 8H), 7.2 and 7.7 (2 d's, 2H, thiazole H's). Compound No. 21 2.05 (s, 3H), 2.35 (s, 3H), 3.3 (s, 3H), 4.9 (s, 2H), 6.9-7.4 (m, 8H), 7.2 and 7.7 (2 d's, 2H, thiazole H's). Compound Nos. 22, 24, 26, 27 and 29 gave as expected very similar NMR data to those of Compound No. 20 except that the signal at 2.35δ ( p -CH₃) was missing. Compound Nos. 23, 25, 28 and 30 gave as expected very similar NMR data to those of Compound No. 21 except that the signal at 2.35δ ( p -CH₃) was missing. Compound No. 39 0.75 (t, 3H), 2.4 (m, 1H), 2.7 (m, 1H), 3.2 (s, 3H), 5.2 (s, 2H), 6.8 (t, 1H, CHF₂, J =110 Hz, 6.9-7.9 (m, 12H). Information concerning the preparation of appropriate starting materials is provided below:- 2-[1-(3-Hydroxyphenyl)-1-methoxyethyl]thiazole, m.p. 158-160°C, was prepared using the procedure described in Example 1 for the preparation of 2-[1-(3-hydroxyphenyl)-1-methoxypropyl]thiazole except that 3-hydroxyacetophenone was used in place of 3-hydroxypropiophenone. The procedure used to prepare the appropriate ( E )-cinnamyl bromide for use in the preparation of compounds Nos. 12 to 15, 17 and 18 is illustrated below by the description of the preparation of ( E )-3-(3-trifluoromethylphenyl)prop-2-en-1-yl bromide. The other ( E )-cinnamyl bromides were prepared in analogous fashion. Thus:- Ethyl chloroformate (1.4 ml) was added dropwise to a mixture of ( E )-3-(3-trifluoromethylphenyl)propenoic acid (3.2 g), triethylamine (2.1 ml) and tetrahydrofuran (40 ml) which had been cooled to -20°C. The mixture was stirred at -20°C for 30 minutes and filtered. The solid was washed with diethyl ether. The combined filtrate and washings were added dropwise to a solution of sodium borohydride (1.43 g) in water (15 ml) which had been cooled to 3°C. The mixture was stirred at ambient temperature for 3 hours then partitioned between diethyl ether and 2N hydrochloric acid solution. The organic layer was separated, washed with water and with 1N sodium hydroxide solution, dried (MgSO₄) and evaporated. The residue was purified by column chromatography using a 4:1 v/v mixture of toluene and ethyl acetate as eluent. There was thus obtained ( E )-3-(3-trifluoromethylphenyl)prop-2-en-1-ol as a colourless oil (2.53 g). Bromine (0.234 ml) was added dropwise to a mixture of triphenylphosphine (1.18 g) and methylene chloride (15 ml) which had been cooled to 3°C. A cooled (3°C) solution of the prop-2-en-1-ol (0.8 g) described above in methylene chloride (5 ml) was added and the mixture was stirred for 10 minutes and then evaporated. The residue was triturated under diethyl ether (20 ml) and filtered. The filtrate was dried (MgSO₄) and evaporated. There was thus obtained ( E )-3-(3-trifluoromethylphenyl)prop-2-en-1-yl bromide as an oil (1 g). ( E )-3-(3,4,5-Trimethoxyphenyl)prop-2-en-1-ol used in the preparation of the corresponding methanesulphonate for the preparation of Compound No 16 was prepared in analogous fashion. ( E )-2-Methyl-3-phenylprop-2-en-1-yl bromide used as the alkylating agent for Compound No 19 was prepared as follows:- A mixture of α-methylcinnamaldehyde (1.46 g), sodium cyanoborohydride (1.25 g), methyl orange indicator (1 drop) and methanol (20 ml) was acidified to pH3 by the addition of 2N hydrochloric acid solution. The mixture was stirred at ambient temperature for 1.5 hours with sufficient further additions of 2N hydrochloric acid solution to maintain the reaction mixture at pH3. The mixture was evaporated and the residue was partitioned between diethyl ether and 2N hydrochloric acid solution. The organic layer was washed with water, dried (MgSO₄) and evaporated. The residue was purified by column chromatography using a 7:1 v/v mixture of toluene and ethyl acetate as eluent. There was thus obtained ( E )-2-methyl-3-phenylprop-2-en-1-ol as an oil (1.03 g) which was converted to ( E )-2-methyl-3-phenylprop-2-en-1-yl bromide using the procedure described above involving bromine and triphenylphosphine. The procedure used to prepare the appropriate 3-phenylprop-2-ynyl bromide for use in the preparation of Compounds Nos. 20 to 30 is illustrated below by the description of the preparation of 3-(2-chlorophenyl)prop-2-ynyl bromide. The other 3-phenylprop-2-ynyl bromides were prepared in analogous fashion. Thus:- 2-Propynyl alcohol (4.65 ml) was added in one portion to a stirred mixture of 2-chloroiodobenzene (4.76 g), bis(triphenylphosphine)palladium chloride (0.2 g), cuprous iodide (0.2 g), triethylamine (2.78 ml) and acetonitrile (80 ml) and the mixture was heated to 55°C for 1 hour. The mixture was cooled to ambient temperature, poured into water (200 ml) and neutralised by the addition of dilute hydrochloric acid solution. The mixture was extracted with ethyl acetate (2 x 75 ml) and the combined extracts were washed with water (100 ml), with a saturated aqueous sodium chloride solution (100 ml), dried (MgSO₄) and evaporated. The residue was purified by column chromatography using methylene chloride as eluent. There was thus obtained 3-(2-chlorophenyl)prop-2-ynyl alcohol as an oil in 60% yield. A solution of bromine (1.9 g) in methylene chloride (3 ml) was added to a solution of triphenylphosphine (3.46 g) in methylene chloride (40 ml) which had been cooled to 0°C. A solution of a portion (2 g) of the alcohol obtained immediately above in methylene chloride (36 ml) was added and the mixture was stirred for 1 hour and maintained at approximately 3°C. The mixture was evaporated and the residue was purified by column chromatography using methylene chloride as eluent. There was thus obtained 3-(2-chlorophenyl)prop-2-ynyl bromide as an oil in 53% yield. The procedure used to prepare the appropriate 2-bromomethylnaphthalene for use in the preparation of Compounds Nos 33 to 39 is illustrated below by the description of the preparation of 2-bromomethyl-5-cyanonaphthalene. The other 2-bromomethylnaphthalenes were prepared in analogous fashion. Thus:- A mixture of 5-cyano-2-methylnaphthalene (0.75 g), N-bromosuccinimide (0.81 g), 2,2′-azobisisobutyronitrile (0.05 g) and carbon tetrachloride (25 ml) was heated to reflux and irradiated with the light from a 275 watt bulb for 1 hour. The mixture was cooled to ambient temperature and filtered. The filtrate was evaporated and the residue was recrystallised from carbon tetrachloride. There was thus obtained 2-bromoethyl-5-cyanonaphthalene (0.64 g), m.p. 104-106°C. The procedure described immediately above was repeated except that the appropriate 2-methylnaphthalene was used in place of 5-cyano-2-methylnaphthalene and the reaction product was purified by column chromatography using increasingly polar mixtures of petroleum ether (b.p 60-80°C) and toluene as eluent. There was thus obtained the 2-bromomethylnaphthalenes listed below:- 2-bromomethyl-6-fluoronaphthalene a , m.p. 48°C; 2-bromomethyl-7-fluoronaphthalene b , m.p. 62°C; 2-bromomethyl-1-cyanonaphthalene c , oil; 2-bromomethyl-1-trifluoromethylnaphthalene d , oil; 2-bromomethyl-7-difluoromethylnaphthalene e , m.p. 70-71°C; and 2-bromomethyl-3-difluoromethylnaphthalene f , oil. Notes a. 2-Methyl-6-fluoronaphthalene used as a starting material was obtained as follows:- 4-Fluorobenzyl chloride was reacted with acetylacetaldehyde dimethylacetal using the procedure described for the corresponding reaction of 3-methylbenzyl chloride ( Synthesis , 1974, 566). There was thus obtained 4-(4-fluorophenyl)-3-hydroxy-3-methylbutanal dimethylacetal (b.p. 122-130°C at 0.2 mm Hg). A mixture of the material so obtained (15 g), glacial acetic acid (60 ml) and hydrobromic acid (48% w/v. 48 ml) was heated on a steam bath for 1 hour. The mixture was evaporated and the residue was purified by column chromatography using petroleum ether (b.p. 60-80°C) as eluent. There was thus obtained 6-fluoro-2-methylnaphthalene (1 g). b. The procedure described in Note a. above was repeated except that 3-fluorobenzyl chloride was used. There was thus obtained 7-fluoro-2-methylnaphthalene as a white solid. c. 1-Cyano-2-methylnaphthalene used as a starting material is described in J. Amer. Chem. Soc , 1982, 104 , 4644. d. 2-Methyl-1-trifluoromethylnaphthalene used as a starting material was obtained as follows:- A mixture of 1-bromo-2-methylnaphthalene (5 g), sodium trifluoroacetate (12.3 g), cuprous iodide (8.6 g) and N,N-dimethylacetamide (100 ml) was stirred and heated to 160°C for 6 hours. The mixture was cooled, filtered and evaporated. The filtrate was washed with water and with a saturated sodium chloride solution, dried (MgSO₄) and evaporated. The residue was purified by column chromatography using a 49:1 v/v mixture of petroleum ether (b.p. 60-80°C) and toluene as eluent. There was thus obtained 2-methyl-1-trifluoromethylnaphthalene as a colourless oil (2.08 g). e. 7-Difluoromethyl-2-methylnaphthalene used as a starting material was obtained as follows:- A mixture of 2-methyl-7-naphthaldehyde (0.37 g; Bull Soc. Chim. Belg ., 1985, 94 , 205), diethylaminosulphur trifluoride (0.3 ml) and methylene chloride (3 ml) was stirred at ambient temperature for 16 hours. A second portion of the trifluoride (0.6 ml) was added and the reaction was continued for a further 24 hours. The mixture was partitioned between methylene chloride and water. The organic layer was washed with water, dried (MgSO₄) and evaporated. The residue was purified by column chromatography using a 19:1 v/v mixture of petroleum ether (b.p. 60-80°C) and toluene as eluent. There was thus obtained 7-difluoromethyl-2-methylnaphthalene as a solid (0.13 g). f. The procedure described in Note e. above was repeated except that 2-methyl-3-naphthaldehyde was used as a starting material. There was thus obtained 3-difluoromethyl-2-methylnaphthalene as a white solid. Example 6 Using a similar procedure to that described in Example 1 a mixture of 2-[1-(4-hydroxy-3-methoxyphenyl)-1-methoxypropyl]thiazole (0.6 g), 3-(2-chlorophenyl)prop-2-ynyl bromide (0.6 g), potassium carbonate (0.7 g) and dimethylformamide was stirred at ambient temperature for 16 hours. The crude product was purified by column chromatography using methylene chloride as eluent. There was thus obtained 2-[1-[4-(3-(2-chlorophenyl)prop-2-ynyloxy)-3-methoxyphenyl]-1-methoxypropyl]thiazole as an oil (0.3 g). NMR Spectrum (CDCl₃, δ values) 0.8 (t, 3H), 2.3-2.5 (m, 1H), 2.6-2.8 (m, 1H), 3.2 (s, 3H), 3.85 (s, 3H), 5.0 (s, 2H), 7.2-8.2 (m, 9H, aromatics). The thiazole used as a starting material was obtained as follows:- Tert -butyldimethylsilyl chloride (12 g) was added to a mixture of ethyl vanillate (15 g), imidazole (13 g) and tetrahydrofuran (100 ml) and the mixture was stirred at ambient temperature for 48 hours. The mixture was filtered and evaporated to give ethyl 4-( tert -butyldimethylsilyloxy)-3-methoxybenzoate (25.1 g). A solution of the product so obtained in tetrahydrofuran (50 ml) was cooled to -70°C and to this was added a cooled (-70°C) solution of thiazol-2-yl-lithium [prepared by adding 2-bromothiazole (14.1 g) to a mixture of n-butyl-lithium (1.5 M in hexane, 57.3 ml) and diethyl ether (30 ml) which had been cooled to -70°C]. The mixture was stirred for 16 hours and allowed to warm to ambient temperature. The mixture was poured into a saturated aqueous ammonium chloride solution and extracted with ethyl acetate (3 x 100 ml). The combined extracts were washed with water and with a saturated aqueous sodium chloride solution, dried (MgSO₄) and evaporated. The residue was purified by column chromatography using increasingly polar mixtures of methylene chloride and ethyl acetate as eluent. There was thus obtained 4-hydroxy-3-methoxyphenyl 2-thiazolyl ketone (4.5 g) in 24% yield, m.p. 103°C. The product so obtained (4.0 g) was reacted with tert -butyldimethylsilyl chloride using the procedure described immediately above to give 4- tert -butyldimethylsilyloxy-3-methoxyphenyl 2-thiazolyl ketone (6.5 g). A solution of a portion of the ketone so obtained (5.9 g) in tetrahydrofuran (5 ml) was added to a diethyl ether solution of ethylmagnesium iodide [prepared from iodoethane (2.8 ml) and magnesium (0.816 g) under diethyl ether (10 ml)] and the mixture was heated to reflux for 15 minutes. The mixture was poured into a saturated aqueous ammonium chloride solution and extracted with ethyl acetate (3 x 25 ml). The combined extracts were washed with water (2 x 50 ml), with a saturated aqueous sodium chloride solution, dried (MgSO₄) and evaporated. There was thus obtained 2-[1-(4- tert -butyldimethylsilyloxy-3-methoxyphenyl)-1-hydroxypropyl]thiazole (5.8 g). The product so obtained was reacted with methyl iodide using the procedure described in Example 1 except that the product was purified by column chromatography using increasingly polar mixtures of methylene chloride and ethyl acetate as eluent. There was thus obtained 2-[1-(4- tert -butyldimethylsilyloxy-3-methoxyphenyl)-1-methoxypropyl]thiazole (3 g). Tetra-n-butylammonium fluoride (1 M in tetrahydrofuran; 16 ml) was added over 5 minutes to a solution of the product so obtained in tetrahydrofuran (50 ml). The mixture was poured into a saturated aqueous ammonium chloride solution and extracted with ethyl acetate (3 x 70 ml). The combined extracts were washed with water, with a saturated aqueous sodium chloride solution, dried (MgSO₄) and evaporated. There was thus obtained 2-[1-(4-hydroxy-3-methoxyphenyl)-1-methoxypropyl]thiazole (1.3 g), m.p. 127-129°C (recrystallised from a mixture of petroleum ether (b.p. 60-80°C) and methylene chloride). Example 7 The procedure described in Example 6 was repeated except that 3-(4-chlorophenyl)prop-2-ynyl bromide was used in place of the corresponding 2-chlorophenyl isomer. There was thus obtained 2-[1-[4-(3-(4-chlorophenyl)prop-2-ynyloxy)-3-methoxyphenyl]-1-methoxypropyl]thiazole as an oil in 30% yield. NMR Spectrum (CDCl₃, δ values) 0.8 (t, 3H), 2.35-2.48 (m, 1H), 2.6-2.75 (m, 1H), 3.2 (s, 3H), 3.85 (s, 3H), 4.95 (s, 2H), 7.0 (s, 4H), 7.7 (d, 1H), 7.2-7.4 (m, 4H). Example 8 A mixture of 2-[1-(5-hydroxypyrid-3-yl)-1-methoxypropyl]thiazole (0.5 g), sodium hydride (50% w/w dispersion in oil, 0.096 g) and dimethylformamide (20 ml) was stirred at ambient temperature for 30 minutes. The mixture was cooled to -5°C and a solution of 3-phenylprop-2-ynyl bromide (0.39 g) in dimethylformamide (5 ml) was added. The mixture was stirred at -5°C for 1 hour and then partitioned between ethyl acetate and water. The organic layer was dried (MgSO₄) and evaporated. The residue was purified by column chromatography using ethyl acetate as eluent. There was thus obtained 2-[1-methoxy-1-[5-3-phenylprop-2-ynyloxy)pyrid-3-yl]propyl]thiazole as an oil (0.28 g). NMR Spectrum (CDCl₃, δ values) 0.8 (t, 3H), 2.7 (m, 1H), 3.2 (s, 3H), 4.95 (s, 2H), 7.3 (m, 7H), 7.7 (d, 1H), 8.35 (2 d's, 2H). The 2-[1-(5-hydroxypyrid-3-yl)-1-methoxypropyl]thiazole used as a starting material was obtained as follows:- The procedure described in the portion of Example 4 which is concerned with the preparation of starting materials was repeated except that benzyl alcohol was used in place of 2-naphthylmethanol. There was thus obtained 2-[1-(5-benzyloxypyrid-3-yl)-1-hydroxypropyl]thiazole as an oil in 40% yield. NMR Spectrum (CDCl₃, δ values) 5.1 (s, 2H), 7.4 (m, 6H), 8.25 (broad s, 2H). A mixture of the 2-[1-(5-benzyloxypyrid-3-yl)-1-hydroxypropyl]thiazole so obtained (1.63 g), sodium hydride 50% w/w dispersion in oil, 0.24 g) and dimethylformamide (25 ml) was stirred at -8°C for 30 minutes. Methyl iodide (0.71 g) was added and the mixture was stirred at -5°C for 1 hour, poured into a mixture of ice and water and extracted with ethyl acetate (3 x 25 ml). The combined extracts were washed with water, dried (MgSO₄) and evaporated. There was thus obtained 2-[1-(5-benzyloxypyrid-3-yl)-1-methoxypropyl]thiazole as an oil (1.6 g). NMR Spectrum (CDCl₃, δ values) 0.77 (t, 3H), 2.45 (m, 1H), 2.68 (m, 1H), 3.2 (s, 3H), 5.1 (s, 2H), 7.3 (m, 6H), 7.7 (d, 1H), 8.0 (s, 1H), 8.3 (broad d, 2H), A mixture of the product so obtained (1.5 g), 30% palladium-on-charcoal catalyst (1:1 w/w mixture with water, 1.5 g) and ethyl acetate (30 ml) was stirred under an atmosphere of hydrogen for 4 hours. The mixture was filtered. The filtrate was washed with water, dried (MgSO₄) and evaporated. There was thus obtained 2-[1-(5-hydroxypyrid-3-yl)-1-methoxypropyl]thiazole as a white solid (0.78 g), m.p. 133-135°C. Example 9 Using a similar procedure to that described in either Example 3 or Example 4, except that the appropriate 2-[1-hydroxyalkyl]thiazole was used in place of 2-[1-hydroxy-1-[3-methoxy-5-(naphth-2-ylmethoxy)phenyl]propyl]thiazole (Example 3) or 2-(1-hydroxy-1-[5-(naphth-2-ylmethoxy)pyrid-3-yl]propyl]thiazole (Example 4), and the appropriate alkylating agent was, where appropriate, used in place of methyl iodide, there were obtained the compounds described in the following tables. An asterisk (*) is used to identify those compounds which were prepared using a similar procedure to that described in Example 4. Example 10 A solution of 2-[1-methoxy-1-(2-prop-2-ynyloxyphenyl)ethyl]thiazole (0.55 g) in acetonitrile (1 ml) was added in one portion to a stirred mixture of iodobenzene (0.23 ml), triethylamine (0.27 ml), bis(triphenylphosphine)palladium chloride (0.02 g), cuprous iodide (0.02 g) and acetonitrile (2.5 ml), the mixture was stirred at ambient temperature for 15 minutes, and then heated to 60°C for 2.5 hours. The mixture was cooled to ambient temperature, poured into water (50 ml) and neutralized by the addition of dilute hydrochloric acid solution. The mixture was extracted with diethyl ether (2 x 50 ml). The combined extracts were washed with water, dried (MgSO₄) and evaporated. The residue was purified by column chromatography using increasingly polar mixtures of hexane and ethyl acetate as eluent. There was thus obtained 2-[1-methoxy-1-(3-(3-phenylprop-2-ynyloxy)phenyl)ethyl]thiazole (0.33 g, 47%) as an oil. NMR Spectrum (CDCl₃, δ values) 2.05 (s, 3H), 3.3 (s, 3H), 4.9 (s, 2H), 7.3 (d, 1H, thiazole H), 7.7 (d, 1H, thiazole H), 6.9-7.4 (m, 9H). The 2-[1-methoxy-1-(3-prop-2-ynyloxyphenyl)ethyl]thiazole used as a starting material was obtained as follows:- A mixture of 2-[1-(3-hydroxyphenyl)-1-methoxyethyl]thiazoIe (11.8 g), 2-propynyl bromide (80% w/v solution in toluene, 15 ml), potassium carbonate (13 g) and acetone (150 ml) was stirred and heated to reflux for 5 hours. The mixture was cooled to ambient temperature and filtered. The filtrate was evaporated and the residue was partitioned between diethyl ether and water. The organic layer was dried (MgSO₄) and evaporated to give the required starting material as an oil in 62% yield which was used without further purification. Example 11 Using a similar procedure to that described in Example 10 using the appropriate substituted-iodobenzene and 2-[1-methoxy-1-(3-prop-2-ynyloxyphenyl)propyl]thiazole in place of the corresponding 2-ethylthiazole there were obtained the compounds described in the following table:- Example 12 A mixture of 2-[1-(3-(4-methylthiobenzyloxy)phenyl)-1-methoxypropyl]thiazole (Example 5, Compound No. 7; 0.25 g), sodium metaperiodate (0.17 g), methanol (10 ml) and water (1 ml) was stirred at ambient temperature for 16 hours. A second portion of sodium metaperiodate (0.1 g) was added and the mixture was stirred for a further 24 hours. The mixture was partitioned between ethyl acetate and water. The organic layer was washed with a saturated aqueous sodium chloride solution, dried (MgSO₄) and evaporated. The residue was purified by column chromatography using ethyl acetate as eluent. There was thus obtained 2-[1-(3-(4-methylsulphinylbenzyloxy)phenyl)-1-methoxypropyl]thiazole as a gum (0.22 g). NMR Spectrum (CDCl₃, δ values) 0.77 (t, 3H), 2.3-2.52 (m, 1H), 2.31-2.61 (m, 1H), 2.72 (s, 3H), 3.21 (s, 3H), 5.10 (s, 2H), 6.84 (doublet of doublets, 1H), 7.03-7.3 (m, 4H), 7.53-7.72 (m, 5H). Example 13 Titanium trichloride (30% w/v in aqueous hydrochloric acid; 5 ml) was added over 15 minutes to a mixture of ( E )-2-[1-methoxy-1-(3-(3-(4-nitrophenyl)prop-2-enyloxy)phenyl)propyl]thiazole (0.7 g) and tetrahydrofuran (10 ml) and the mixture was stirred at ambient temperature for 2 hours. The mixture was poured onto a mixture of ethyl acetate, concentrated sodium hydroxide solution and ice. The organic phase was separated, washed with water and with a saturated aqueous sodium chloride solution, dried (MgSO₄) and evaporated. The residue was purified by column chromatography using a 4:1 v/v mixture of toluene and ethyl acetate as eluent. There was thus obtained ( E )-2-[1-(3-(3-(4-aminophenyl)prop-2-enyloxy)phenyl)-1-methoxypropyl]-thiazole as a gum (0.38 g). NMR Spectrum (CDCl₃, δ values) 0.8 (t, 3H), 2.3-2.5 (m, 1H), 2.6-2.7 (m, 1H), 3.2 (s, 3H), 3.2-4.0 (broad hump, 2H), 4.6 (m, 2H), 6.1-6.2 (2 t's, 1H, olefinic, 6.6 (d, 1H, olefinic), 6.6-7.3 (m, 9H), 7.7 (d, 1H, thiazole H). The ( E )-2-[1-methoxy-1-(3-(3-(4-nitrophenyl)prop-2-enyloxy)phenyl)propyl]thiazole used as a starting material was obtained by the reaction of (E)-3-(4-nitrophenyl)prop-2-en-1-yl bromide [obtained from (E)-3-(4-nitrophenyl)propenoic acid using the procedure described in Example 5] with 2-[1-(3-hydroxyphenyl)-1-methoxypropyl]thiazole using the procedure described in Example 5. There was thus obtained the required starting material in 63% yield as an oil. NMR Spectrum (CDCl₃, δ values), 0.8 (t, 3 H), 2.3-2.5 (m, 1H), 2.6-2.8 (m, 1H), 3.2 (s, 3H), 4.7 (m, 2H), 6.5-6.6 (d, 1H), 6.7-6.9 (d, 1H), 6.8-7.7 (m, 8H), 8.2 (d, 2H). Example 14 A mixture of 2-[1-methoxy-1-(3-(naphth-2-ylmethoxy)-5-nitrophenyl)propyl]thiazole (Example 9, Compound No. 23; 29.6 g), activated iron (66 g; obtained by stirring a mixture of iron powder and 2 N hydrochloric acid solution for 10 minutes, filtering the mixture and washing and drying the solid), water (340 ml) and methanol (1.16 litres) was stirred vigorously and heated to reflux for 4 hours. A second portion of iron (66 g) and ferrous sulphate (13 g) were added and the mixture was heated to reflux for 16 hours. The mixture was cooled to ambient temperature and filtered. The residue was concentrated and partitioned between ethyl acetate and water. The organic phase was washed with a saturated aqueous sodium chloride solution, dried (MgSO₄) and evaporated. There was thus obtained 2-[1-(5-amino-3-(naphth-2-ylmethoxy)phenyl)-1-methoxypropyl]thiazole (18.9 g, 69%), m.p. 126-127°C (recrystallised from ethyl acetate). Example 15 Acetyl chloride (0.1 ml) was added to a mixture of 2-[1-(5-amino-3-(naphth-2-ylmethoxy)phenyl)-1-methoxypropyl]thiazole (0.48 g), triethylamine (0.2 ml) and methylene chloride (15 ml) which had been cooled to 0°C and the mixture was stirred at this temperature for 15 minutes. The mixture was partitioned between methylene chloride and water. The organic phase was washed with a saturated aqueous sodium chloride solution, dried (MgSO₄) and evaporated. The residue was recrystallised from a mixture of petroleum ether (b.p. 60-80°C) and ethyl acetate. There was thus obtained 2-[1-(5-acetamido-3-(naphth-2-ylmethoxy)phenyl)-1-methoxypropyl]thiazole (0.32 g, 60%), m.p. 144-146°C. Example 16 Methanesulphonyl chloride (0.315 g) was added to a mixture of 2-[1-(5-amino-3-(naphth-2-ylmethoxy)phenyl)-1-methoxypropyl]thiazole (1.01 g), triethylamine (0.505 g) and methylene chloride (5 ml) and the mixture was stirred at ambient temperature for 18 hours. The mixture was partitioned between methylene chloride and water. The organic phase was washed with a saturated aqueous sodium chloride solution, dried (MgSO₄) and evaporated. The residue was purified by column chromatography using a 1:1 v/v mixture of hexane and ethyl acetate as eluent. There was thus obtained 2-[1-methoxy-1-(5-methanesulphonamido-3-(naphth-2-ylmethoxy)phenyl)propyl]thiazole as an oil (0.624 g) in 52% yield. NMR Spectrum (CDCl₃, δ values) 0.78 (t, 3H), 2.31 (m, 1H), 2.58 (m, 1H), 2.84 (s, 3H), 3.13 (s, 3H), 5.10 (s, 2H), 6.60 (s, 1H), 6.75 (t, 1H), 6.83 (t, 1H), 6.86 (t, 1H), 7.27 (d, 1H), 7.40 (m, 3H), 7.61 (d, 1H), 7.75 (m, 4H). Example 17 Ethyl isocyanate (2 ml) was added to a solution of 2-[1-(3-(3-(3-aminophenyl)prop-2-ynyloxy)phenyl)-1-methoxypropyl]thiazole (1.15 g; Example 11, Compound No. 12) in toluene (5 ml) and the mixture was heated to 90°C for 3 hours. The mixture was cooled to ambient temperature and partitioned between ethyl acetate and water. The organic phase was washed with a saturated sodium chloride solution, dried (MgSO₄) and evaporated. The residue was purified by column chromatography using a 1:1 v/v mixture of hexane and ethyl acetate as eluent. There was thus obtained 2-[1-(3-(3-(3-(3-ethylureido)phenyl)prop-2-ynyloxy)phenyl)-1-methoxypropyl]thiazole as an oil (0.4 g) in 29% yield. NMR Spectrum (CDCl₃, δ values) 0.8 (t, 3H), 1.1 (t, 3H), 2.4 (m, 1H), 2.65 (m, 1H), 3.2 (q, 2H), 3.2 (s, 3H), 4.8 (s, 2H), 5.3 (broad, 1H), 6.85-7.4 (m, 9H), 7.65 (d, 1H, thiazole H). Example 18 Acetyl chloride (0.193 g) was added to a mixture of 2-[2-hydroxy-1-methoxy-1-(3-naphth-2-ylmethoxy)phenyl)ethyl]thiazole (0.646 g; Example 9, Compound No. 8), triethylamine (0.166 g) and methylene chloride (10 ml) and the mixture was stirred at ambient temperature for 15 hours. The mixture was evaporated and the residue was purified by column chromatography using a 19:1 v/v mixture of methylene chloride and acetone as eluent. There was thus obtained 2-[2-acetoxy-1-methoxy-1-(3-(naphth-2-ylmethoxy)phenyl)ethyl]thiazole (0.35 g, 49%), m.p. 100-101°C [Example 18, Compound No. 1]. In a similar procedure 2-[1-hydroxy-1-(3-(naphth-2-ylmethoxy)phenyl)ethyl]thiazole (Example 9, Note i.) was reacted with acetic anhydride in the presence of pyridine to give 2-[1-acetoxy-1-(3-naphth-2-ylmethoxy)phenyl)ethyl]thiazole as a gum in 74% yield [Example 18, Compound No. 2]. NMR Spectrum (CDCl₃, δ values) 2.1 (s, 3H), 2.35 (s, 3H), 5.2 (s, 2H), 6.0-7.1 (m, 3H), 7.1-7.3 (m, 2H), 7.5 (m, 3H), 7.7 (d, 1H), 7.8-7.9 (m, 4H). Example 19 A mixture of 2-[1-(3-cinnamyloxyphenyl)-1-methoxypropyl]thiazole (0.25 g; Example 5, Compound No. 11), palladium-on-calcium carbonate catalyst (30 mg) and methanol (5 ml) was stirred at ambient temperature under an atmosphere of hydrogen for 2 hours. The mixture was filtered and the filtrate was evaporated. The residue was purified by column chromatography using increasingly polar mixtures of methylene chloride and diethyl ether as eluent. There was thus obtained 2-[1-methoxy-1-(3-(3-phenylpropoxy)phenyl)propyl]thiazole as an oil (0.22 g) in 87% yield. NMR Spectrum (CDCl₃, δ values) 0.78 (t, 3H), 1.75-3.0 (m, 6H), 3.22 (s,3H), 3.95 (t, 2H), 6.6-7.75 (m, 11H). Example 20 2-[1-(5-Hydroxy-3-(naphth-2-ylmethoxy)phenyl)-1-methoxypropyl]thiazole (Example 9, Compound No. 22) was reacted with ethyl bromoacetate using the conditions described in Example 1. The product was purified by column chromatography using a 10:1 v/v mixture of methylene chloride and ethyl acetate as eluent. There was thus obtained 2-[1-(5-ethoxycarbonylmethoxy-3-(naphth-2-ylmethoxy)phenyl)-1-methoxypropyl]thiazole (Example 20, Compound No. 1) as a gum, in 63% yield. NMR Spectrum (CDCl₃, δ values) 0.75 (t, 3H), 1.3 (t, 3H), 2.4 (m, 1H), 2.6 (m, 1H), 3.25 (s, 3H), 4.2 (q, 2H), 4.55 (s, 2H), 5.2 (s, 2H), 6.5-7.9 (m, 12H). The procedure described above was repeated except that chloroacetonitrile was used in place of ethyl bromoacetate. There was thus obtained 2-[1-(5-cyanomethoxy-3-(naphth-2-ylmethoxy)phenyl-1-methoxypropyl]thiazole (Example 20, Compound No. 2) as a gum, in 58% yield. NMR Spectrum (CDCl₃, δ values) 0.76 (t, 3H), 2.4 (m, 1H), 2.65 (m, 1H), 3.21 (s, 3H), 4.72 (s, 2H), 5.18 (s, 2H), 6.5-7.9 (m, 12H). The procedure described above was repeated except that iodoacetamide was used in place of ethyl bromoacetate. There was thus obtained 2-[1-(5-carbamoylmethoxy-3-(naphth-2-ylmethoxy)phenyl)-1-methoxypropyl]thiazole (Example 20, Compound No. 3) in 16% yield, m.p. 141-143°C. Example 21 2-[1-(3-Hydroxy-4-(naphth-2-ylmethoxy)phenyl)-1-methoxypropyl]thiazole (Example 9, Compound No. 28) was reacted with chloroacetonitrile using the conditions described in Example 1. The product was purified by column chromatography using increasingly polar mixtures of methylene chloride and ethyl acetate as eluent. There was thus obtained 2-[1-(3-cyano-methoxy-4-(naphth-2-ylmethoxy)phenyl)-1-methoxypropyl]thiazole (Example 21, Compound No. 1 as a gum, in 59% yield. NMR Spectrum (CDCl₃, δ values) 0.75 (t, 3H), 2.3-2.45 (m, 1H), 2.6-2.75 (m, 1H), 3.23 (s, 3H), 4.8 (s, 2H), 5.25 (s, 2H), 6.5-7.9 (m, 12H). The procedure described above was repeated except that allyl bromide was used in place of chloroacetonitrile. There was thus obtained 2-[1-(3-allyloxy-4-(naphth-2-ylmethoxy)phenyl-1-methoxypropyl]thiazole (Example 21, Compound No. 2) as a gum, in 84% yield. NMR Spectrum (CDCl₃, δ values) 0.75 (t, 3H), 2.3-2.45 (m, 1H), 2.6-2.75 (m, 1H), 3.2 (s, 3H), 4.6 (d, 2H), 5.2-5.5 (q. 2H), 5.25 (s, 2H), 6.0-6.15 (m, 1H), 6.9-7.9 (m, 12H). The procedure described above was repeated except that ethyl iodide was used in place of chloroacetonitrile. There was thus obtained 2-[1-(3-ethoxy-4-(naphth-2-ylmethoxy)phenyl)-1-methoxypropyl]thiazole (Example 21, Compound No. 3) as a gum in 83% yield. NMR Spectrum (CDCl₃, δ values) 0.75 (t, 3H), 1.45 (t, 3H), 2.3-2.45 (m, 1H), 2.6-2.7, (m, 1H)), 3.2 (s, 3H), 4.05-4.15 (q, 2H), 5.35 (s, 2H), 6.9-7.9 (m, 12H). Example 22 A mixture of 2-[1-(5-amino-3-(naphth-2-ylmethoxy)phenyl)-1-methoxypropyl]thiazole (1.01 g; Example 14), ethyl bromoacetate (0.501 g), potassium carbonate (0.692 g) and N,N-dimethylacetamide (12 ml) was stirred and heated to 80°C for 4 hours. The mixture was cooled to ambient temperature and partitioned between methylene chloride and water. The organic phase was washed with a saturated aqueous sodium chloride solution, dried (MgSO₄) and evaporated. The residue was purified by column chromatography using a 4:1 v/v mixture of hexane and ethyl acetate as eluent. There was thus obtained 2-[1-(5-ethoxycarbonylmethylamino-3-(naphth-2-ylmethoxy)phenyl)-1-methoxypropyl]thiazole (Example 22, Compound No. 1) as a glass (0.877 g), in 72% yield. NMR Spectrum (CDCl₃, δ values) 0.77 (t, 3H), 1.28 (t, 3H), 2.38 (m, 1H), 2.67 (m, 1H), 3.18 (s, 3H), 3.86 (s, 3H), 4.22 (q, 2H), 5.15 (s, 2H), 6.15 (t, 1H), 6.91 (t, 1H), 6.54 (t, 1H), 7.21 (d, 1H), 7.50 (m, 3H), 7.66 (d, 1H), 7.80 (m, 4H). The procedure described above was repeated except that iodoacetamide was used in place of ethyl bromoacetate and the mixture was heated to 80°C for 24 hours. There was thus obtained 2-[1-(5-carbamoylmethylamino-3-(naphth-2-ylmethoxy)phenyl)-1- methoxypropyl]thiazole (Example 22, Compound No. 2) as a glass (0.502 g) in 54% yield. NMR Spectrum (CDCl₃, δ values) 0.76 (t, 3H), 2.37 (m, 1H), 2.63 (m, 1H), 3.18 (s, 3H), 3.73 (s, 2H), 5.14 (s, 2H), 5.52 (broad s, 1H), 6.14 (t, 1H), 6.42 (t, 1H), 6.51 (broad s, 1H), 6.58 (t, 1H), 7.21 (d, 1H), 7.45-7.83 (m, 8H). The procedure described above was repeated except that iodoacetonitrile was used in place of ethyl bromoacetate and the mixture was heated to 80°C for 30 hours. There was thus obtained 2-[1-(5-cyanomethylamino-3-(naphth-2-ylmethoxy)phenyl-1-methoxypropyl]thiazole (Example 22, Compound No. 3) as a gum (0.585 g), in 66% yield. NMR Spectrum (CDCl₃, δ values) 0.77 (t, 3H), 2.39 (m, 1H), 2.67 (m, 1H), 3.21 (s, 3H), 4.04 (s, 2H), 5.16 (s, 2H), 6.24 (t, 1H), 6.5-7.9 (m, 11H). A solution of 2-[1-(5-ethoxycarbonylmethylamino-3-(naphth-2-ylmethoxy)phenyl)-1-methoxypropyl]thiazole (0.877 g; Compound No. 1 immediately above) in diethyl ether (40 ml) was added to a stirred suspension of lithium aluminium hydride (0.3 g) in diethyl ether (20 ml) and the mixture was stirred at ambient temperature for 2.5 hours. Water (30 ml) was carefully added and the mixture was stirred for 30 minutes and filtered. The organic phase was washed with a saturated aqueous sodium chloride solution, dried (MgSO₄) and evaporated. There was thus obtained 2-[1-(5-(2-hydroxyethyl)amino-3-(naphth-2-ylmethoxy)phenyl-1-methoxypropyl]thiazole as a gum (0.545 g), in 68% yield [Example 22, Compound No. 4]. NMR Spectrum (CDCl₃, δ values) 0.78 (t, 3H), 2.37 (m, 1H), 2.64 (m, 1H), 3.19 (s, 3H), 3.26 (t, 2H), 3.79 (t, 2H), 5.15 (s, 2H), 6.22 (t, 1H), 6.43 (t, 1H), 6.52 (t, 1H), 7.20 (d, 1H), 7.5-7.8 (m, 8H). Example 23 Trifluoroacetic anhydride (0.165 ml) was added dropwise to a mixture of 2-[1-(5-amino-3-(naphth-2-ylmethoxy)phenyl-1-methoxypropyl]thiazole (0.43 g; Example 14), triethylamine (0.165 ml) and methylene chloride (20 ml) which had been cooled to 5°C. The mixture was stirred at 5°C for 30 minutes and then partitioned between methylene chloride and water. The organic layer was dried (MgSO₄) and evaporated. A mixture of the trifluoroacetanilide so obtained, methyl iodide (0.27 ml, 4 equivalents) and acetone (5 ml) was heated almost to reflux. Powdered potassium hydroxide (0.24 g, 4 equivalents) was added and the mixture was heated to reflux for 5 minutes. The mixture was evaporated, water (10 ml) and acetone (10 ml) were added to the residue and the mixture was heated to reflux for 10 minutes. The mixture was concentrated and the residue was extracted with ethyl acetate (3 x 50 ml). The combined extracts were washed with water, dried (MgSO₄) and evaporated. The residue was recrystallised from a mixture of petroleum ether (b.p. 60-80°C) and methylene chloride. There was thus obtained 2-[1-methoxy-1-(5-methylamino-3-(naphth-2-ylmethoxy)phenyl)propyl]thiazole (0.183 g, 41%), m.p. 137°C [Example 23, Compound No. 1]. The procedure described above was repeated except that the amount of each of the methyl iodide and potassium hydroxide was increased to 10 equivalents. The product so obtained was purified by column chromatography using a 1:1 v/v mixture of hexane and ethyl acetate as eluent. There was thus obtained 2-[1-(5-dimethylamino-3-(naphth-2-ylmethoxy)phenyl)-1-methoxypropyl]thiazole as a gum, in 31% yield [Example 23, Compound No. 2]. NMR Spectrum (CDCl₃, δ values) 0.78 (t, 3H), 2.40 (m, 1H), 2.67 (m, 1H), 2.91 (s, 6H), 3.20 (s, 3H), 5.17 (s, 2H), 6.30 (m, 1H), 6.53 (m, 2H), 7.19 (d 1H), 7.5-7.9 (m, 8H). Example 24 A mixture of 2-[1-(3-cyano-4-(naphth-2-ylmethoxy)phenyl)-1-methoxypropyl]thiazole (0.65 g; Example 9, Compound No. 29), powdered potassium hydroxide (0.324 g) and tert -butanol (4 ml) was heated to reflux for 2 hours. The mixture was cooled to ambient temperature and partitioned between ethyl acetate and water. The organic layer was washed with a saturated aqueous sodium chloride solution, dried (MgSO₄) and evaporated. The residue was recrystallised from a mixture of petroleum ether (b.p. 60-80°C) and methylene chloride. There was thus obtained 2-[1-(3-carbamoyl-4-(naphth-2-ylmethoxy)phenyl)-1-methoxypropyl]thiazole (0.35 g, 52%), m.p. 177-179°C. Example 25 A mixture of 2-[1-(ethoxycarbonylmethoxy)-1-(5-methoxy-3-(naphth-2-ylmethoxy)phenyl)propyl]thiazole (0.67 g; Example 9, Compound No. 17), sodium hydroxide (0.2 g), water (3 ml) and methanol (15 ml) was stirred at ambient temperature for 18 hours. The mixture was acidified by addition of 5N hydrochloric acid solution and the methanol was evaporated. The residue was partitioned between ethyl acetate and water. The organic phase was dried (MgSO₄) and evaporated. There was thus obtained 2-[1-carboxymethoxy-1-(5-methoxy-3-(naphth-2-ylmethoxy)phenylpropyl]thiazole (0.56 g, 90%), m.p. 160-161°C. Example 26 A mixture of 2-[1-methoxycarbonylmethoxy-1-(5-methoxy-3-(naphth-2-ylmethoxy)phenyl)propyl]thiazole (0.66 g; obtained in 56% yield using the procedure described for the preparation of Compound No. 17 of Example 9 except that methyl iodoacetate was used as the alkylating agent) and a saturated solution of ammonia in methanol (50 ml) was stirred at ambient temperature for 3 hours. The mixture was evaporated and the residue was purified by column chromatography using increasingly polar mixtures of petroleum ether (b.p. 60-80°C) and ethyl acetate as eluent. There was thus obtained 2-[1-carbamoylmethoxy-1-(5-methoxy-3-(naphth-2-ylmethoxy)phenyl)propyl]thiazole (0.5 g, 78%), m.p. 60-62°C. Example 27 Trifluoroacetic anhydride (0.153 ml) was added to a mixture of 2-[1-carbamoylmethoxy-1-(5-methoxy-3-(naphth-2-ylmethoxy)phenyl)-propyl]thiazole (0.462 g, Example 26), pyridine (0.16 ml) and dimethoxyethane (2 ml) which had been cooled to 0°C. The mixture was stirred at ambient temperature for 3 hours and partitioned between diethyl ether and water. The organic layer was washed with 2N hydrochloric acid solution and with water, dried (MgSO₄) and evaporated. The residue was purified by column chromatography using increasingly polar mixtures of petroleum ether (b.p. 60-80°C) and ethyl acetate as eluent. There was thus obtained 2-[1-cyanomethoxy-1-(5-methoxy-3-(naphth-2-ylmethoxy)phenyl)propyl]thiazole as a gum (0.33 g) in 75% yield. NMR Spectrum (CDCl₃, δ values) 0.82 (t, 3H), 2.4 (m, 2H), 3.78 (s, 3H), 4.13 (s, 2H), 5.18 (s, 2H), 6.52 (t, 1H), 6.61 (t, 1H), 6.67 (t, 1H), 7.3 (d, 1H), 7.46-7.9 (m, 8H). Example 28 Trifluoroacetic acid (0.2 ml) was added to amixture of 2-[1-(3- tert -butoxycarbonyl-4-(naphth-2-ylmethoxy)phenyl)-1-methoxypropyl]thiazole (1.9 g; Example 9, Compound No. 30) and methylene chloride (50 ml) and the mixture was stirred at ambient temperature for 2 hours. The mixture was evaporated and the residue was partitioned between ethyl acetate and water. The organic layer was washed with a saturated aqueous sodium hydrogen carbonate solution and with water, dried (MgSO₄) and evaporated. The residue was purified by column chromatography using increasingly polar mixtures of methylene chloride and ethyl acetate as eluent. There was thus obtained 2-[1-(3-carboxy-4-(naphth-2-ylmethoxy)phenyl)-1-methoxypropyl]thiazole (0.7 g). A mixture of the product so obtained and oxalyl chloride (5 ml) was stirred at ambient temperature for 30 minutes. The mixture was evaporated and a solution of the residue in methylene chloride (10 ml) was added to a saturated solution of dimethylamine in methanol (5 ml). The mixture was stirred at ambient temperature for 30 minutes. The mixture was partitioned between ethyl acetate and water. The organic layer was washed with 2N hydrochloric acid solution and with water, dried (MgSO₄) and evaporated. The residue was purified by column chromatography using increasingly polar mixtures of petroleum ether (b.p. 60-80°C) and ethyl acetate as eluent. There was thus obtained 2-[1-(3-dimethylcarbamoyl-4-(naphth-2-ylmethoxy)phenyl)-1-methoxypropyl)thiazole as an oil, in 20% yield (Example 28, Compound No. 1). NMR Spectrum (CDCl₃, δ values) 0.75 (t, 3H), 2.4 (m, 1H), 2.65 (m, 1H), 2.8 (s, 3H), 3.1 (s, 3H), 3.2 (s, 3H), 5.25 (s, 2H), 6.95 (d, 1H), 7.25 (d, 1H), 7.4-7.55 (m, 5H), 7.7 (d, 1H), 7.8-7.9 (m, 4H). In a similar procedure for the conversion of an appropriate acid to an amide, a mixture of 2-[1-(3-(3-(3-carboxyphenyl)prop-2-ynyloxy)phenyl)-1-methoxypropyl]thiazole (0.4 g) and oxalyl chloride (4 ml) was stirred at ambient temperature for 30 minutes. The mixture was evaporated and the residue was dissolved in tetrahydrofuran (2 ml). A concentrated aqueous ammonium hydroxide solution (4 ml) was added and the mixture was stirred at ambient temperature for 10 minutes. The mixture was partitioned between diethyl ether and water. The organic layer was washed with water, dried (MgSO₄) and evaporated. The residue was purified by column chromatography using a 3:1 v/v mixture of ethyl acetate and hexane. There was thus obtained 2-[1-(3-(3-(3-carbamoylphenyl)prop-2-ynyloxy)phenyl)-1-methoxypropyl]thiazole as an oil in 70% yield (Example 28, Compound No. 2). NMR Spectrum (CDCl₃, δ values) 0.76 (t, 3H), 2.45 (m, 1H), 2.65 (m, 1H), 3.2 (s, 3H), 4.9 (s, 2H), 5.8-6.5 (broad lump, 2H), 7.2 (d, 1H), 6.9-8.2 (m, 9H). The 2-[1-(3-(3-(3-carboxyphenyl)prop-2-ynyloxy)phenyl)-1-methoxypropyl]thiazole used as a starting material was obtained by basic hydrolysis of the corresponding 3-methoxycarbonyl-substituted compound (Example 11, Compound No. 9) using the procedure described in Example 25. There was thus obtained the required starting material as an oil in 93% yield. Example 29 Using a similar procedure to that described in Example 1 except that the reaction duration was 30 minutes ( E )-cinnamyl bromide was reacted with 2-[1-(3,5-dihydroxyphenyl)-1-methoxypropyl]thiazole. The product was purified by column chromatography using a 5:1 v/v mixture of petroleum ether (b.p. 60-80°C) and ethyl acetate as eluent. There was thus obtained 2-[1-(3-( E )-cinnamyloxy-5-hydroxyphenyl)-1-methoxypropyl]thiazole (0.06 g, 11%), m.p. 137-138°C. The 2-[1-(3,5-dihydroxyphenyl)-1-methoxypropyl]thiazole used as a starting material was obtained as follows:- Water (1 ml) was added to a mixture of 2-[1-(5- tert -butoxydimethylsilyloxy-3-(naphth-2-ylmethoxy)phenyl)-1-methoxypropyl]thiazole (1.25 g; Example 9, Note t.) and trifluoroacetic acid (6 ml) which had been cooled to 0°C. The mixture was stirred and allowed to warm to ambient temperature. The mixture was partitioned between ethyl acetate and a saturated aqueous ammonium chloride solution. The organic phase was washed with a saturated aqueous sodium bicarbonate solution, with a saturated aqueous sodium chloride solution dried (MgSO₄) and evaporated. The residue was purified by column chromatography using increasingly polar mixtures of petroleum ether (b.p. 60-80°C) and ethyl acetate as eluent. There was thus obtained the required starting material as an oil (0.5 g) in 78% yield. Example 30 Using a similar procedure to that described in Example 3, except that the appropriate 2-, 4- or 5-substituted thiazole was used in place of 2-[1-hydroxy-1-[3-methoxy-5-(naphth-2-ylmethoxy)phenyl]propyl]thiazole, there were obtained the compounds described in the following table. Example 31 A solution of 2-[1-methoxy-1-(3-(naphth-2-ylmethoxy)phenyl)propyl]thiazole (1.56 g) in diethyl ether (32 ml) was added dropwise to a mixture of n-butyl-lithium (1.6 M in hexane, 4 ml) and diethyl ether (32 ml) which had been cooled to -78°C and the mixture was stirred at this temperature for 1 hour. A solution of p -toluenesulphonyl chloride (1.22 g) in diethyl ether (6 ml) was added dropwise. The mixture was stirred at -78°C for 30 minutes and at ambient temperature for 2 hours. The mixture was partitioned between diethyl ether and water. The organic layer was dried (MgSO₄) and evaporated. The residue was purified by column chromatography using a 4:1 v/v mixture of methylene chloride and petroleum ether (b.p. 60-80°C) as eluent. There was thus obtained 5-chloro-2-[1-methoxy-1-(3-(naphth-2-ylmethoxy)phenyl)propyl]thiazole (0.5 g, 30%), m.p. 82-85°C [Example 31, Compound No. 1]. The procedure described above was repeated except that acetyl chloride was used in place of p -toluenesulphonyl chloride. There was thus obtained 5-acetyl-2-[1-methoxy-1-(3-(naphth-2-ylmethoxy)phenyl)propyl]thiazole in 20% yield, m.p. 93-94°C [Example 31, Compound No. 2]. Example 32 A mixture of 2-[1-methoxy-1-(3-naphth-2-ylmethoxy)phenyl)-propyl]thiazole-5-carboxylic acid (0.5 g) and thionyl chloride (5 ml) was heated to reflux for 30 minutes. The mixture was evaporated. A mixture of the residue so obtained, methanol (5 ml), triethylamine (1 ml) and methylene chloride (10 ml) was stirred at 0°C for 1 hour. The mixture was partitioned between methylene chloride and 2N hydrochloric acid. The organic layer was separated, washed with water, dried (MgSO₄) and evaporated. There was thus obtained methyl 2-[1-methoxy-1-(3-(naphth-2-ylmethoxy)phenyl)propyl]thiazole-5-carboxylate in 76% yield, m.p. 92-95°C. The 2-[1-methoxy-1-(3-(naphth-2-ylmethoxy)phenyl)propyl]-thiazole-5-carboxylic acid used as a starting material was obtained as follows:- A solution of 2-[1-methoxy-1-(3-(naphth-2-ylmethoxy)phenyl)propyl]thiazole (1.56 g) in diethyl ether (32 ml) was added dropwise to a mixture of n-butyl-lithium (1.6 M in hexane, 4 ml) and diethyl ether (32 ml) which had been cooled to -78°C and the mixture was stirred at this temperature for 1 hour. An excess of solid carbon dioxide was added and the mixture was allowed to warm to ambient temperature and stirred for 1.5 hours. The mixture was partitioned between diethyl ether and 0.1 N sodium hydroxide solution. The aqueous phase was acidified by the additon of 2N hydrochloric acid solution and extracted with a 1:1 v/v mixture of diethyl ether and ethyl acetate. The organic phase was dried (MgSO₄) and evaporated. There was thus obtained the required starting material (1.15 g, 66%), m.p. 161-163°C. Example 33 Diphenylphosphoryl azide (0.587 ml) was added to a stirred suspension of 2-[1-methoxy-1-(3-(naphth-2-ylmethoxy)phenyl)propyl]-thiazole-2-carboxylic acid (1.08 g) in dimethylformamide (3 ml) which had been cooled to 0°C. The mixture was stirred at 0°C for 30 minutes and at ambient temperature for 2.5 hours. Ethanol (2 ml) was added and the mixture was heated to reflux for 2 hours. The mixture was partitioned between diethyl ether and water. The organic phase was washed with water and with a saturated aqueous sodium chloride solution, dried (MgSO₄) and evaporated. The residue was purified by column chromatography using increasingly polar mixtures of methylene chloride and diethyl ether as eluent. There was thus obtained 5-ethoxycarbonylamino-2-[1-methoxy-1-(3-(naphth-2-ylmethoxy)phenyl)propyl]thiazole (0.3 g, 25%), m.p. 68-70°C (crystallised under water). Example 34 The procedure described in Example 3 was repeated except that 2-[1-hydroxy-1-(3-(naphth-2-ylthio)phenyl)propyl]thiazole was used in place of 2-[1-hydroxy-1-[3-methoxy-5-(naphth-2-ylmethoxy)phenyl]propyl]thiazole. The reaction product was purified by column chromatography using increasingly polar mixtures of hexane and ethyl acetate as eluent. There was thus obtained 2-[1-methoxy-1-(3-(naphth-2-ylthio)phenyl)propyl]thiazole as an oil, in 86% yield. NMR Spectrum (CDCl₃, δ values) 0.75 (t, 3H), 2.4 (m, 1H), 2.65 (m, 1H), 3.2 (s, 3H), 7.2-7.58 (m, 8H), 7.65-7.85 (m, 5H). The 2-[1-hydroxy-1-(3-(naphth-2-ylthio)phenyl)propyl]thiazole used as a starting material was obtained as follows:- A mixture of 2-naphthalenethiol (12.94 g), 3-bromopropiophenone (17.35 g), cuprous oxide (5.83 g), sodium hydroxide (3.24 g) and dimethylformamide (130 ml) was heated to reflux for 18 hours. The mixture was concentrated and the residue was partitioned between diethyl ether and water. The organic phase was dried (MgSO₄) and evaporated. The residue was dissolved in a mixture of ethyl acetate and hexane and treated with charcoal. The solution was filtered and evaporated. The residue was recrystallised from a mixture of methanol and water to give 3-(naphth-2-ylthio)propiophenone (5.23 g, 22%), m.p. 90-91°C. A solution in tetrahydrofuran (5 ml) of a portion (1 g) of the product so obtained was treated with thiazol-2-yl-lithium [prpeared from thiazole (0.29 g) and n-butyl-lithium (1.6 M in hexane, 2.2 ml)] using the conditions described in the 4th paragraph of the portion of Example 1 which is concerned with the preparation of starting materials. The product was purified by column chromatography using increasingly polar mixtures of hexane and ethyl acetate as eluent. There was thus obtained the required starting material (0.61 g, 48%) as an oil. NMR Spectrum (CDCl₃, δ values) 0.89 (t, 3H), 2.35 (m, 2H), 3.5 (broad s, 1H), 7.2-7.55 (m, 7H), 7.63-7.85 (m, 6H). Example 35 A solution of potassium peroxymonosulphate (0.78 g) in water (3 ml) was added to a solution of 2-[1-methoxy-1-(3-(naphth-2-ylthio)phenyl)propyl]thiazole (0.49 g) in ethanol (10 ml) which had been cooled to 0°C. The mixture was stirred at 0°C for 15 minutes. The mixture was partitioned between chloroform and water. The organic phase was dried (MgSO₄) and evaporated. The residue was purified by column chromatography using increasingly polar mixtures of hexane and ethyl acetate as eluent. There was thus obtained 2-[1-methoxy-1-(3-(naphth-2-ylsulphinyl)phenyl)propyl]thiazole as an oil (0.35 g), in 67% yield. NMR Spectrum (CDCl₃, δ values) 0.7 (t, 3H), 2.4 (m, 1H), 2.65 (m, 1H), 3.18 (d, 3H), 7.22 (m, 1H), 7.35-7.65 (m, 7H), 7.8-7.95 (m, 4H), 8.35 (s, 1H). Example 36 The procedure described in Example 35 was repeated except that a solution of potassium peroxymonosulphate (1.16 g) in water (6 ml) was employed. There was thus obtained 2-[1-methoxy-1-(3-naphth-2-ylsulphonyl)phenyl)propyl]thiazole (0.33 g, 60%), m.p. 103-107°C. Example 37 Using a similar procedure to that described in Example 4,2-[1-hydroxy-1-(5-(naphth-2-yloxy)pyrid-3-yl)propyl]thiazole was reacted with methyl iodide to give 2-[1-methoxy-1-(5-(naphth-2-yloxy)pyrid-3-yl)propyl]thiazole as an oil in 54% yield. NMR Spectrum (CDCl₃, δ values) 0.8 (t, 3H), 2.47 (m, 1H), 2.67 (m, 1H), 3.28 (s, 3H), 7.22 (doublet of doublets, 1H), 7.32 (d, 1H), 7.33 (d, 1H), 7.4-7.53 (m, 2H), 7.62 (t, 1H), 7.68 (doublet of doublets, 1H), 7.7 (d, 1H), 7.85 (m, 2H), 8.29 (d, 1H), 8.49 (d, 1H). The 2-[1-hydroxy-1-(5-naphth-2-yloxy)pyrid-3-yl)propyl]thiazole used as a starting material was obtained as follows:- The procedure described in the portion of Example 4 which is concerned with the preparation of starting materials was repeated except that 2-naphthol was used in place of 2-naphthylmethanol. There were thus obtained in turn 3-bromo-5-(naphth-2-yloxy)pyridine in 35% yield, m.p. 74-75°C, and the required starting material as an oil, in 70% yield. Example 38 The following illustrate representative pharmaceutical dosage forms containing the compound of formula I, or a (1-4C)alkoxycarbonyl derivative thereof, or a pharmaceutically-acceptable salt salt thereof (hereafter compound X),for therapeutic or prophylactic use in humans:- (a) Tablet I mg/tablet Compound X 100 Lactose Ph.Eur 182.75 Croscarmellose sodium 12.0 Maize starch paste (5% w/v paste) 2.25 Magnesium stearate 3.0 (b) Tablet II mg/tablet Compound X 50 Lactose Ph.Eur 223.75 Croscarmellose sodium 6.0 Maize starch 15.0 Polyvinylpyrrolidone (5% w/v paste) 2.25 Magnesium stearate 3.0 (c) Tablet III mg/tablet Compound X 1.0 Lactose Ph.Eur 93.25 Croscarmellose sodium 4.0 Maize starch paste (5% w/v paste) 0.75 Magnesium stearate 1.0 (d) Capsule mg/capsule Compound X 10 mg Lactose Ph.Eur 488.5 Magnesium stearate 1.5 (e) Injection I (50 mg/ml) Compound X 5.0% w/v 1M Sodium hydroxide solution 15.0% v/v 0.1M Hydrochloric acid (to adjust pH to 7.6) Polyethylene glycol 400 4.5% w/v Water for injection to 100% (f) Injection II (10 mg/ml) Compound X 1.0% w/v Sodium phosphate EP 3.6% w/v 0.1M Sodium hydroxide solution 15.0% v/v Water for injection to 100% (g) Injection III (1mg/ml, buffered to pH6) Compound X 0.1% w/v Sodium phosphate BP 2.26% w/v Citric acid 0.38% w/v Polyethylene glycol 400 3.5% w/v Water for injection to 100% (h) Aerosol I mg/ml Compound X 10.0 Sorbitan trioleate 13.5 Trichlorofluoromethane 910.0 Dichlorodifluoromethane 490.0 (i) Aerosol II mg/ml Compound X 0.2 Sorbitan trioleate 0.27 Trichlorofluoromethane 70.0 Dichlorodifluoromethane 280.0 Dichlorotetrafluoroethane 1094.0 (j) Aerosol III mg/ml Compound X 2.5 Sorbitan trioleate 3.38 Trichlorofluoromethane 67.5 Dichlorodifluoromethane 1086.0 Dichlorotetrafluoroethane 191.6 (k) Aerosol IV mg/ml Compound X 2.5 Soya lecithin 2.7 Trichlorofluoromethane 67.5 Dichlorodifluoromethane 1086.0 Dichlorotetrafluoroethane 191.6 Note The above formulations may be obtained by conventional procedures well known in the pharmaceutical art. The tablets (a)-(c) may be enteric coated by conventional means, for example to provide a coating of cellulose acetate phthalate. The aerosol formulations (h)-(k) may be used in conjunction with standard, metered dose aerosol dispensers, and the suspending agents sorbitan trioleate and soya lecithin may be replaced by an alternative suspending agent such as sorbitan monooleate, sorbitan sesquioleate, polysorbate 80, polyglycerol oleate or oleic acid.

Claims: Claims for the following Contracting States : AT, BE, CH, DE, FR, GB, IT, LI, LU, NL, SE A thiazole of the formula I wherein Ar¹ is aryl of up to 10 carbon atoms which may optionally bear one or more substituents selected from halogeno, amino, hydroxy, cyano, formyl, carbamoyl, (1-6C)alkyl, (2-6C)alkenyl, (2-6C)alkynyl, (1-6C)alkoxy, (1-6C)alkylthio, (1-6C)alkylsulphinyl, (1-6C)alkylsulphonyl, (1-6C)alkylamino, di-[(1-4C)alkyl]amino, (1-4C)alkoxycarbonyl, N-[(1-6C)alkyl]carbamoyl, N,N-di-[(1-4C)alkyl]carbamoyl, (2-6C)alkanoyl, (2-6C)alkanoylamino, (1-4C)alkylureido, hydroxy-(1-4C)alkyl and fluoro-(1-4C)alkyl; wherein A is a direct link to X, or is (1-6C)alkylene, (3-6C)alkenylene, (3-6C)alkynylene or cyclo(3-6C)alkylene; wherein X is oxy, thio, sulphinyl, sulphonyl or imino; wherein Ar² is phenylene which may optionally bear one or two substituents selected from halogeno, hydroxy, amino, nitro, cyano, carbamoyl, (1-6C)alkyl, (1-6C)alkoxy, (3-4C)alkenyloxy, (1-6C)alkylthio, (1-6C)alkylsulphinyl, (1-6C)alkysulphonyl, (1-6C)alkylamino, di-[(1-4C)alkyl]amino, (1-4C)alkoxycarbonyl, N-[(1-6C)alkyl]carbamoyl, N,N-di-[(1-4C)alkyl]carbamoyl, (2-6C)alkanoylamino, fluoro-(1-4C)alkoxy, hydroxy-(2-4C)alkoxy, (1-4C)alkoxy-(2-4C)alkoxy, amino-(2-4C)alkoxy, cyano-(1-4C)alkoxy, carbamoyl-(1-4C)alkoxy, (1-6C)alkylamino-(2-4C)alkoxy, di-[(1-4C)alkyl]amino-(2-4C)alkoxy, (1-4C)alkoxycarbonyl-(1-4C)alkoxy, N-[(1-6C)alkyl]carbamoyl(1-4C)alkoxy, N,N-[di(1-4C)alkyl]carbamoyl-(1-4C)alkoxy, fluoro-(1-4C)alkyl, hydroxy-(1-4C)alkyl, amino-(1-4C)alkyl, cyano-(1-4C)alkyl, (1-4C)alkoxy-(1-4C)alkyl, (1-4C)alkylamino-(1-4C)alkyl, di-[(1-4C)alkyl]amino-(1-4C)alkyl, (2-6C)alkanoylamino-(1-4C)alkyl, (1-4C)alkoxycarbonyl-(1-4C)alkylamino, carbamoyl-(1-4C)alkylamino, cyano-(1-4C)alkylamino, hydroxy-(2-4C)alkylamino and (1-4C)alkylsulphonamido, or Ar² is a 6-membered heterocyclene moiety containing up to three nitrogen atoms which may optionally bear one or two substituents selected from halogeno, hydroxy, amino, cyano, (1-6C)alkyl, (1-6C)alkoxy, (1-6C)alkylamino and di-[(1-4C)alkyl]amino; wherein R¹ is hydrogen, (1-6C)alkyl, (2-6C)alkenyl, (2-6C)alkynyl, fluoro-(1-4C)alkyl, cyano-(1-4C)alkyl, hydroxy-(1-4C)alkyl, (1-4C)alkoxy-(1-4C)alkyl and (2-4C)alkanoyloxy-(1-4C)alkyl; wherein R² is hydrogen, (1-6C)alkyl, (3-6C)alkenyl, (3-6C)alkynyl, fluoro-(1-4C)alkyl, (1-4C)alkylthio-(1-4C)alkyl, cyano-(1-4C)alkyl, (1-4C)alkoxycarbonyl-(1-4C)alkyl, carboxy-(1-4C)alkyl, carbamoyl-(1-4C)alkyl or (2-6C)alkanoyl or R² is benzoyl which may optionally bear a substituent selected from halogeno, (1-6C)alkyl or (1-6C)alkoxy; and wherein Q is thiazolyl which may optionally bear one or two substituents selected from halogeno, amino, nitro, cyano, (1-6C)alkyl, (1-6C)alkoxy, (1-6C)alkylamino, di-[(1-4C)alkyl]amino, (1-4C)alkoxycarbonyl, (2-6C)alkanoyl, (2-6C)alkanoylamino, (1-4C)alkoxycarbonylamino, fluoro-(1-4C)alkyl and hydroxy-(1-4C)alkyl; or a pharmaceutically-acceptable salt thereof. A thiazole of the formula I as claimed in claim 1 wherein Ar¹ is phenyl, naphth-1-yl or naphth-2-yl which may optionally bear one, two or three substituents selected from fluoro, chloro, amino, hydroxy, cyano, formyl, carbamoyl, methyl, methoxy, methylthio, methylsulphinyl, methylsulphonyl, methoxycarbonyl, acetamido, difluoromethyl and trifluoromethyl; A is a direct link to X, or is methylene, 1-propenylene, 2-methylprop-1-enylene or 1-propynylene; X is oxy, thio, sulphinyl or sulphonyl; Ar² is 1,3-phenylene or 1,4-phenylene which may optionally bear one substituent selected from fluoro, hydroxy, amino, nitro, cyano, carbamoyl, methyl, methoxy, allyloxy, methylamino, dimethylamino, tert -butoxycarbonyl, acetamido, cyanomethoxy, carbamoylmethoxy, ethoxycarbonylmethoxy, trifluoromethyl, carbamoylmethylamino, cyanomethylamino, 2-hydroxyethylamino and methanesulphonamido, or Ar² is 2,4-, 2,5- or 3,5-pyridylene, or 4,6-pyrimidinylene; R¹ is methyl, ethyl, propyl, vinyl, ethynyl, 2-propynyl, trifluoromethyl, cyanomethyl, hydroxymethyl, methoxymethyl or acetoxymethyl; R² is methyl, ethyl, allyl, 2-propynyl, 2-fluoroethyl, 2,2-difluoroethyl, methylthiomethyl or cyanomethyl; and Q is 2-, 4- or 5-thiazolyl which may optionally bear one substituent selected from chloro, methyl and methoxycarbonyl; or a pharmaceutically-acceptable salt thereof. A thiazole of the formula I as claimed in claim 1 wherein Ar¹ is phenyl, naphth-2-yl, 3,4-dichlorophenyl, 3-iodophenyl, 3-cyanophenyl, 3,4-dimethoxyphenyl, 3,4,5-trimethoxyphenyl, 4-methylthiophenyl, 4-methylsulphinylphenyl, 3-trifluoromethylphenyl, 6-fluoronaphth-2-yl or 5-cyanonaphth-2-yl; A is methylene, 1-propenylene, 2-methylprop-1-enylene or 1-propynylene; X is oxy; Ar² is 1,3-phenylene, 5-hydroxy-1,3-phenylene, 5-amino-1,3-phenylene, 5-nitro-1,3-phenylene, 4-methyl-1,3-phenylene, 5-methoxy-1,3-phenylene, 5-cyanomethoxy-1,3-phenylene,5-carbamoylmethoxy-1,3-phenylene, 2,5-pyridylene, 3,5-pyridylene, 2,6-pyridylene or 4,6-pyrimidinylene; R¹ is hydrogen, methyl, ethyl, propyl, vinyl, trifluoromethyl, hydroxymethyl, methoxymethyl or acetoxymethyl; R² is hydrogen or methyl; and Q is 2-thiazolyl or 4-thiazolyl; or a pharmaceutically-acceptable salt thereof. A thiazole of the formula I as claimed in claim 1 wherein Ar¹ is phenyl, naphth-1-yl, naphth-2-yl, 2-fluorophenyl, 3-fluorophenyl, 4-fluorophenyl, 3,4-difluorophenyl, 6-fluoronaphth-2-yl, 7-fluoronaphth-2-yl, 2-chlorophenyl, 3-chlorophenyl, 2-tolyl, 6-methylnaphth-2-yl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-methylthiophenyl, 3-methoxycarbonylphenyl, 2-trifluoromethylphenyl, 3-trifluoromethylphenyl or 7-difluoromethylnaphth-2-yl; A is a direct link to X, or is methylene, 1-propenylene or 1-propynylene; X is oxy or thio; Ar² is 1,3-phenylene, 5-fluoro-1,3-phenylene, 5-methoxy-1,3-phenylene, 2-methoxy-1,4-phenylene, 5-cyanomethoxy-1,3-phenylene, 5-trifluoromethyl-1,3-phenylene or 3,5-pyridylene; R¹ is methyl or ethyl; R² is methyl, ethyl, allyl, 2-propynyl or cyanomethyl; and Q is 2-thiazolyl; or a pharmaceutically-acceptable salt thereof. A thiazole of the formula I as claimed in claim 1 wherein Ar¹ is phenyl, naphth-1-yl, 2-fluorophenyl, 3-fluorophenyl, 4-fluorophenyl, 3,4-difluorophenyl, 2-chlorophenyl, 3-chlorophenyl, 2-tolyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 3-methoxycarbonylphenyl, 2-trifluoromethylphenyl or 3-trifluoromethylphenyl; A is 1-propynylene; X is oxy; Ar² is 1,3-phenylene, 5-fluoro-1,3-phenylene, 5-methoxy-1,3-phenylene, 2-methoxy-1,4-phenylene or 5-trifluoromethyl-1,3-phenylene; R¹ is methyl or ethyl; R² is methyl; and Q is 2-thiazolyl; or a pharmaceutically-acceptable salt thereof. A thiazole selected from the group consisting of 2-[1-methoxy-1-[3-(naphth-2-ylmethoxy)phenyl]propyl]thiazole; 2-[1-methoxy-1-[5-(naphth-2-ylmethoxy)pyrid-3-yl]propyl]thiazole; 2-[1-methoxy-1-[3-(3-phenylprop-2-ynyloxy)phenyl]propyl]thiazole; 2-[1-methoxy-1-(3-(6-methylnaphth-2-ylmethoxy)phenyl)propyl]thiazole; 2-[1-methoxy-1-(5-methoxy-3-(naphth-2-ylmethoxy)phenyl)propyl]thiazole; 2-[1-methoxy-1-(3-(naphth-2-ylmethoxy)-5-trifluoromethylphenyl)propyl]thiazole; 2-[1-ethoxy-1-(3-(naphth-2-ylmethoxy)-5-trifluoromethylphenyl)propyl]thiazole; 2-[1-allyloxy-1-(5-methoxy-3-(naphth-2-ylmethoxy)phenyl)propyl]thiazole; 2-[1-(5-methoxy-3-(naphth-2-ylmethoxy)phenyl)-1-(propy-2-ynyloxy)propyl]thiazole; 2-[1-methoxy-1-[3-methoxy-(4-(3-phenylprop-2-ynyloxy)phenyl]propyl]thiazole; 2-[1-[3-(3-(3-chlorophenyl)prop-2-ynyloxy)phenyl]-1-methoxypropyl]thiazole; 2-[1-[3-(3-(2-fluorophenyl)prop-2-ynyloxy)phenyl]-1-methoxypropyl]thiazole; 2-[1-[3-(3-(3-fluorophenyl)prop-2-ynyloxy)phenyl]-1-methoxypropyl]thiazole; 2-[1-[3-(3-(4-fluorophenyl)prop-2-ynyloxy)phenyl]-1-methoxypropyl]thiazole; 2-[1-methoxy-1-[3-(3-(naphth-1-yl)prop-2-ynyloxy)phenyl]propyl]thiazole; 2-[1-cyanomethoxy-1-(5-methoxy-3-(naphth-2-ylmethoxy)phenyl)propyl]thiazole; and 2-[1-methoxy-1-(3-(naphth-2-ylthio)phenyl)propyl]thiazole; or a pharmaceutically-acceptable salt thereof. A process for the manufacture of a thiazole of the formula I, or a pharmaceutically-acceptable salt thereof, as claimed in any one of claims 1 to 5 which comprises; (a) the alkylation, in the presence of a suitable base, of a compound of the formula II with a compound of the formula Ar¹-A-Z wherein Z is a displaceable group; provided that, when there is an amino, alkylamino, hydroxy or carboxy group in Ar¹, Ar², R¹ or Q, any amino, alkylamino or carboxy group is protected by a conventional protecting group and any hydroxy group may be protected by a conventional protecting group or alternatively any hydroxy group need not be protected; whereafter any undesired protecting group in Ar¹, Ar², R¹ or Q is removed by conventional means; (b) the alkylation, in the presence of a suitable base, of a compound of the formula V with a compound of the formula R²-Z, wherein R² and Z have the meanings defined hereinbefore, provided that, when there is an amino, imino, alkylamino, hydroxy or carboxy group in Ar¹, X, Ar², R¹ or Q, any amino, imino, alkylamino, hydroxy or carboxy group is protected by a conventional protecting group; whereafter any undesired protecting group in Ar¹, X, Ar², R¹ or Q is removed by conventional means; (c) for the production of those compounds of the formula I wherein A is a (3-6C)alkynylene group, the coupling, in the presence of a suitable organometallic catalyst, of a compound of the formula Ar¹-Z wherein Ar¹ has the meaning defined hereinbefore and Z is a halogeno group, with an ethynyl compound of the formula VI, wherein A¹ is (1-4C)alkylene and X, Ar², R¹, R² and Q have the meanings defined hereinbefore; (d) for the production of those compounds of the formula I wherein Ar¹ or Ar² bears an alkylsulphinyl or alkylsulphonyl substituent or X is a sulphinyl or sulphonyl group, the oxidation of a compound of the formula I wherein Ar¹ or Ar² bears an alkylthio substituent or wherein X is a thio group; (e) for the production of those compounds of the formula I wherein Ar¹, Ar² or Q bears an alkanoylamino or alkanoylaminoalkyl substituent, the acylation of a compound of the formula I wherein Ar¹, Ar² or Q bears an amino or aminoalkyl substituent; (f) for the production of those compounds of the formula I wherein R² is alkanoyl or benzoyl optionally bearing a substituent as defined hereinbefore, the acylation of a compound of the formula I wherein R² is hydrogen; (g) for the production of those compounds of the formula I wherein Ar¹ or Ar² bears an alkenyl substituent, A is alkenylene or R¹ is alkenyl, the reduction of the corresponding compound wherein Ar¹ or Ar² bears an alkynyl substituent, A is alkynylene or R¹ is alkynyl; (h) for the production of those compounds of the formula I wherein Ar² bears an alkoxy or substituted alkoxy substituent, or an alkylamino or substituted alkylamino substituent, the alkylation of a compound of the formula I wherein Ar² bears a hydroxy or amino substituent; or (i) for the production of those compounds of the formula I wherein Ar¹, Ar² or Q bears an amino substituent, the reduction of a compound of the formula I wherein Ar¹, Ar² or Q bears a nitro substituent; and when a pharmaceutically-acceptable salt of a novel compound of the formula I is required, it may be obtained by reaction of said compound with a suitable acid or base using a conventional procedure. A pharmaceutical composition which comprises a thiazole of the formula I as claimed in any one of claims 1 to 5, or a pharmaceutically-acceptable salt thereof, in association with a pharmaceutically-acceptable diluent or carrier, A pharmaceutical composition which comprises a thiazole of the formula I as claimed in any one of claims 1 to 5, or a pharmaceutically-acceptable salt thereof, in conjunction or admixture with a cyclooxygenase inhibitory non-steroidal anti-inflammatory agent, and a pharmaceutically-acceptable diluent or carrier. A thiazole of the formula I as claimed in any one of claims 1 to 5, or a pharmaceutically-acceptable salt thereof, for use in medicine. Claims for the following Contracting States : GR, ES A process for the manufacture of a thiazole of the formula I wherein Ar¹ is aryl of up to 10 carbon atoms which may optionally bear one or more substituents selected from halogeno, amino, hydroxy, cyano, formyl, carbamoyl, (1-6C)alkyl, (2-6C)alkenyl, (2-6C)alkynyl, (1-6C)alkoxy, (1-6C)alkylthio, (1-6C)alkylsulphinyl, (1-6C)alkylsulphonyl, (1-6C)alkylamino, di-[(1-4C)alkyl]amino, (1-4C)alkoxycarbonyl, N-[(1-6C)alkyl]carbamoyl, N,N-di-[(1-4C)alkyl]carbamoyl, (2-6C)alkanoyl, (2-6C)alkanoylamino, (1-4C)alkylureido, hydroxy-(1-4C)alkyl and fluoro-(1-4C)alkyl; wherein A is a direct link to X, or is (1-6C)alkylene, (3-6C)alkenylene, (3-6C)alkynylene or cyclo(3-6C)alkylene; wherein X is oxy, thio, sulphinyl, sulphonyl or imino; wherein Ar² is phenylene which may optionally bear one or two substituents selected from halogeno, hydroxy, amino, nitro, cyano, carbamoyl, (1-6C)alkyl, (1-6C)alkoxy, (3-4C)alkenyloxy, (1-6C)alkylthio, (1-6C)alkylsulphinyl, (1-6C)alkysulphonyl, (1-6C)alkylamino, di-[(1-4C)alkyl]amino, (1-4C)alkoxycarbonyl, N-[(1-6C)alkyl]carbamoyl, N,N-di-[(1-4C)alkyl]carbamoyl, (2-6C)alkanoylamino, fluoro-(1-4C)alkoxy, hydroxy-(2-4C)alkoxy, (1-4C)alkoxy-(2-4C)alkoxy, amino-(2-4C)alkoxy, cyano-(1-4C)alkoxy, carbamoyl-(1-4C)alkoxy, (1-6C)alkylamino-(2-4C)alkoxy, di-[(1-4C)alkyl]amino-(2-4C)alkoxy, (1-4C)alkoxycarbonyl-(1-4C)alkoxy, N-[(1-6C)alkyl]carbamoyl-(1-4C)alkoxy, N,N-[di(1-4C)alkyl]carbamoyl-(1-4C)alkoxy, fluoro-(1-4C)alkyl, hydroxy-(1-4C)alkyl, amino-(1-4C)alkyl, cyano-(1-4C)alkyl, (1-4C)alkoxy-(1-4C)alkyl, (1-4C)alkylamino-(1-4C)alkyl, di-[(1-4C)alkyl]amino-(1-4C)alkyl, (2-6C)alkanoylamino-(1-4C)alkyl, (1-4C)alkoxycarbonyl-(1-4C)alkylamino, carbamoyl-(1-4C)alkylamino, cyano-(1-4C)alkylamino, hydroxy-(2-4C)alkylamino and (1-4C)alkylsulphonamido, or Ar² is a 6-membered heterocyclene moiety containing up to three nitrogen atoms which may optionally bear one or two substituents selected from halogeno, hydroxy, amino, cyano, (1-6C)alkyl, (1-6C)alkoxy, (1-6C)alkylamino and di-[(1-4C)alkyl]amino; wherein R¹ is hydrogen, (1-6C)alkyl, (2-6C)alkenyl, (2-6C)alkynyl, fluoro-(1-4C)alkyl, cyano-(1-4C)alkyl, hydroxy-(1-4C)alkyl, (1-4C)alkoxy-(1-4C)alkyl and (2-4C)alkanoyloxy-(1-4C)alkyl; wherein R² is hydrogen, (1-6C)alkyl, (3-6C)alkenyl, (3-6C)alkynyl, fluoro-(1-4C)alkyl, (1-4C)alkylthio-(1-4C)alkyl, cyano-(1-4C)alkyl, (1-4C)alkoxycarbonyl-(1-4C)alkyl, carboxy-(1-4C)alkyl, carbamoyl-(1-4C)alkyl or (2-6C)alkanoyl or R² is benzoyl which may optionally bear a substituent selected from halogeno, (1-6C)alkyl or (1-6C)alkoxy; and wherein Q is thiazolyl which may optionally bear one or two substituents selected from halogeno, amino, nitro, cyano, (1-6C)alkyl, (1-6C)alkoxy, (1-6C)alkylamino, di-[(1-4C)alkyl]amino, (1-4C)alkoxycarbonyl, (2-6C)alkanoyl, (2-6C)alkanoylamino, (1-4C)alkoxycarbonylamino, fluoro-(1-4C)alkyl and hydroxy-(1-4C)alkyl; or a pharmaceutically-acceptable salt thereof, characterised by, (a) the alkylation, in the presence of a suitable base, of a compound of the formula II with a compound of the formula Ar¹-A-Z wherein Z is a displaceable group; provided that, when there is an amino, alkylamino, hydroxy or carboxy group in Ar¹, Ar², R¹ or Q, any amino, alkylamino or carboxy group is protected by a conventional protecting group and any hydroxy group may be protected by a conventional protecting group or alternatively any hydroxy group need not be protected; whereafter any undesired protecting group in Ar¹, Ar², R¹ or Q is removed by conventional means; (b) the alkylation, in the presence of a suitable base, of a compound of the formula V with a compound of the formula R²-Z, wherein R² and Z have the meanings defined hereinbefore, provided that, when there is an amino, imino, alkylamino, hydroxy or carboxy group in Ar¹, X, Ar², R¹ or Q, any amino, imino, alkylamino, hydroxy or carboxy group is protected by a conventional protecting group; whereafter any undesired protecting group in Ar¹, X, Ar², R¹ or Q is removed by conventional means; (c) for the production of those compounds of the formula I wherein A is a (3-6C)alkynylene group, the coupling, in the presence of a suitable organometallic catalyst, of a compound of the formula Ar¹-Z wherein Ar¹ has the meaning defined hereinbefore and Z is a halogeno group, with an ethynyl compound of the formula VI, wherein A¹ is (1-4C)alkylene and X, Ar², R¹, R² and Q have the meanings defined hereinbefore; (d) for the production of those compounds of the formula I wherein Ar¹ or Ar² bears an alkylsulphinyl or alkylsulphonyl substituent or X is a sulphinyl or sulphonyl group, the oxidation of a compound of the formula I wherein Ar¹ or Ar² bears an alkylthio substituent or wherein X is a thio group; (e) for the production of those compounds of the formula I wherein Ar¹, Ar² or Q bears an alkanoylamino or alkanoylaminoalkyl substituent, the acylation of a compound of the formula I wherein Ar¹, Ar² or Q bears an amino or aminoalkyl substituent; (f) for the production of those compounds of the formula I wherein R² is alkanoyl or benzoyl optionally bearing a substituent as defined hereinbefore, the acylation of a compound of the formula I wherein R² is hydrogen; (g) for the production of those compounds of the formula I wherein Ar¹ or Ar² bears an alkenyl substituent, A is alkenylene or R¹ is alkenyl, the reduction of the corresponding compound wherein Ar¹ or Ar² bears an alkynyl substituent, A is alkynylene or R¹ is alkynyl; (h) for the production of those compounds of the formula I wherein Ar² bears an alkoxy or substituted alkoxy substituent, or an alkylamino or substituted alkylamino substituent, the alkylation of a compound of the formula I wherein Ar² bears a hydroxy or amino substituent; or (i) for the production of those compounds of the formula I wherein Ar¹, Ar² or Q bears an amino substituent, the reduction of a compound of the formula I wherein Ar¹, Ar² or Q bears a nitro substituent; and when a pharmaceutically-acceptable salt of a novel compound of the formula I is required, it may be obtained by reaction of said compound with a suitable acid or base using a conventional procedure. A process as claimed in claim 1 for the manufacture of a thiazole of the formula I wherein Ar¹ is phenyl, naphth-1-yl or naphth-2-yl which may optionally bear one, two or three substituents selected from fluoro, chloro, amino, hydroxy, cyano, formyl, carbamoyl, methyl, methoxy, methylthio, methylsulphinyl, methylsulphonyl, methoxycarbonyl, acetamido, difluoromethyl and trifluoromethyl; A is a direct link to X, or is methylene, 1-propenylene, 2-methylprop-1-enylene or 1-propynylene; X is oxy, thio, sulphinyl or sulphonyl; Ar² is 1,3-phenylene or 1,4-phenylene which may optionally bear one substituent selected from fluoro, hydroxy, amino, nitro, cyano, carbamoyl, methyl, methoxy, allyloxy, methylamino, dimethylamino, tert -butoxycarbonyl, acetamido, cyanomethoxy, carbamoylmethoxy, ethoxycarbonylmethoxy, trifluoromethyl, carbamoylmethylamino, cyanomethylamino, 2-hydroxyethylamino and methanesulphonamido, or Ar² is 2,4-, 2,5- or 3,5-pyridylene, or 4,6-pyrimidinylene; R¹ is methyl, ethyl, propyl, vinyl, ethynyl, 2-propynyl, trifluoromethyl, cyanomethyl, hydroxymethyl, methoxymethyl or acetoxymethyl; R² is methyl, ethyl, allyl, 2-propynyl, 2-fluoroethyl, 2,2-difluoroethyl, methylthiomethyl or cyanomethyl; and Q is 2-, 4- or 5-thiazolyl which may optionally bear one substituent selected from chloro, methyl and methoxycarbonyl; or a pharmaceutically-acceptable salt thereof. A process as claimed in claim 1 for the manufacture of a thiazole of the formula I wherein Ar¹ is phenyl, naphth-2-yl, 3,4-dichlorophenyl, 3-iodophenyl, 3-cyanophenyl, 3,4-dimethoxyphenyl, 3,4,5-trimethoxyphenyl, 4-methylthiophenyl, 4-methylsulphinylphenyl, 3-trifluoromethylphenyl, 6-fluoronaphth-2-yl or 5-cyanonaphth-2-yl; A is methylene, 1-propenylene, 2-methylprop-1-enylene or 1-propynylene; X is oxy; Ar² is 1,3-phenylene, 5-hydroxy-1,3-phenylene, 5-amino-1,3-phenylene, 5-nitro-1,3-phenylene, 4-methyl-1,3-phenylene, 5-methoxy-1,3-phenylene, 5-cyanomethoxy-1,3-phenylene, 5-carbamoylmethoxy-1,3-phenylene, 2,5-pyridylene, 3,5-pyridylene, 2,6-pyridylene or 4,6-pyrimidinylene; R¹ is hydrogen, methyl, ethyl, propyl, vinyl, trifluoromethyl, hydroxymethyl, methoxymethyl or acetoxymethyl; R² is hydrogen or methyl; and Q is 2-thiazolyl or 4-thiazolyl; or a pharmaceutically-acceptable salt thereof. A process as claimed in claim 1 for the manufacture of a thiazole of the formula I wherein Ar¹ is phenyl, naphth-1-yl, naphth-2-yl, 2-fluorophenyl, 3-fluorophenyl, 4-fluorophenyl, 3,4-difluorophenyl, 6-fluoronaphth-2-yl, 7-fluoronaphth-2-yl, 2-chlorophenyl, 3-chlorophenyl, 2-tolyl, 6-methylnaphth-2-yl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-methylthiophenyl, 3-methoxycarbonylphenyl, 2-trifluoromethylphenyl, 3-trifluoromethylphenyl or 7-difluoromethylnaphth-2-yl; A is a direct link to X, or is methylene, 1-propenylene or 1-propynylene; X is oxy or thio; Ar² is 1,3-phenylene, 5-fluoro-1,3-phenylene, 5-methoxy-1,3-phenylene, 2-methoxy-1,4-phenylene, 5-cyanomethoxy-1,3-phenylene, 5-trifluoromethyl-1,3-phenylene or 3,5-pyridylene; R¹ is methyl or ethyl; R² is methyl, ethyl, allyl, 2-propynyl or cyanomethyl; and Q is 2-thiazolyl; or a pharmaceutically-acceptable salt thereof. A process as claimed in claim 1 for the manufacture of a thiazole of the formula I wherein Ar¹ is phenyl, naphth-1-yl, 2-fluorophenyl, 3-fluorophenyl, 4-fluorophenyl, 3,4-difluorophenyl, 2-chlorophenyl, 3-chlorophenyl, 2-tolyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 3-methoxycarbonylphenyl, 2-trifluoromethylphenyl or 3-trifluoromethylphenyl; A is 1-propynylene; X is oxy; Ar² is 1,3-phenylene, 5-fluoro-1,3-phenylene, 5-methoxy-1,3-phenylene, 2-methoxy-1,4-phenylene or 5-trifluoromethyl-1,3-phenylene; R¹ is methyl or ethyl; R² is methyl; and Q is 2-thiazolyl; or a pharmaceutically-acceptable salt thereof. A process for the manufacture of pharmaceutical composition characterised by bringing into association a thiazole of the formula I as defined in any one of claims 1 to 5, or a pharmaceutically-acceptable salt thereof, and a pharmaceutically-acceptable diluent or carrier. A process for the manufacture of pharmaceutical composition characterised by bringing into association a thiazole of the formula I as defined in any one of claims 1 to 5, or a pharmaceutically-acceptable salt thereof, a cyclooxygenase inhibitory non-steroidal anti-inflammatory agent and a pharmaceutically-acceptable diluent or carrier.

Inventors: BIRD THOMAS GEOFFREY COLERICK, CRAWLEY GRAHAM CHARLES, EDWARDS MARTIN PAUL, EDWARDS PHILIP NEIL, GIRODEAU JEAN-MARC MARIE MAURI, KINGSTON JOHN FRANCIS, BIRD, THOMAS GEOFFREY COLERICK, CRAWLEY, GRAHAM CHARLES, EDWARDS, MARTIN PAUL, EDWARDS, PHILIP NEIL, GIRODEAU, JEAN-MARC MARIE MAURICE, KINGSTON, JOHN FRANCIS
Applicants: ICI PHARMA, ICI PLC, IMPERIAL CHEMICAL INDUSTRIES PLC
Application year: 1989
Main classification: C07D277
IPC codes: A61K31, C07D417, A61P43, A61P29, A61P37, C07D277, C12N9