Erlotinib Impurity N Catalogue E212214 CAS 183321-86-0 (HCL:183320-51-6) M.W 379.42 M.F C21H21N3O4 Specifications FAQs 2-((4-((3-ethynylphenyl)amino)-7-(2-methoxyethoxy)quinazolin-6-yl)oxy)ethan-1-ol