Carbostyril derivatives and their salts

摘要

Carbostyril derivatives of the general formula <IMAGE> wherein R1 is a hydrogen atom, a lower alkyl group, a lower alkenyl group, a lower alkynyl group or a phenyl-lower alkyl group and R2 and R3 may be the same or different and each is a substituted or unsubstituted lower alkyl group, or R2 and R3 may form, together with the adjacent nitrogen atom, a 5- or 6-membered saturated heterocyclic ring which may be substituted or unsubstituted. The derivatives are useful as the active ingredient in cardiotonic compositions.