Phthalazine cardiac stimulants, processes for preparing them, and pharmaceutical compositions containing them.
Phthalazine cardiac stimulants of the formula < CHEM > wherein R<1> is a C1-C4 alkyl group, and Y is a group of the formula: -(CH2)m-Z, wherein m is 1 or 2, and Z is a group selected from: -OCONR<3>R<4>, -N(R<2>)COR<3>, -N(R<2>)SO2R<3>, -N(R<2>)CONR<3>R<4>, -N(R<2>)SO2NR<3>R<4>, and -N(R<2>)COOR<3>, wherein R<2> and R<4> are each independently hydrogen or C1-C4 alkyl, and R<3> is C3-C7 cycloalkyl or a pharmaceutically acceptable acid addition salt thereof. Also described are processes for preparing the compounds and pharmaceutical compositions containing them.