Erlotinib Impurity B Catalogue E212202 CAS 183320-04-9 (free base:183321-83-7) M.W 434.32 M.F C21H20ClN3O3.HCl Specifications FAQs 6-(2-chloroethoxy)-N-(3-ethynylphenyl)-7-(2-methoxyethoxy)quinazolin-4-amine hydrochloride