| abstract |
A piperazinylcarbostyril compound of the formula (I) <IMAGE> (I) wherein R1 represents a hydrogen atom, a lower alkyl group, a lower alkenyl group, a lower alkynyl group, or a phenyl-lower alkyl group; R2 represents a hydrogen atom or a lower alkoxy group; R3 represents a hydrogen atom, a lower alkanoyl group, a furoyl group, a pyridylcarbonyl group, a lower alkanesulfonyl group, a lower alkoxycarbonyl group, a lower alkoxycarbonyl-lower alkyl group, a phenylsulfonyl group which may be substituted with a lower alkyl group on the benzene ring thereof, a lower alkyl group, a lower alkenyl group, a lower alkynyl group, a phenylcarbonyl group, a phenyl-lower alkyl group or a phenyl-lower alkanoyl group where each of said phenylcarbonyl group, phenyl-lower alkyl group and phenyl-lower alkanoyl group may be substituted with 1 to 3 of a lower alkoxy group, a halogen atom, a lower alkyl group, a cyano group, a nitro group, an amino group, a hydroxy group, a lower alkanoylamino group, a lower alkylthio group and a lower alkanoyloxy group, or with a lower alkylenedioxy group on the benzene ring thereof; and the bonding between the 3- and 4-positions of the carbostyril nucleus is a single bond or a double bond; or its pharmaceutically acceptable salt, useful as a cardiotonic agent. |