Abstract: Novel 1(2H)-isoquinolone compounds and the acid addition salts thereof are disclosed. These compounds are useful as pharmaceutical agents in view of their anti-ulcer, stomach mucous membrane blood flow increasing, anti-hypertensive, analgesic, anti-histamine, anti-cholinergic and gastric secretion inhibitory activities.

Abstract: 1(2H)-Isoquinolone compounds represented by the formula (1) ##STR1## wherein Y represents hydrogen, chlorine or a methoxy group, Z represents a straight chain or branched chain divalent saturated aliphatic hydrocarbon group having 2 to 4 carbon atoms, R.sub.1 represents a cyano group, a lower alkoxycarbonyl group, a carbamoyl group, an N-substituted carbamoyl group, a phenyl group or a substituted phenyl group, R.sub.2 represents hydrogen or a lower alkyl group, and R.sub.3 represents a lower alkyl group, or R.sub.2 and R.sub.3 can form, when taken together with the nitrogen atom to which they are attached, a heterocyclic group, and the acid addition salts thereof, useful as analgesic, gastric secretion inhibitory, anti-depression, anti-histamine, anti-cholinergic and anti-ulcer agents.