This invention relates to new heterocyclic compounds, compositions, process of making and method of use thereof for inhibition of platelet aggregation, vasodilation, antihypertensive activity and prostaglandin I.sub.2 agonist.
Heterocyclic compounds of the formula:
wherein
R1 is carboxy or protected carboxy,
R2 is aryl which may have suitable substituent(s),
R3 is aryl which may have suitable substituent(s),
R4 is hydrogen, lower alkyl, hydroxy or aryl,
A1 is lower alkylene,
etc.,
etc. and
n is 0 or 1,
and pharmaceutically acceptable salts thereof which are useful as a medicament.