Abstract
The six-membered N-heterocyclic ring of title compound, C17H17ClN2O, is fused with a methyl-substituted cyclohexene ring. The nitrogen-bearing ring has an envelope conformation with the benzene ring-bearing C atom lying 0.432 (6) angstrom out of the plane defined by the other five atoms (r.m.s. deviation 0.011 angstrom); its benzene substituent is aligned at 84.7 (1)degrees to the latter plane. The cyclohexene ring adopts a half-chair conformation. In the crystal, two molecules are linked about a center of inversion by pairs of N-H center dot center dot center dot O hydrogen bonds, generating dimers. An ethylene portion is disordered over two orientations in a 1:1 ratio. The crystal studied was a non-merohedral twin with a 15.3 (1)% minor component.