Amlodipine Acetyl Impurity

3-Ethyl 5-Methyl 2-((2-acetamidoethoxy)methyl)-4-(2-chlorophenyl)-6-methyl-1,4-dihydropyridine-3,5-
dicarboxylate; 3,5-Dicarboxylate, 3-Ethyl 5-Methyl 2-((2-acetamidoethoxy)methyl)-4-(2-chlorophenyl)-6-methyl-1,4-dihydropyridine-;