N-(2,3-Dimethylphenyl)-2,4-dimethylbenzenesulfonamide

The asymmetric unit of the title compound, C16H19NO2S, contains two independent molecules: the dihedral angles between the sulfonyl and anilino benzene rings in the two molecules are 41.5 (1) and 43.8 (1)°. The independent molecules are linked into a dimer by a pair of intermolecular N—H⋯O hydrogen bonds.

The asymmetric unit of the title compound, C 16 H 19 NO 2 S, contains two independent molecules: the dihedral angles between the sulfonyl and anilino benzene rings in the two molecules are 41.5 (1) and 43.8 (1) . The independent molecules are linked into a dimer by a pair of intermolecular N-HÁ Á ÁO hydrogen bonds.
In the crystal structure, pairs of intermolecular N-H···O hydrogen bonds (Table 1) link the independent molecules to form dimers as shown in Fig. 1 and Fig.2.

Experimental
The solution of m-xylene (10 ml) in chloroform (40 ml) was treated dropwise with chlorosulfonic acid (25 ml) at 273 K.
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 a stoichiometric amount of 2,3-dimethylaniline and boiled for 10 min. The reaction mixture was then cooled to room temperature and added to ice cold water (100 ml). The resultant solid 2,4-dimethyl-N-(2,3-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). The single crystals used in X-ray diffraction studies were grown in ethanolic solution by slow evaporation at room temperature.

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.
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )