2-(2,3-Dimethylphenyl)-1H-isoindole-1,3(2H)-dione

In the title compound, C16H13NO2, the 2,3-dimethylphenyl group and the 1H-isoindole-1,3(2H)-dione group are essentially planar, with r.m.s. deviations of 0.006 and 0.013 Å, respectively, and are oriented at an angle of 78.19 (3)° with respect to each other. In the crystal, weak C—H⋯O interactions link the molecules, forming a zigzag chain parallel to the b axis. Futhermore, C—H⋯π interactions are present between the C—H group of isoindole and the 2,3-dimethylphenyl benzene ring. The H atoms of the ortho-methyl group are statistically disordered over two positions. Such disorder might be related to the antagonism between intramolecular steric repulsions and intermolecular C—H⋯O interactions.

In the title compound, C 16 H 13 NO 2 , the 2,3-dimethylphenyl group and the 1H-isoindole-1,3(2H)-dione group are essentially planar, with r.m.s. deviations of 0.006 and 0.013 Å , respectively, and are oriented at an angle of 78.19 (3) with respect to each other. In the crystal, weak C-HÁ Á ÁO interactions link the molecules, forming a zigzag chain parallel to the b axis. Futhermore, C-HÁ Á Á interactions are present between the C-H group of isoindole and the 2,3-dimethylphenyl benzene ring. The H atoms of the ortho-methyl group are statistically disordered over two positions. Such disorder might be related to the antagonism between intramolecular steric repulsions and intermolecular C-HÁ Á ÁO interactions.

Comment
We have reported crystal structures of Schiff bases containing 2,3-dimethylaniline ,  and . As part of our continuing interest in Schiff bases containing 2,3-dimethylaniline, we report here the structure of the title compound (I).
The H-atoms of the ortho-methyl group are statistically disordered over two positions. Such disorder might be related to the antagonism between intramolecular C-H···N and intermolecular C-H···O interactions ( Table 1). The weak C-H···O interactions links the molecule forming a non continuous zig-zag chain parallel to the b axis owing to the statistical distribution of the H atoms. Weak C-H···π interactions are also present (Table 1, where Cg2 is the centroid of the phenyl ring C1-C6).

Experimental
Equimolar quantities of 2,3-dimethylaniline and phthalic anhydride were refluxed in methanol for 48 h. The solution was kept at room temperature which affoarded white prism after 48 h.

Refinement
The H-atoms were positioned geometrically (C-H = 0.93-0.96 Å) and refined as riding with U iso (H) = xU eq (C), where x = 1.5 for methyl and x = 1.2 for aryl H-atoms.