Diethyl 4-(4-acetamidophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate

The title compound, C21H26N2O5, was unexpectedly obtained as a by-product in the reaction of ethyl acetoacetate, 4-acetamidobenzaldehyde and urea under microwave irradiation. The dihydropyridine ring assumes a flattened boat conformation. Intermolecular N—H...O and weak C—H...O hydrogen bonding occurs in the crystal.