(S,E)-N-(4-((3,4-Difluorophenyl)amino)-7-((tetrahydrofuran-3-yl)oxy)quinazolin-6-yl)-4-(dimethylamino)but-2-enamide (Afatinib Impurity)

(S,E)-N-(4-((3,4-Difluorophenyl)amino)-7-((tetrahydrofuran-3-yl)oxy)quinazolin-6-yl)-4-(dimethylamino)but-2-enamide (Afatinib Impurity)