1′,1′′-Dimethyl-4′-(naphthalen-1-yl)-1,2,3,4-tetrahydronaphthalene-2-spiro-3′-pyrrolidine-2′-spiro-3′′-indoline-1,2′′-dione

In the title compound, C32H28N2O2, the pyrrolidine ring adopts an envelope conformation, whereas the cyclohexanone ring in the tetrahydronaphthalene fused-ring system adopts a half-chair conformation. The oxindole ring system is oriented at an angle of 48.2 (1)° with respect to the naphthyl ring system. An intramolecular C—H⋯O close contact is observed. In the crystal, molecules associate via two C—H⋯O hydrogen bonds, forming R 2 2(14) and R 2 2(10) dimers.

In the title compound, C 32 H 28 N 2 O 2 , the pyrrolidine ring adopts an envelope conformation, whereas the cyclohexanone ring in the tetrahydronaphthalene fused-ring system adopts a half-chair conformation. The oxindole ring system is oriented at an angle of 48.2 (1) with respect to the naphthyl ring system. An intramolecular C-HÁ Á ÁO close contact is observed. In the crystal, molecules associate via two C-HÁ Á ÁO hydrogen bonds, forming R 2 2 (14) and R 2 2 (10) dimers. Experimental Crystal data
These derivatives possess anticonvulsant (Kaminski & Obniska, 2008) and anti-influenza virus (Stylianakis et al., 2003) activities. In view of these importance and continuation of our work on the crystal structure analyis of spiro-pyrrolidine derivatives, we have undertaken the crystal structure determination of the title compound, and the results are presented here.
The X-ray study confirmed the molecular structure and atomic connectivity for (I), as illustrated in Fig. 1. The geometry of pyrrolidine, tetrahydro naphthalin and naphthyl group systems are comparable with the related reported structure (Selvanayagam et al., 2011). Fig. 2 shows a superposition of the pyrrolidine ring of (I) with this related reported structure, Pyrrolidine ring is in an envelope conformation, with puckering parameters q 2 = 0.409 (1) Å and φ = -175.1 (2) °, and with atom N1 deviating -0.603 (2) Å from the least-squares plane passing through the remaining four atoms (C1-C4) of that ring (Cremer & Pople, 1975). The cyclohexanone ring in the tetrahydro naphthalin ring system has a half-chair conformation with the lowest asymmetry parameters of ΔC 2 (C2-C12) = 0.084 (1)° (Nardelli, 1983). The best plane of pyrrolidine ring system make a dihedral angles of 76.9 (1) and 68.9 (1)°, respectively with respect to the oxindole ring and naphtyl group systems.
The molecular structure is influenced by an intramolecular C-H···O close contacts. Atom O1 acts as a trifurcated acceptor for three intramolecular C-H···O contacts. In the molecular packing, C-H···O hydrogen bonds involving atoms C13 and O1 link inversion-related molecules to form R 2 2 (14) graph-set dimer ( Fig. 3 and Table 1). In addition to this another graph-set dimer of R 2 2 (10) forms in the unit cell involving C32 and O1 atoms via C-H···O hydrogen bonds (Fig. 4).

Experimental
To a mixture of N-methyl isatin (1mmol), sarcosine (1mmol) and 2-napthalidene-1,2,3,4-tetrahydronaphthalene-1-ones (1mmol) was added and heated under reflux in methanol (20ml) until the disappearance of the starting materials as evidenced by TLC. The solvent was removed under vacuo. The crude product was subjected to column chromatography using petroleum ether-ethyl acetate as eluent. Single crystals were grown by slow evaporation from methanol.
supplementary materials sup-2 Refinement H atoms were placed in idealized positions and allowed to ride on their parent atoms, with C-H distances of 0.93-0.97 Å, and Uiso(H) = 1.5U eq (C) for methyl H and Uiso(H) = 1.2U eq (C) for all other H atoms.

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.
supplementary materials sup-4 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.