(E)-N′-(4-Bromobenzylidene)-p-toluenesulfonohydrazide

In the title compound, C14H13BrN2O2S, a novel sulfonamide derivative, intermolecular N—H⋯O and C—H⋯O hydrogen bonds link neighbouring molecules into different dimers along the b axis, generating R 2 2(8) and R 2 2(16) ring motifs. The dihedral angle between the benzene rings is 82.39 (13)°. The crystal structure is further stabilized by intermolecular π–π stacking interactions [centroid–centroid distances = 3.867 (2)–3.9548 (8) Å].


Comment
Sulfonamides were the first class of antimicrobial agents to be discovered. They inhibit dihydropteroate synthetase in the bacterial folic acid pathway. Although their clinical role has diminished, they are still useful in certain situations, because of its efficacy and low cost (Krygowski et al., 1998). Sulfonamides (sulfanilamide, sulfamethoxazole, sulfafurazole) are structural analogues of p-aminobenzoic acid (PABA) and compete with PABA to block its conversion to dihydrofolic acid.
These agents are generally used in combination with other drugs (usually sulfonamides) to prevent or treat a number of bacterial and parasitic infections (Tierney et al., 2006). Because of the above impotrtant features, we report the crystal structure of the title compound.
The title compund ( Fig. 1), is a novel sulfonamide derivative. Bond lengths (Allen et al., 1987) and angles are within the normal ranges and are comparable with the related staructures (Kia et al. 2008a,b;Mehrabi et al., 2008;Ali et al. 2007).
Experimental p-Tosylhydrazine (2 mmol) was added to a 50 ml refluxing ethanolic solution of 4-bromobenzaldehyde (2 mmol). The mixture was stirred for 2 h. After cooling, the colorless crystalline solid was isolated by filtration, washed with cold ethanol, and re-crystallized from ethanol.

Refinement
H atom bound to N1 was located from the difference Fourier map and refined freely; see Table 1. The rest of the hydrogen atoms were positioned geometrically and refined as riding model. A rotating group model was used for the methyl group.

Figures
supplementary materials sup-2  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.