4-(4-Chloro-phen-yl)-8-methyl-2-oxo-1,2,5,6,7,8-hexa-hydro-quinoline-3-carbonitrile.

The six-membered N-heterocyclic ring of the title compound, C(17)H(15)ClN(2)O, is fused with a methyl-substituted cyclo-hexene ring. The approximately planar nitro-gen-bearing ring (r.m.s. deviation 0.019 Å) is aromatic, and the N atom shows a trigonal-planar coordination; its benzene substituent is aligned at 77.1 (1) °. The cyclo-hexene ring adopts a half-chair conformation. In the crystal, inversion-related mol-ecules are linked by pairs of N-H⋯O hydrogen bonds, generating dimers.