1-Allyl-3,3-di-p-tolylindolin-2-one

In the title compound, C25H23NO, the indoline system is essentially planar. The molecular structure is stabilized by weak intramolecular C—H⋯N interactions and the crystal packing is determined by intermolecular C—H⋯π interactions.

In the title compound, C 25 H 23 NO, the indoline system is essentially planar. The molecular structure is stabilized by weak intramolecular C-HÁ Á ÁN interactions and the crystal packing is determined by intermolecular C-HÁ Á Á interactions.

S1. Comment
Indole compounds can be used as bioactive drugs (Stevenson et al., 2000). Indole derivatives exhibit anti-allergic, central nervous system depressant and muscle relaxant properties (Harris & Uhle, 1960;Ho et al., 1986). Indoles have also been proved to display high aldose reductase inhibitory activity (Rajeswaran et al., 1999). In view of this biological importance, an X-ray study of the title compound, (I), was carried out.

S2. Experimental
To a solution of p-methyl phenyl magnesium bromide in dry THF, at 0°C under N 2 atm.,1-N-allyl isatin (0.0125 mol, 2.34 g), in dry THF, was added dropwise. After the complete addition, the mixture was stirred at 0°C for 1 hr and then it was stirred at room temperature for 5 hrs. On completion of the reaction, a saturated solution of NH 4 Cl was added slowly at 0°C. The aqueous layer was extracted with ether, and the combined organic layer was extracted with ether. The crude mass was obtained., which was purified over a column of silica gel using hexane/ethyl acetate as eluent. Compound was recrystallized from methanol.

S3. Refinement
H atoms were positioned geometrically and were treated as riding on their parent C atoms, with aromatic C-H distances of 0.93 Å, methyl C-H distances of 0.96 Å and methylene C-H distances of 0.97 Å, and with U iso (H) = 1.5U eq (C) for methyl H and 1.2U eq (C) for other H atoms.  The molecular structure of (I) with 30% probability displacement ellipsoids supporting information

Figure 2
The packing of the molecules viewed down b axis.

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.