Nimodipine EP Impurity A Catalogue N231531 CAS 85677-93-6 M.W 416.42 M.F C21H24N2O7 Specifications FAQs 3-isopropyl 5-(2-methoxyethyl) 2,6-dimethyl-4-(3-nitrophenyl)pyridine-3,5-dicarboxylate