2-Chloro-N-(4-chlorobenzoyl)benzenesulfonamide toluene hemisolvate

The unit cell of the title compound, C13H9Cl2NO3S·0.5C7H8, contains two molecules of 2-chloro-N-(4-chlorobenzoyl)benzenesulfonamide and one toluene molecule, which is disordered about a centre of inversion. The dihedral angle between the two aromatic rings is 85.7 (1)°. In the crystal, molecules are linked by pairs of N—H⋯O(S) hydrogen bonds, forming centrosymmetric dimers.


Comment
In the present work, as a part of studying the effect of ring and the side chain substitutions on the crystal structures of N-aryl sulfonamides (Gowda et al., 2010a,b;Suchetan et al., 2010), the structure of 2-chloro-N-(4chlorobenzoyl)benzenesulfonamide (I) has been determined. The asymmetric unit of (I) contains also half a molecule of toluene which is disordered about a centre of inversion. The conformation of the N-C bond in the C-SO 2 -NH-C(O) segment has gauche torsions with respect to the SO bonds. In these segments, the N-H bond is anti to the C=O bond ( The molecule in (I) is twisted at the S atom with the C-SO 2 -NH-C(O) torsional angle of -62.7 (2)°, compared to those of -66.5 (2)° in (II), -62.6 (3)° and -62.6 (2)° in the two molecules of (III), and -53.1 (2)° and 61.2 (2)° in the two independent molecules of (IV).
The packing of molecules linked by N-H···O hydrogen bonds (Table 1) is shown in Fig. 2.

Experimental
The title compound was prepared by refluxing a mixture of 4-chlorobenzoic acid, 2-chlorobenzenesulfonamide and phosphorous oxychloride for 3 h on a water bath. The resultant mixture was cooled and poured into ice cold water. The solid obtained was filtered, washed thoroughly with water and then dissolved in sodium bicarbonate solution. The compound was later reprecipitated by acidifying the filtered solution with dilute HCl. It was filtered, dried and recrystallized.
Prism like colourless single crystals of the title compound used in X-ray diffraction studies were obtained by a slow evaporation of its toluene solution at room temperature.

Refinement
The H atom of the NH group was located in a difference map and later restrained to N-H = 0.86 (1) %A. The other H atoms were positioned with idealized geometry using a riding model with C-H = 0.93 Å. All H atoms were refined with isotropic supplementary materials sup-2 displacement parameters (set to 1.2 times of the U eq of the parent atom). The solvent toluene molecule is disordered about a centre of inversion. The components of the displacement parameters of C15 C16 C17 were restrained to be equal within an effective standard deviation 0.01. Fig. 1. Molecular structure of the title compound, showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level.    O2-S1-O1 118.68 (10) C18 i -C14-C14 i 106.8 (10)