N-(2,4-Dimethylphenyl)succinimide

In the title compound, C12H13NO2, the dihedral angle between the benzene ring and the imide segment is 85.7 (1)°. In the crystal, the molecules are packed into zigzag chains parallel to the a axis.

In the title compound, C 12 H 13 NO 2 , the dihedral angle between the benzene ring and the imide segment is 85.7 (1) . In the crystal, the molecules are packed into zigzag chains parallel to the a axis.  BSS thanks the University Grants Commission, Government of India, New Delhi, for the award of a research fellowship under its faculty improvement program.

Comment
As a part of studying the effect of ring and side chain substitutions on the structures of biologically significant compounds (Gowda et al., 2007;Saraswathi et al., 2010a,b), the crystal structure of N, N-(2,4-dimethylphenyl)succinimide has been determined ( Fig. 1). The dihedral angle between the benzene ring and the imide segment in the molecule is 85.7 (1)°.
The packing of molecules into zigzag chains is shown in Fig.2.

Experimental
The solution of succinic anhydride (0.025 mole) in toluene (25 ml) was treated dropwise with the solution of 2,4-dimethylaniline (0.025 mole) also in toluene (20 ml) with constant stirring. The resulting mixture was stirred for one h and set aside for an additional hour at room temperature for the completion of reaction. The mixture was then treated with dilute hydrochloric acid to remove the unreacted 2,4-dimethylaniline. The resultant solid N-(2,4-dimethylphenyl)succinamic acid was filtered under suction and washed thoroughly with water to remove the unreacted succinic anhydride and succinic acid. It was recrystallized to constant melting point from ethanol.
N-(2,4-Dimethylphenyl)succinamic acid was heated for 2 h and then allowed to cool slowly to room temperature to get the compound, N-(2,4-dimethylphenyl)succinimide. The purity of the compound was checked and characterized by its infrared spectra.
The rod like colourless single crystals of the compound used in X-ray diffraction studies were grown in ethanolic solution by a slow evaporation at room temperature.

Refinement
The H atoms of the CH 3 groups were positioned with idealized geometry using a riding model with C-H = 0.96 Å. The other H atoms were located in a difference map and their position refined to C-H = 0.91 (3)-1.06 (3) Å. All H atoms were refined with isotropic displacement parameters (set to 1.2 times of the U eq of the parent atom).
In the absence of significant anomalous dispersion effects, Friedel pairs were merged and the Δf"term set to zero.

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 > σ(F 2 ) is used only for calculating Rfactors(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.