Oxanilic acids, a new series of orally active antiallergic agents

A large number of oxanilic acid esters and N-heteroaryl oxamic acid esters were prepared and found to have antiallergic activity using the rat passive cutaneous anaphylaxis (PCA) test. Many of the oxanilic acid esters are active orally, with the most active species having an aryl 2'-carbamoyl group and a 3'-methoxy group. Hydrolysis of the ester from the oxanilic ester moiety causes a loss of oral activity.