4-Chloro-N-(2,4-dimethylphenyl)-2-methylbenzenesulfonamide

In the title compound, C15H16ClNO2S, the C—SO2—NH—C torsion angle is 67.45 (17)°. The two aromatic rings are tilted relative to each other by 44.5 (1)°. The crystal structure features inversion-related dimers linked by pairs of N—H⋯O hydrogen bonds..

In the title compound, C 15 H 16 ClNO 2 S, the C-SO 2 -NH-C torsion angle is 67.45 (17) . The two aromatic rings are tilted relative to each other by 44.5 (1) . The crystal structure features inversion-related dimers linked by pairs of N-HÁ Á ÁO hydrogen bonds..
In (I), the N-H bond in the C-SO 2 -NH-C segment is syn with respect to the ortho-methyl group in the anilino benzene ring and orients towards the ortho-methyl group in the sulfonyl benzene ring. Further, the sulfonyl group orients itself away from the ortho-methyl groups in both the rings. The molecule is bent at the S atom with the C-SO 2 -NH-C torsion angle of 67.5 (2) The sulfonyl and the aniline benzene rings are tilted relative to each other by 44.5 (1)°, compared to the values of 44.1 (1)°i n molecule 1 and 39.7 (1)° in molecule 2 of (II), 86.6 (2)° and 83.0 (2)° in the two independent molecules of (III), and 76.6 (2)° in molecule 1 and 70.7 (2)° in molecule 2 of (IV).
The other bond parameters in (I) are similar to those observed in (II), (III) and other aryl sulfonamides (Perlovich et al., 2006;Gelbrich et al., 2007).
In the crystal, the intermolecular N-H···O hydrogen bonds (Table 1) link the molecules into dimeric chains. Part of the crystal structure is shown in Fig. 2.

Experimental
The solution of m-chlorotoluene (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-methyl-4-chlorobenzenesulfonylchloride 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 4-chloro-2-methyl-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).
Rod like light pink 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 refined with the N-H distance restrained to 0.86 (2) %A and U iso (H)= 1.2U eq (N). The other H atoms were positioned with idealized geometry using a riding model with aromatic C-H = 0.93Å and methyl C-H = 0.96 Å. Their displacement parameters were set to 1.2U eq (C aromatic ) or 1.5U eq (C methyl ). Fig. 1. Molecular structure of the title compound, showing the atom labelling scheme and displacement ellipsoids are drawn at the 50% probability level.