1′-Methyl-4′-(4-methylphenyl)dispiro[1-benzopyran-3(4H),3′-pyrrolidine-2′,3′′-indoline]-2,2′′-dione

In the title compound, C27H24N2O3, the pyrroldine ring adopts a twist conformation, while the six-membered pyranone ring of the coumarin ring system is in a sofa conformation. In the crystal, pairs of N—H⋯O hydrogen bonds link the molecules into inversion R 2 2(8) dimers. These dimers are further connected via C—H⋯O hydrogen bonds.

In the title compound, C 27 H 24 N 2 O 3 , the pyrroldine ring adopts a twist conformation, while the six-membered pyranone ring of the coumarin ring system is in a sofa conformation. In the crystal, pairs of N-HÁ Á ÁO hydrogen bonds link the molecules into inversion R 2 2 (8) dimers. These dimers are further connected via C-HÁ Á ÁO hydrogen bonds.

Comment
Highly functionalized pyrrolidines have gained much interest in the past few years as they constitute the main structural element of many natural and synthetic pharmacologically active compounds (Waldmann, 1995). Optically active pyrrolidines have been used as intermediates, chiral ligands or auxiliaries in controlled asymmetric synthesis (Suzuki et al., 1994;Huryn et al., 1991). In view of this importance, the crystal structure of the title compound has been carried out and the results are presented here.
The title compound consists of a pyrrolidine ring connected to a oxindole ring system at C1, a coumarine moiety at C2 and a benzene ring at C3. The X-ray analysis confirms the molecular structure and atom connectivity as illustrated in Fig.1.

Experimental
A mixture of E-3-(4-methylbenzylidene)chroman-2-one (0.125 g, 0.5 mmol), isatin (0.08 g, 0.55 mmol) and N-methylglycine (0.025 g, 0.55 mmol) in toluene (5 ml) as solvent was allowed to reflux for 6 hours. After work up, the crude mass was purified by column chromatography to yield the pure product (0.195 g, 92% yield). The compound was recrystallized from ethyl acetate solvent. Single crystals suitable for X-ray diffraction were obtained by slow evaporation of a ethylacetate solution at room temperature.
supplementary materials sup-2 Refinement H atoms were positioned geometrically, with N-H = 0.86 Å and and C-H = 0.93-0.98 Å and constrained to ride on their parent atom, with U iso (H)=1.5U eq for methyl H atoms and 1.2U eq (C) for other H atoms. Fig. 1. The molecular structure of the title compound with the atom numbering scheme. Displacement ellipsoids are drawn at the 30% probability level. H atoms are presented as a small cycles of arbitrary radius.

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.