Ethyl 6-(4-chloro-phen-yl)-4-(4-fluoro-phen-yl)-2-oxo-cyclo-hex-3-ene-1-carboxyl-ate

The asymmetric unit of the title compound, C21H18ClFO3, contains two independent mol-ecules. In one mol-ecule (A), the 4-chloro-phenyl, oxo-cyclo-hex-3-ene, carboxyl-ate, and ethyl groups were refined as disordered over two sets of sites with a 0.684 (5):0.316 (5) ratio. The cyclo-hexene ring in the disordered mol-ecule 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 mol-ecule (B), the cyclo-hexene 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 for A) 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].