4-Chloro-N-(3,5-dichlorophenyl)-2-methylbenzenesulfonamide

In the title compound, C13H10Cl3NO2S, torsion angle of the C—SO2—NH—C group in the molecule is −58.57 (26)°. The sulfonyl and aniline benzene rings are tilted relative to each other by 84.2 (1)°. The crystal structure features inversion-related dimers linked by pairs of N—H⋯O hydrogen bonds.

In the title compound, C 13 H 10 Cl 3 NO 2 S, torsion angle of the C-SO 2 -NH-C group in the molecule is À58.57 (26) . The sulfonyl and aniline benzene rings are tilted relative to each other by 84.2 (1) . The crystal structure features inversionrelated dimers linked by pairs of N-HÁ Á ÁO hydrogen bonds.
Data collection: CrysAlis CCD (Oxford Diffraction, 2009); cell refinement: CrysAlis RED (Oxford Diffraction, 2009); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97. In (I), the conformation of the N-C bond in the C-SO 2 -NH-C segment has trans and gauche torsion angles with the S═O bonds. Further, the N-H bond is syn to the ortho-methyl group in the sulfonyl benzene ring and to one of the meta-Cl atoms in the anilino ring of (I).
The molecule is bent at the S atom with the C-SO 2 -NH-C torsion angle of -58.57 (26)°, compared to the value of The sulfonyl and the aniline benzene rings are tilted relative to each other by 84.2 (1)°, compared to the value of 54.6 (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, 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 3,5-dichlorolaniline in the stoichiometric ratio 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 4-chloro-N-(3,5-dichlorophenyl)-2-methylbenzenesulfonamide 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 colourless 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 its coordinates were refined with the N-H distance restrained to 0.86 (2) %A. The other H atoms were positioned with idealized geometry using a riding model with the aromatic C-H = 0.93Å and methyl C-H = 0.96 Å. All H atoms were refined with isotropic displacement parameters U iso (H) set to 1.2U eq (C aromatic, N) and 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. 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 )
x y z U iso */U eq C1 0.6313 (