(3-Oxo-1(3H)-isobenzofuranylidene)acetic acid 3-Carboxymethylenephthalide 3-Oxo-delta(sup 1,alpha)-phthalanacetic acid 4743-57-1 AI3-18620 Acetic acid, (3-oxo-1(3H)-isobenzofuranylidene)- (9CI) delta(sup 1,alpha)-Phthalanacetic acid, 3-oxo-