Antiallergic agents. IV - Substituted 2-benzylidene-3(2H)-benzofuranone-5-carboxylic acids

A series of substituted 2-benzylidene-3(2H)-benzofuranone-5-carboxylic acids were synthetized and tested for antiallergic activity by the passive cutaneous anaphylactic reaction in the rat. Many compounds display an antiallergic activity comparable to that of disodium chromoglycate when administered parenterally: in addition some derivatives are effective when given by mouth.