N-[Amino(azido)methylidene]-4-methylbenzenesulfonamide

In the title molecule, C8H10N5O2S, the amino(azido)methyl and p-toluenesulfonyl moieties are inclined almost at right angles with respect to each other, making a dihedral angle of 83.49 (6)°. An intramolecular N—H⋯O hydrogen bond gives rise to the formation of six-membered ring with graph-set motif S(6). In the crystal, intermolecular N—H⋯O hydrogen bonding is responsible for the formation of dimers about inversion centers, which are linked through another N—H⋯O interaction along the b axis.


Comment
Sulfonamides are an important class of pharmaceutical compounds (Moree et al., 1991), they exhibit a broad spectrum of biological activites which include antibacterial, diuretic, hypoglycermic, anti-convulsant, HIV protease inhibitors and for the treatment of inflammatory rheumatic and non-rheumatic processes including onsets and traumatologic lesions (Arshad et al., 2008;Gennarti et al., 1994). Herein, we report the crystal structure of the title compound.
In the title compound ( Fig. 1), the azido group consisting of three nitrogen atoms carries cationic and anionic characters (Denny et al., 1980;Muller & Barnighausen, 1970). The bond distance N4-N5 is 1.112 (2) Å, which is nearly equal to a ≡bond distance between two nitrogen atoms i.e. 1.10 Å. The amino(azido)methyl (N1/C8/N2/N3/N4/N5) moiety is almost planer with r. m. s. deviation of 0.0156 Å and is oriented at a dihedral angle of 83.19 (5)° with respect to the toluene ring (C1-C7). The molecule exhibits both inter-and intra-molecular hydrogen bonding. The intermolecular hydrogen bonds result in dimers about inversion centers which are further connected through N-H···O type interactions and extended along the b axis (Tab. 1 & Fig. 2). The intramolecular hydrogen bonding N2-H2N···O2 gives rise to the formation of a six membered ring motif which can be represented mathematically as S 1 1 (6) (Bernstein et al., 1995).

Experimental
A mixture of 5-aminotetrazole monohydrate (4.85 mmol, 0.5 g) and p-toluenesulfonyl chloride (4.85 mmol, 0.92 g) was stirred in distilled water (10 ml) at room temperature while pH was maintained at 9-10 in accordance with (Arshad et al., 2009). The completion of the reaction was checked by TLC. As the reaction completed, the precipitates obtained were filtered, washed with distilled water and finally dried. Suitable crystals for X-ray analysis were grown from mixture of methanol and ethyl acetate (1:1) by slow evaporation. Yield of the reaction was 84% (0.97 g). mp 408-413 K.

Refinement
All H atoms were positioned geometrically with C methyl -H = 0.96 Å, C aromatic -H = 0.93 Å & N1-H = 0.8600 Å and treated as riding on their parent atoms with U iso (H) = 1.2U eq for aromatic & N1 H-atoms and 1.5U eq for methyl H-atoms.
The hydrogen atoms for primary amino group were located via fourier map allowed to refine with U iso (H) = 1.5 U eq (N).

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
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 > 2σ(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. The reflection 0 0 1 has been omitted as this was obscured by beamstop.