(E)-N′-Benzylidene-p-toluenesulfonohydrazide

In the title compound, C14H14N2O2S, a novel sulfonamide derivative, an intramolecular C—H⋯O hydrogen bond generates an S(5) ring motif. The molecule adopts a twisted E configuration around the C=N bond. An intermolecular N—H⋯O hydrogen bond generates an R 2 2(8) ring motif. The dihedral angle between the rings is 85.37 (9)°. The H atoms of the methyl group have rotational disorder with refined site occupancies of ca 0.63/0.37. In the crystal structure, intermolecular N—H⋯O hydrogen bonds link neighbouring molecules into dimers which stack along the a axis with a centroid–centroid distance of 3.8856 (10) 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 analogs 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). Some of the applications of sulfonamides are the anti-infective agents of choice, as follows: Bacteria as Human Pathogens, such as Antibiotic Treatment of Infections Caused by Gram-Positive Bacilli and Gram-negative Haemophilus ducreyi and Haemophilus aegyptius, Alternative Drug for treatment of Chlamydia related diseases (including C. trachomatis, Chlamydia psittaci, Chlamydia pneumonia), Anti-malarial Agents as Dihydropteroate synthetase inhibitors, alternative drugs in tuberculosis treatment, long term treatment of leprosy, treatment of ocular infections. In the latter treatment causative organisms must be identified, and it is preferable to use a drug that is not given systemically. Sulfonamides are also assumed as permitted antibiotics in Pregnancy (Kayser et al., 2004).
The title compound (I) (Fig. 1), is a novel sulfonamide derivative. Bond lengths and angles are within the normal ranges (Allen et al., 1987) and are comparable with the similar staructures (Ali et al. 2007). An intramolecular C-H···O hydrogen bond generate S(5) ring motif (Bernstein et al., 1995). The molecule adopts a twisted E configuration around the C═N. An intermolecular N-H···O hydrogen bond genarate R 2 2 (8) ring motif (Bernstein et al., 1995). The dihedral angle between the phenyl rings is 85.37 (9)°. None of the H atoms of the methyl group was clearly resolved in the difference Fourier map and they were disordered over six positions and refined with site-occupancy factors of 0.62 (3) and 0.38 (3) for the major and minor componenets, respectively. In the crystal structure, intermolecular N-H···O interactions link neighbouring molecules into dimers which stacked along the a-axis. The short distance between the centroids of the six-membered rings prove an exsistence of the π-π interactions with centroid to centroid dsiatnce of 3.8856 (10) Å. The crystal structure is stabilized by intramolecular C-H···O, intermolecular N-H···O hydrogen bonds and π-π satcking.
Experimental p-Tosylhydrazine (3 mmol) was added to a stirred solution of benzaldehyde (3 mmol) in 2 ml of toluene at 20-25° C. The mixture was stirred for 6 h at 110° C. After cooling, the colorless crystalline solid was isolated by filtration, washed with cold toluene, and re-crystallized from ethanol.

Refinement
H atom bound to N1 was located from a difference Fourier map and refined freely. The methyl hydrogen atoms were located from the difference Fourier map and refined freely with the parent atom. The rest of the hydrogen atoms were positioned geometrically and refined as riding model.   as those based on F, and R-factors based on ALL data will be even larger.