2-Chloro-N-[(2-methylphenyl)sulfonyl]acetamide

In the title compound, C9H10ClNO3S, the amide H atom is syn with respect to the ortho-methyl group in the benzene ring and the C—S—N—C torsion angle is −66.9 (2)°. An intramolecular N—H⋯Cl hydrogen bond occurs. The crystal structure features inversion-related dimers linked by pairs of N—H⋯O hydrogen bonds.

In the title compound, C 9 H 10 ClNO 3 S, the amide H atom is syn with respect to the ortho-methyl group in the benzene ring and the C-S-N-C torsion angle is À66.9 (2) . An intramolecular N-HÁ Á ÁCl hydrogen bond occurs. The crystal structure features inversion-related dimers linked by pairs of N-HÁ Á ÁO hydrogen bonds.

Related literature
For the sulfanilamide moiety in sulfonamide drugs, see; Maren (1976). For its ability to form hydrogen bonds in the solid state, see; Yang & Guillory (1972). For hydrogen-bonding preferences of sulfonamides, see; Adsmond & Grant (2001). For the effect of substituents on the crystal structures of sulfonoamides, see: Gowda et al. (2008aGowda et al. ( ,b, 2010 Experimental Crystal data

Comment
The molecular structures of sulfonamide drugs contain the sulfanilamide moiety (Maren, 1976). The propensity for hydrogen bonding in the solid state, due to the presence of various hydrogen bond donors and acceptors can give rise to polymorphism (Yang & Guillory, 1972). The hydrogen bonding preferences of sulfonamides has also been investigated (Adsmond & Grant, 2001). The nature and position of substituents play a significant role on the crystal structures of N-(aryl)sulfonoamides (Gowda et al., 2008a(Gowda et al., ,b, 2010. As a part of studying the substituent effects on the structures of this class of compounds, the structure of 2-chloro-N-(2-methylphenylsulfonyl)-acetamide (I) has been determined. The conformations of the N-H and C=O bonds of the SO 2 -NH-CO-C segment in the structure are anti to each other ( Fig. 1), similar to that observed in N-(phenylsulfonyl)acetamide (II) (Gowda et al., 2010), N-(phenylsulfonyl)-2,2-dichloroacetamide (III) (Gowda et al., 2008b) and N-(4-methylphenylsulfonyl)-2,2-dichloroacetamide (IV) (Gowda et al., 2008a).
The molecule in (I) is bent at the S-atom with a C1-S1-N1-C7 torsion angle of -67.0 (3) In the crystal structure, the pairs of intermolecular N-H···O hydrogen bonds (Table 1) link the molecules through inversion-related dimers into zigzag chains running in the bc-plane. Part of the crystal structure is shown in Fig. 2.

Experimental
The title compound was prepared by refluxing 2-methylbenzenesulfonamide (0.10 mole) with an excess of chloroacetyl chloride (0.20 mole) for about an hour on a water bath. The reaction mixture was cooled and poured into ice cold water.
The resulting solid was separated, washed thoroughly with water and dissolved in warm dilute sodium hydrogen carbonate solution. The title compound was reprecipitated by acidifying the filtered solution with glacial acetic acid. It was filtered, dried and recrystallized from ethanol. The purity of the compound was checked by determining its melting point. It was further characterized by recording its infrared spectra.
Prism like colorless single crystals of the title compound used in X-ray diffraction studies were obtained from a slow evaporation of an ethanolic solution of the compound.

Refinement
The H atom of the NH group was located in a difference map and later restrained to the distance N-H = 0.86 (3) Å. The other H atoms were positioned with idealized geometry using a riding model with C-H = 0.93-0.97 Å. All H atoms were refined with isotropic displacement parameters (set to 1.2 times of the U eq of the parent atom).
The U ij components of C3, C4 and C5 were restrained to approximate isotropic behavoir. Fig. 1. Molecular structure of the title compound, showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level.

Special details
Geometry. All e.s. 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.