2,2-Dimethyl-N-(phenylsulfonyl)acetamide

In the title compound, C10H13NO3S, the N—H and C=O bonds in the SO2—NH—CO—C segment are anti to each other. The benzene ring and the SO2—NH—CO—C segment form a dihedral angle of 87.4 (1)°. The crystal packing features inversion-related dimers linked by pairs of N—H⋯O hydrogen bonds.

In the title compound, C 10 H 13 NO 3 S, the N-H and C O bonds in the SO 2 -NH-CO-C segment are anti to each other. The benzene ring and the SO 2 -NH-CO-C segment form a dihedral angle of 87.4 (1) . The crystal packing features inversion-related dimers linked by pairs of N-HÁ Á ÁO hydrogen bonds.

Related literature
For sulfonamide drugs, see: Maren (1976). It has been postulated that the propensity for hydrogen bonding in the solid state can give rise to polymorphism due to the presence of various hydrogen-bond donors and acceptors, see: Yang & Guillory (1972). The hydrogen bonding preferences of sulfonamides have also been investigated, see: Adsmond & Grant (2001). The nature and position of substituents play a significant role in the crystal structures of N-(aryl)sulfonoamides, see: Gowda et al. (2008a,b,c Table 1 Hydrogen-bond geometry (Å , ). (5) 2.898 (4) 160 (4) Symmetry code: (i) Àx þ 1; Ày þ 1; Àz.

Comment
Sulfonamide drugs that exhibit antibacterial activity contain the sulfanilamide moiety (Maren, 1976). It has been postulated that 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 have also been investigated (Adsmond & Grant, 2001). The nature and position of substituents play a significant role in the crystal structures of N-(aryl)sulfonoamides (Gowda et al., 2008a, b, c).
In the crystal the molecules form inversion-related dimers along the c axis, linked by pairs of N-H···O(S) hydrogen bonds (Table 1, Fig.2).

Experimental
The title compound was prepared by refluxing benzenesulfonamide (0.10 mole) with an excess of isobutanoyl 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 characterized by recording its infrared spectra. Single crystals of the title compound used for 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 and its position refined with N-H = 0.81 (4) Å. The other H atoms were positioned with idealized geometry using a riding model with C-H = 0.93-0.98 Å.
All H atoms were refined with isotropic displacement parameters (set to 1.2 times of the U eq of the parent atom).