11-(4-Methylphenyl)-8,9-dihydro-7H-benzo[f]cyclopenta[b]quinolin-10(11H)-one

In the title compound, C23H19NO, the naphthalene ring system and the cyclopent-2-enone ring exhibit planar conformations with maximum deviations of 0.034 (1) and 0.02 (1) Å, respectively. The 1,4-dihydropyridine ring adopts an envelope conformation with the C atom bearing the p-tolyl ring as the flap atom. Intermolecular N—H⋯O hydrogen bonds and C—H⋯π interactions stabilize the crystal packing.

In the title compound, C 23 H 19 NO, the naphthalene ring system and the cyclopent-2-enone ring exhibit planar conformations with maximum deviations of 0.034 (1) and 0.02 (1) Å , respectively. The 1,4-dihydropyridine ring adopts an envelope conformation with the C atom bearing the p-tolyl ring as the flap atom. Intermolecular N-HÁ Á ÁO hydrogen bonds and C-HÁ Á Á interactions stabilize the crystal packing. H atoms treated by a mixture of independent and constrained refinement Á max = 0.36 e Å À3 Á min = À0.32 e Å À3 Table 1 Hydrogen-bond geometry (Å , ).

Related literature
Cg1 is the centroid of the C17-C22 ring.  [b]quinolins, the title compound (I) was isolated and its structure was determined by X-ray diffraction.

D-HÁ
Herein we report its crystal structure.

Refinement
The hydrogen atom bonded to nitrogen atom was positioned from a Fourier difference map refined freely. All other H atoms were placed in calculated positions, with C-H = 0.95 Å, 0.98 Å, 0.99 Å or 1.00 Å and included in the final cycles of refinement using a riding model, with U iso (H) = 1.2U eq (parent atom).  The structure of (I), showing 30% probability displacement ellipsoids and the atom-numbering scheme.  The packing diagram of (I), Hydrogen bond represented by the dashed line, Cg is the centroid of the ring of C17/C18/C19/C20/C21/C22, Hydrogen atoms not involved in Hydrogen bond were omitted for clarity.

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.