N-(2-Chlorobenzoyl)-2-nitrobenzenesulfonamide

In the title compound, C13H9ClN2O5S, the dihedral angle between the two rings is 71.2 (1)°. The crystal structure features inversion dimers linked by pairs of N—H⋯O(S) hydrogen bonds.

In the title compound, C 13 H 9 ClN 2 O 5 S, the dihedral angle between the two rings is 71.2 (1) . The crystal structure features inversion dimers linked by pairs of N-HÁ Á ÁO(S) hydrogen bonds.
BTG thanks the University Grants Commission, Government of India, New Delhi, for a special grant under the UGC-BSR one-time grant to faculty. P. A. Suchetan, S. Foro and B. T. Gowda
The conformation between the N-H and C=O bonds in the C-SO 2 -NH-C(O) segment is anti and the N-C bond in the segment has gauche torsion with respect to the S═O bonds ( Fig.1), similar to that observed in N-(3-chlorobenzoyl)-3-nitrobenzenesulfonamide (II) (Suchetan et al., 2012). In (I), the conformation between the N-H bond and the ortho-nitro group in the sulfonyl benzene ring is syn, similar to that observed between the N-H bond and the meta-nitro group in (II).
Further, the conformation of the C═O is anti to the ortho-Cl atom in the benzoyl ring, similar to that observed between the C═O and the meta-Cl atom in (II).
The molecule is twisted at the S-N bond with the torsional angle of -59.68 (17)°, compared to the value of -60.40 (29)°i n (II).
The dihedral angle between the sulfonyl benzene ring and the -SO 2 -NH-C-O segment is 77.5 (1)°, compared to the value of 77.0 (1)° in (II). Furthermore, the dihedral angle between the sulfonyl and the benzoyl benzene rings is 71.2 (1)°, compared to the value of 83.5 (1)° in (II).
In the crystal, the intermolecular N-H···O (S) hydrogen bonds (Table 1) link the molecules into centrosymmetric dimers.
Part of the crystal structure is shown in Fig. 2.

Experimental
The title compound was prepared by refluxing a mixture of 2-chlorobenzoic acid (0.02 mole), 2-nitrobenzenesulfonamide (0.02 mole) and excess phosphorous oxychloride for 3 h on a water bath. The resultant mixture was cooled and poured into crushed ice. The solid, N-(2-chlorobenzoyl)-2-nitrobenzenesulfonamide, obtained was filtered, washed thoroughly with water and then dissolved in a 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 slow evaporation of its toluene solution at room temperature.