4-Chloro-N-(3-methylbenzoyl)benzenesulfonamide monohydrate

In the title compound, C14H12ClNO3S·H2O, the dihedral angle between the sulfonyl and benzoyl benzene rings is 84.4 (2)°. In the crystal, every water molecule forms four hydrogen bonds with three different molecules of 4-chloro-N-(3-methylbenzoyl)benzenesulfonamide. One of the water H atoms forms a bifurcated hydrogen bond with both the sulfonyl and the carbonyl O atoms of the same molecule. Molecules are linked into layers in the ab plane through N—H⋯O and O—H⋯O hydrogen bonds.

In the title compound, C 14 H 12 ClNO 3 SÁH 2 O, the dihedral angle between the sulfonyl and benzoyl benzene rings is 84.4 (2) . In the crystal, every water molecule forms four hydrogen bonds with three different molecules of 4-chloro-N-(3-methylbenzoyl)benzenesulfonamide. One of the water H atoms forms a bifurcated hydrogen bond with both the sulfonyl and the carbonyl O atoms of the same molecule. Molecules are linked into layers in the ab plane through N-HÁ Á ÁO and O-HÁ Á ÁO 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.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: BT5739).
The molecule is twisted at the S-atom with the torsional angle of -70.67 (55)°, compared to the value of -69.2 (2)° in (II).
The dihedral angle between the sulfonyl benzene ring and the -SO 2 -NH-C-O segment is 78.4 (2)°, compared to the value of 87.2 (1)° in (II). Furthermore, the dihedral angle between the sulfonyl and the benzoyl benzene rings is 84.4 (2)°, compared to the value of 57.7 (1)° in (II).
Further, the crystal structure shows interesting H-bonding. Every water molecule forms four H-bonds with three different molecules of the title compound. One of the H-atoms of the water molecule forms simultaneous H-bonding with both the sulfonyl and the carbonyl oxygen atoms of the same molecule.

Experimental
The title compound was prepared by refluxing a mixture of m-methyl benzoic acid (0.02 mole), 4-chlorobenzenesulfonamide (0.02 mole) and excess phosphorous oxy chloride for 3 h on a water bath. The resultant mixture was cooled and poured into crushed ice. The solid, 4-Chloro-N-(3-methylbenzoyl)-benzenesulfonamide monohydrate, 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.
Needle like colourless single crystals of the title compound used in X-ray diffraction studies were obtained by slow evaporation of its ethanol-tetrahydrofuran solution at room temperature.

Refinement
The H atoms of the NH group and of the water molecule were located in a difference map and later restrained to N-H = 0.86 (2)Å and O-H = 0.85 (2) Å. The other H atoms were positioned with idealized geometry using a riding model with supplementary materials sup-2 the aromatic C-H = 0.93 Å and methyl C-H = 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. Fig. 1. Molecular structure of the title compound, showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level.