HETEROCYCLIC DERIVATIVES OF PYRIDAZINONE, THIADIAZINONE, OXADIAZINONE AND TRIAZINONE

摘要

Heterocyclic compounds of the formula: IMAGE wherein A is a direct link, or is alkylene of 1 to 4 carbon atoms or alkenylene of 2 to 4 carbon atoms; wherein either X is -CR1R2- and Y is -O-, -S- or -NR3-, wherein R1, R2 and R3, which may be the same or different, each is hydrogen or alkyl of up to 4 carbon atoms; or X is -O-, -S- or -NH- and Y is -CR1R2- wherein R1 and R2 have the meanings stated above; and wherein Het is a 5- or 6-membered heterocyclic ring containing 1, 2 or 3 heteroatoms selected from nitrogen, oxygen or sulphur atoms, which ring may be unsubstituted or may bear one or two substituents as set out in claim 1, provided that when X is -CR1R2- and A is a direct link, Het is not unsubstituted 2-furyl; and salts thereof where appropriate; processes for their manufacture and pharmaceutical compositions containing them. The compounds possess cardiotonic and/or antihypertensive activity.