N-(2,4-Dimethylphenyl)-2,4-dimethylbenzenesulfonamide

In the crystal structure of the title compound, C16H19NO2S, the molecule is bent at the S atom with a C—SO2—NH—C torsion angle of 66.5 (2)°. The dihedral angle between the sulfonyl and aniline benzene rings in the molecule is 41.0 (1)°. The crystal structure features inversion dimers linked by pairs of N—H⋯O hydrogen bonds.

In the crystal structure of the title compound, C 16 H 19 NO 2 S, the molecule is bent at the S atom with a C-SO 2 -NH-C torsion angle of 66.5 (2) . The dihedral angle between the sulfonyl and aniline benzene rings in the molecule is 41.0 (1) . The crystal structure features inversion dimers linked by pairs of N-HÁ Á ÁO hydrogen bonds.

Experimental
The solution of m-xylene (10 ml) in chloroform (40 ml) was treated dropwise with chlorosulfonic acid (25 ml) at 0° C. After the initial evolution of hydrogen chloride subsided, the reaction mixture was brought to room temperature and poured into crushed ice in a beaker. The chloroform layer was separated, washed with cold water and allowed to evaporate slowly. The residual 2,4-dimethylbenzenesulfonylchloride was treated with 2,4-dimethylaniline in the stoichiometric ratio and boiled for ten minutes. The reaction mixture was then cooled to room temperature and added to ice cold water (100 ml). The resultant solid 2,4-dimethyl-N-(2,4-dimethylphenyl)benzenesulfonamide was filtered under suction and washed thoroughly with cold water. It was then recrystallized to constant melting point from dilute ethanol. The purity of the compound was checked and characterized by recording its infrared and NMR spectra (Savitha & Gowda, 2006). Prism like brown single crystals used in X-ray diffraction studies were grown in ethanolic solution by slow evaporation at room temperature.

Refinement
The H atom of the NH group was located in a difference map and later restrained to N-H = 0.86 (2) Å. The other H atoms were positioned with idealized geometry using a riding model [C-H = 0.93-0.96 Å]. All H atoms were refined with isotropic displacement parameters (set to 1.2 times of the U eq of the parent atom).
supplementary materials sup-2 Figures Fig. 1. Molecular structure of (I), showing the atom-labelling scheme and displacement ellipsoids are drawn at the 50% probability level.

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.