4-(4-Bromophenyl)-8-methyl-2-oxo-1,2,3,4,4a,5,6,7-octahydroquinoline-3-carbonitrile

In the title compound, C17H17BrN2O, the N-containing ring adopts an envelope conformation with the C atom carrying the phenyl ring displaced by −0.531 (9) Å from the plane defined by the remaining five atoms (r.m.s. deviation = 0.0099 Å). The benzene ring is almost orthogonal to the ring to which it is attached, the CCN—C—CPh—CPh torsion angle being −101.3 (7)°. The cyclohexene ring is disordered over two conformations in a statistical ratio. The most prominent interactions in the crystal are pairs of N—H⋯O hydrogen bonds between inversion-related molecules. The resulting dimers are linked into a three-dimensional architecture by C—H⋯N, C—H⋯Br and C—H⋯π interactions.

In the title compound, C 17 H 17 BrN 2 O, the N-containing ring adopts an envelope conformation with the C atom carrying the phenyl ring displaced by À0.531 (9) Å from the plane defined by the remaining five atoms (r.m.s. deviation = 0.0099 Å ). The benzene ring is almost orthogonal to the ring to which it is attached, the C CN -C-C Ph -C Ph torsion angle being À101.3 (7) . The cyclohexene ring is disordered over two conformations in a statistical ratio. The most prominent interactions in the crystal are pairs of N-HÁ Á ÁO hydrogen bonds between inversion-related molecules. The resulting dimers are linked into a three-dimensional architecture by C-HÁ Á ÁN, C-HÁ Á ÁBr and C-HÁ Á Á interactions.
The most prominent interactions in the crystal packing is a pair of N-H···O hydrogen bonds between inversion related molecules leading to an eight-membered {···HNCO} 2 synthon, Table 1. These are linked into a three-dimensional architecture by C-H···N, C-H···Br and C-H···π interactions, Fig. 2 and Table 1.

Refinement
Carbon-bound H-atoms were placed in calculated positions [C-H = 0.95-0.99 Å, U iso (H) = 1.2-1.5U eq (C)] and were included in the refinement in the riding model approximation. The N-bound H-atom was treated similarly with N-H = 0.88 Å and with U iso (H) = 1.2U eq (N). A part of the cyclohexene ring is disordered over two positions in an assumed 1:1 ratio. Pairs of 1,2-related distances were restrained to within 0.01 Å of each other. The anisotropic displacement parameters, restrained to be nearly isotropic, of the primed atoms were set to those of the unprimed ones. The amino Hatom is less than 2 Å from a methyl H-atom. As the methyl group was refined as a disordered methyl group, the short  (Farrugia, 1997) and DIAMOND (Brandenburg, 2006); software used to prepare material for publication: publCIF (Westrip, 2010).

Special details
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq Occ. (