(+/-)-Methyl and (+/-)-ethyl 4-(2,3-difluorophenyl)-2,6,6-trimethyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate.

The title compounds, C20H21F2NO3 and C21H23F2NO3, respectively, belong to a class of 1,4-dihydropyridines whose members sometimes display calcium modulatory properties. The 1,4-dihydropyridine rings have the usual shallow boat conformation. In each structure, the 2,3-difluorophenyl ring is oriented such that the fluoro substituents are in a synperiplanar orientation with respect to the 1,4-dihydropyridine ring plane and the oxocyclohexene ring has a slightly distorted envelope conformation. Both structures exhibit the same intermolecular N-H...O hydrogen-bonding motif, in which the molecules are linked into chains by interactions involving the carbonyl O atom of the oxocyclohexene ring.