| abstract |
Compounds of the general formula:n wherein R is hydrogen, C 1 -C 4 alkyl, or halogen;n Y is (CH 2 )n, where n is 1 to 4, benzyl or CH 2 -(Het)- where Het represents a 5 or 6 membered aromatic heterocyclic ring linkedto Z by a ring carbon atom; Z is CO 2 R 1 , CONHR 2 , CON(R 3 ) 2 , COCO 2 R 1 , COCONHR 2 , COCON(R') 2 , CN or 5-tetrazolyl, or, when Y is -CH 2 -(Het),C 1 -C 4 alkyl, where: R 1 is H or C 1 -C 4 alkyl, R 2 is H, C 1 -C 4 alkyl, C 2 -C 4 alkanoyl, C 1 -C 4 alkylsulphonyl, CN, benzoyl or benzenesulphonyl, the phenyl ring in said benzoyl or benzenesulphonyl groups being optionally substituted, each R 3 is C 1 -C 4 alkyl or two groups R 3 together with the nitrogen atom to which they are attached form a pyrrolidino, piperidino or morpholino group; the group -O-Y-Z being attached to the 3 or 5 position of the pyridine ring, and the pharmaceutically acceptable salts thereof and bioprecursors therefor are able to selectively inhibit the action of the thromboxane synethetase enzyme without significantly inhibiting the action of the prostacycline synthetase or cyclooxygenase enzymes and are thus useful in the treatment of ischaemic heart disease, stroke, transient ischaemic attack, thrombosis, migraine and the vascular complications of diabetes. |