| abstract |
Heterocyclic compounds of the formula:n wherein either X is -CR 1 R 2 - and Y is -0-, -S- or -NHR 3- , wherein R 1 , R 2 and R 3 , which may be the same or different, each is hydrogen or alkyl of up to 4 carbon atoms; or X is -0-, -S- or -NH- and Y is -CR 1 R 2 - wherein R 1 and R 2 have the meanings stated above; wherein R 4 and R 5 , which may be the same or different, each is hydrogen (but provided that R 4 and R 5 are not both hydrogen), or each is a group defined in claim 1 which is readily convertible into a carboxy group; processes for their manufacture; and pharmaceutical compositions containing them. The compounds possess cardiotonic and/or antihypertensive activity. |