2,4-Dichloro-N-(3,5-dimethylphenyl)benzenesulfonamide

In the crystal of the title compound, C14H13Cl2NO2S, the N—H bond in the C—SO2—NH—C segment is syn to one of the meta-methyl groups in the aniline benzene ring and anti to the other. Further, the conformation of the N—C bond in the C—SO2—NH—C segment is gauche with respect to the S=O bonds. The C—SO2—NH—C torsion angle is 54.9 (2)°. The sulfonyl and aniline benzene rings are tilted relative to each other by 82.8 (1)°. The crystal structure features inversion-related dimers linked by pairs of N—H⋯O hydrogen bonds. There are also weak C—H⋯O hydrogen bonds between these dimers.

In the crystal of the title compound, C 14 H 13 Cl 2 NO 2 S, the N-H bond in the C-SO 2 -NH-C segment is syn to one of the meta-methyl groups in the aniline benzene ring and anti to the other. Further, the conformation of the N-C bond in the C-SO 2 -NH-C segment is gauche with respect to the S O bonds. The C-SO 2 -NH-C torsion angle is 54.9 (2) . The sulfonyl and aniline benzene rings are tilted relative to each other by 82.8 (1) . The crystal structure features inversionrelated dimers linked by pairs of N-HÁ Á ÁO hydrogen bonds. There are also weak C-HÁ Á ÁO hydrogen bonds between these dimers.
VZR thanks the University Grants Commission, Government of India, New Delhi, for the award of an RFSMS fellowship.
In (I), the N-H bond in the C-SO 2 -NH-C segment is syn to one of the meta-methyl groups in the aniline benzene ring and anti to the other. Further, the conformations of the N-C bonds in the C-SO 2 -NH-C segment have gauche torsions with respect to the S═O bonds.
The sulfonyl and the aniline benzene rings are tilted relative to each other by 66.4 (1)°, compared to the value of 82.8 (1)°i n (II) The other bond parameters in (I) are similar to those observed in (II) and other aryl sulfonamides (Perlovich et al., 2006;Gelbrich et al., 2007).
In the crystal structure, the pairs of intermolecular N-H···O hydrogen bonds (Table 1) link the molecules into inversionrelated dimers. There is also weak C-H···O hydrogen bonds between these dimers. Part of the crystal structure is shown in Fig. 2.

Experimental
The solution of 1,3-dichlorobenzene (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-dichlorobenzenesulfonylchloride was treated with 3,5-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-dichloro-N-(3,5-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 light pink single crystals used in X-ray diffraction studies were grown in ethanolic solution by slow evaporation at room temperature.