4-Chloro-N-(4-chlorobenzoyl)benzenesulfonamide

In the title compound, C13H9Cl2NO3S, the conformation of the N—H bond in the C—SO2—NH—C(O) segment is anti to the C=O bond. The molecule is twisted at the S atom with a torsion angle of 67.5 (3)°. The dihedral angle between the sulfonyl benzene ring and the —SO2—NH—C—O segment is 79.0 (1)° and that between the sulfonyl and benzoyl benzene rings is 85.6 (1)°. In the crystal, molecules are linked by N—H⋯O(S) hydrogen bonds with graph-set descriptor C(4) along the [010] direction.

In the title compound, C 13 H 9 Cl 2 NO 3 S, the conformation of the N-H bond in the C-SO 2 -NH-C(O) segment is anti to the C O bond. The molecule is twisted at the S atom with a torsion angle of 67.5 (3) . The dihedral angle between the sulfonyl benzene ring and the -SO 2 -NH-C-O segment is 79.0 (1) and that between the sulfonyl and benzoyl benzene rings is 85.6 (1) . In the crystal, molecules are linked by N-HÁ Á ÁO(S) hydrogen bonds with graph-set descriptor C(4) along the [010] direction.

D-HÁ
The molecules are linked by of N-H···O(S) hydrogen bonds with graph-set descriptor C (4)

Experimental
The title compound was prepared by refluxing a mixture of 4-chlorobenzoic acid, 4-chlorobenzenesulfonamide and phosphorous oxy chloride 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 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)
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
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.