3(2h)pyridazinones for antagonistic agent against srs-a

Abstract

A 3(2H)pyridazinone of the formula: ##STR1## wherein R.sub.1 is hydrogen, 2-propenyl, or straight chained or branched C.sub.1 -C.sub.4 alkyl; each of R.sub.2 and R.sub.3 which may be the same or different, is hydrogen, or straight chained or branched C.sub.1 -C.sub.3 alkyl; X is chlorine, or bromine; Y is hydrogen, halogen, nitro, amino, or --AR.sub.4 wherein A is oxygen, or sulfur, and R.sub.4 is hydroen, straight chained, branched or cyclic C.sub.1 -C.sub.8 alkyl, ##STR2## wherein R.sub.5 is hydrogen, or straight chained or branched C.sub.1 -C.sub.4 alkyl; and Ar is ##STR3## wherein each Z.sub.1 and Z.sub.2 which may be the same or different, is hydrogen, halogen, straight or branched C.sub.1 -C.sub.4 alkyl, or --OR.sub.6 wherein R.sub.6 is straight or branched C.sub.1 -C.sub.4 alkyl, and B is oxygen, sulfur, or --N.dbd.C-- (to form a quinoline or pyridine ring); or a pharamaceutically acceptable salt thereof.