4-Chloro-2-methyl-N-(4-methylphenyl)benzenesulfonamide

The asymmetric unit of the title compound, C14H14ClNO2S, contains two independent molecules. The torsion angles of the C—SO2—NH—C segments in the two molecules are −76.5 (5) and −48.3 (4)°. The two aromatic rings are tilted relative to each other by 76.6 (2)° in one molecule and 70.7 (2)° in the other. In the crystal structure, intermolecular N—H⋯O hydrogen bonds link the molecules into centrosymmetric dimers.

The asymmetric unit of the title compound, C 14 H 14 ClNO 2 S, contains two independent molecules. The torsion angles of the C-SO 2 -NH-C segments in the two molecules are À76.5 (5) and À48.3 (4) . The two aromatic rings are tilted relative to each other by 76.6 (2) in one molecule and 70.7 (2) in the other. In the crystal structure, intermolecular N-HÁ Á ÁO hydrogen bonds link the molecules into centrosymmetric dimers.

Related literature
For the preparation of the title compound, see: Savitha & Gowda (2006). For our studies of the effect of substituents on the structures of N-(aryl)arylsulfonamides, see: Gowda et al. (2009Gowda et al. ( , 2010.

Comment
As part of a study of the substituent effects on the crystal structures of N-(aryl)arylsulfonamides (Gowda et al., 2009(Gowda et al., , 2010, in the present work, the structure of 4-chloro-2-methyl-N-(4-methylphenyl)benzenesulfonamide (I) has been determined ( Fig. 1). The asymmetric unit of (I) contains two independent molecules. In one of the molecules, the conformation of the N-C bond in the C-SO 2 -NH-C segment has gauche torsions with respect to the S═O bonds. The conformation of the N-H bonds are syn to the ortho-methyl groups in the sulfonyl benzene rings of both the molecules, similar to that observed in 4-chloro-2-methyl-N-(phenyl)benzenesulfonamide (II) (Gowda et al., 2009) and 4-chloro-2-methyl-N-(4chlorophenyl)benzenesulfonamide (III) (Gowda et al., 2010).
The sulfonyl and the aniline benzene rings in (I) are tilted relative to each other by 76.6 (2)° in molecule 1 and 70.7 (2)° in molecule 2, compared to the values of 86.6 (2)° and 83.0 (2)° in the two independent molecules of (II) and 67.0 (1)° in (III).
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 infinite zigzag row like 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 4-methylaniline 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 cc). The resultant solid 4-chloro-2-methyl-N-(4-methylphenyl)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 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 atoms were positioned with idealized geometry using a riding model [C-H = 0.93-0.96 Å] and were refined with isotropic displacement parameters (set to 1.2 times of the U eq of the parent atom).
The residual electron-density features are located in the region of O1 and S2. The highest peak is 0.77 Å from O1 and the deepest hole is 0.83 Å from S2. Fig. 1. The molecular structure of the title compound, showing the atom labelling scheme and displacement ellipsoids are drawn at the 50% probability level.  supplementary materials sup-9