Novel isoquinoline derivatives of the general formula ##STR1## wherein R represents a lower alkyl group, a lower cycloalkyl group, or a group of the formula ##STR2## in which R.sup.2 represents a hydrogen atom, a halogen atom, a methyl group, a trifluoromethyl group, a methoxy group, a methylamino group or a dimethylami no group;R.sup.1 represents a hydrogen atom or a lower alkyl group; andY represents a carboxyl group, a cyano group, a carbamoyl group, a lower alkoxycarbonyl group or a lower alkylaminocarbonyl group;or a salt thereof; a process for the production thereof.The above compound is useful as an anti-inflammatory and analgesic agent.