Afatinib Impurity G Catalogue A155367 M.W 485.94 M.F C24H25ClFN5O3 Specifications FAQs (S,E)-N-(4-((4-chloro-3-fluorophenyl)amino)-7-((tetrahydrofuran-3-yl)oxy)quinazolin-6-yl)-4-(dimethylamino)but-2-enamide