Afatinib Impurity L Catalogue A155372 CAS 2223677-58-3 M.W 458.87 M.F C22H20ClFN4O4 Specifications FAQs 1-(4-((3-chloro-4-fluorophenyl)amino)-7-(((S)-tetrahydrofuran-3-yl)oxy)quinazolin-6-yl)-5-hydroxypyrrolidin-2-one