Ethyl 6-(4-chlorophenyl)-4-(4-fluorophenyl)-2-oxocyclohex-3-ene-1-carboxylate

Abstract

The asymmetric unit of the title compound, C21H18ClFO3, contains two independent molecules. In one molecule (A), the 4-chlorophenyl, oxocyclohex-3-ene, carboxylate, and ethyl groups were refined as disordered over two sets of sites with a 0.684 (5):0.316 (5) ratio. The cyclohexene ring in the disordered molecule is in a slightly distorted envelope conformation for the major component (with the C atom bound to the carboxylate group being the flap atom) and in a screw-boat conformation for the minor component. In the ordered molecule (B), the cyclohexene ring is in a half-chair conformation. The dihedral angles between the mean planes of the fluoro- and chloro-substituted benzene rings are 89.9 (7) (only the major component is considered forA) and 76.4 (7)° (B). In the crystal, inversion dimers are observed along with weak C—H...O hydrogen bonds, which form chains along [100].