N-Ethyl-3-buteno-o-toluidide;N-Ethyl-N-(2-methylphenyl)but-3-enamide;Crotamiton EP Impurity A;3-Butenamide, N-ethyl-N-(2-methylphenyl)-;Crotamiton Impurity 13;Crotamiton impurity I;N-Ethyl-N-(o-tolyl)but-3-enamide (Crotamiton Impurity);Cromilton EP Impurity A