N-(2-Chlorophenyl)-4-methylbenzenesulfonamide

The molecule of the title compound, C13H12ClNO2S, is bent at the S atom with a C—SO2—NH—C torsion angle of −54.8 (2)°. The dihedral angle between the two aromatic rings is 71.6 (1)°. An intramolecular N—H⋯Cl hydrogen bond is observed. The crystal structure features inversion-related dimers formed by pairs of N—H⋯O hydrogen bonds.


Comment
As part of a study of the effect of substituents on crystal structures of N-(aryl)-arylsulfonamides (Gowda et al., 2009;Nirmala et al., 2009), the crystal structure of N-(2-chlorophenyl)4-methylbenzenesulfonamide (I) has been determined. The conformation of the N-H bond is syn to the 2-chloro group in the aniline benzene ring. The molecule is bent at the S atom with a C1-S1-N1-C7 torsion angle of -54.8 (2)°, compared to the value of -51.6 (3)° in N-(phenyl)4-methylbenzenesulfonam- The two benzene rings in (I) are tilted relative to each other by 71.6 (1)°, compared to 68.4 (1)° in (II) and 49.7 (1)°i n (III). The other bond parameters are similar to those observed in (II), (III) and other aryl sulfonamides (Perlovich et al., 2006;Gelbrich et al., 2007).
The structure exhibits both the intramolecular N-H···Cl and the intermolecular N-H···O(S) hydrogen bonds.
In the crystal structure, pairs of intermolecular N-H···O hydrogen bonds (Table 1) link the molecules into inversion-related dimers. Part of the crystal structure is shown in Fig. 2.

Experimental
A solution of toluene (10 ml) in chloroform (40 ml) was treated dropwise with chlorosulfonic acid (25 ml) at 273 K. 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 benzenesulfonylchloride was treated with 2-chloroaniline 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-methyl-N-(2-chlorophenyl)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 IR and NMR spectra. Single crystals used in X-ray diffraction studies were grown by a slow evaporation of an ethanolic solution at room temperature.

Refinement
The H atom of the NH group was located in a difference map and its positional parameters were refined [N-H = 0.83 (3) Å]. The other atoms were positioned with idealized geometry using a riding model [C-H = 0.93-0.96 Å]. All H atoms were refined with isotropic displacement parameters (set to 1.2 times of the U eq of the parent atom).   as those based on F, and R-factors based on ALL data will be even larger.