N-(2,5-Dichlorophenyl)-4-methylbenzenesulfonamide

In the title compound, C13H11Cl2NO2S, the N—C bond in the C—SO2—NH—C segment has gauche torsion angles with respect to the S=O bonds. The molecule is bent at the S atom with an C—SO2—NH—C torsion angle of 62.1 (2)°. Furthermore, the conformation of the N—H bond is syn to the ortho-chloro group in the adjacent benzene ring. The benzene rings are tilted by 67.8 (1)° relative to each other. The crystal structure features dimers linked by N—H⋯O hydrogen bonds. An intramolecular N—H⋯Cl hydrogen bond is also observed.

In the title compound, C 13 H 11 Cl 2 NO 2 S, the N-C bond in the C-SO 2 -NH-C segment has gauche torsion angles with respect to the S O bonds. The molecule is bent at the S atom with an C-SO 2 -NH-C torsion angle of 62.1 (2) . Furthermore, the conformation of the N-H bond is syn to the orthochloro group in the adjacent benzene ring. The benzene rings are tilted by 67.8 (1) relative to each other. The crystal structure features dimers linked by N-HÁ Á ÁO hydrogen bonds. An intramolecular N-HÁ Á ÁCl hydrogen bond is also observed.
An intramolecular N-H···Cl hydrogen bond is observed. The crystal packing of molecules in (I) via N-H···O(S) hydrogen bonds (Table 1) is shown in Fig. 2.

Experimental
The solution of toluene (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 4-methylbenzenesulfonylchloride was treated with 2,5-dichloroaniline 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 4-methyl-N-(2,5-dichlorophenyl)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.
The prism like light brown single crystals used in X-ray diffraction studies were grown in ethanolic solution by slow evaporation at room temperature.