Amlodipine Impurity 20

Chemical Name: dimethyl 2,6-dimethyl-4-phenyl-1,4-dihydropyridine-3,5-dicarboxylate ; 1,4-Dihydro-2,6-dimethyl-4-phenyl-3,5-pyridinedicarboxylic Acid 3,5-Dimethyl Ester; 1,4-Dihydro-2,6-dimethyl-4-phenyl-3,5-pyridinedicarboxylic Acid Dimethyl Ester; 2,6-Dimethyl-3,5-bis(methoxycarbonyl)-4-phenyl-1,4-dihydropyridine