{1′-Phenyl-1′,2′,5′,6′,7′,7a’-hexahydrospiro[indeno[1,2-b]quinoxaline-11,3′-pyrrolizin]-2′-yl}(p-tolyl)methanone

In the title compound, C35H29N3O, the quinoxaline and indene systems are essentially planar, with maximum deviations of 0.047 (2) and 0.032 (2) Å for C atoms, respectively. The quinoxaline system forms a dihedral angle of 4.75 (3)° with the indene system. The pyrrolizine system is folded. The substituted five-membered ring adopts an envelope conformation. In the other five-membered ring, one C atom is disordered with a site-occupancy ratio of 0.676 (12):0.324 (12). In the crystal, molecules are linked via C—H⋯O hydrogen bonds involving the bifurcated carbonyl O atom.

In the title compound, C 35 H 29 N 3 O, the quinoxaline and indene systems are essentially planar, with maximum deviations of 0.047 (2) and 0.032 (2) Å for C atoms, respectively. The quinoxaline system forms a dihedral angle of 4.75 (3) with the indene system. The pyrrolizine system is folded. The substituted five-membered ring adopts an envelope conformation. In the other five-membered ring, one C atom is disordered with a site-occupancy ratio of 0.676 (12): 0.324 (12). In the crystal, molecules are linked via C-HÁ Á ÁO hydrogen bonds involving the bifurcated carbonyl O atom.
In the crystal packing, molecules are linked via bifurcated C-H···O intermolecular hydrogen bonds involving the carbonyl group O atom as a single acceptor (Table. 1). The packing view of the compound is shown in Fig. 2.

Experimental
A mixture of ninhydrin (1 mmol) and 1, 2-phenylenediamine (1 mmol) was stirred for 10 min in 10 mL of toluene followed by the addition of L-proline (1 mmol) and a solution of (E)-3-phenyl-1-p-tolylprop-2-en-1-one (1 mmol) in 10 ml of toluene. The mixture was then refluxed until completion of the reaction as evidenced by TLC. The solvent was removed in vacuo and the crude product was subjected to column chromatography using petroleum ether/ethyl acetate (4:1) as eluent.

Refinement
Hydrogen atoms were placed in calculated positions with C-H = 0.93 Å to 0.98 Å and refined using a riding model with fixed isotropic displacement parameters:U iso (H) = 1.5U eq (C) for methyl group and U iso (H) = 1.2U eq (C) for other groups.
The distances between the disordered atoms and its neighbours were restrained to be equal with an effective e.s.d. of

Figure 1
The molecular structure of the title compound, showing displacement ellipsoids drawn at the 30% probability level. H atoms are presented as a small spheres of arbitrary radius.

Data collection
Bruker SMART APEXII area-detector diffractometer Radiation source: fine-focus sealed tube Graphite monochromator ω and φ scans 47718 measured reflections 6643 independent reflections 3751 reflections with I > 2σ(I) Special details Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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.