Carbostyril derivatives, and antihistaminic agents containing the same

Abstract

Novel carbostyril derivatives and their salts having antihistaminic effects and are useful as antihistaminic agents, represented by the general formula (1), ##STR1## wherein R.sup.1 is a hydrogen atom, a lower alkenyl group, a lower alkynyl group or a lower alkyl group which may have phenyl group(s) as the substituted group(s); R.sup.2 is a hydrogen atom, a lower alkyl group or a phenyl group; R.sup.3 is a lower alkyl group having phenyl group(s) as the substituted group(s), or a phenyl group which may have 1 to 3 substituted groups selected from the group consisting of halogen atoms, lower alkyl groups and lower alkoxy groups; R.sup.4 is a hydrogen atom, a hydroxyl group or a lower alkanoyl group; X is a halogen atom; Y is a lower alkylene group which may have hydroxyl group(s) as the substituent(s); n is 0, 1 or 2; the carbon-carbon bond between 3- and 4-positions in the carbostyril skeleton is a single or double bond; provided that when R.sup.3 is a lower alkyl group having phenyl group(s) as the substituted group(s), then R.sup.4 should be neither a hydroxyl group nor a lower alkanoyl group.