5-(2-Methylphenyl)-1,3,4-thiadiazol-2-amine

The asymmetric unit of the title compound, C9H9N3S, contains two crystallographically independent molecules, in which the thiadiazole and tolyl rings are oriented at dihedral angles of 32.25 (3) and 74.50 (3)°. An intramolecular C—H⋯S interaction results in the formation of a five-membered ring. In the crystal structure, intermolecular N—H⋯N hydrogen bonds link the molecules into chains along the a axis. A π–π contact between the thiadiazole rings [centroid–centroid distance = 3.910 (3) Å] may further stabilize the structure. There is also a weak C—H⋯π interaction.

Experimental Crystal data

Experimental
For the preparation of the title compound, 3-methyl-benzoic acid (5 mmol) and thiosemicarbazide (5 mmol) were added in toluene (50 ml), and kept in the oil bath at 363 K for 6 h. After cooling, the crude product precipitated and was filted.
Crystals suitable for X-ray analysis were obtained by slow evaporation of an acetone solution.

Refinement
H atoms were positioned geometrically, with N-H = 0.86 Å (for NH 2 ) and C-H = 0.93 and 0.96 Å for aromatic and methyl H, respectively, and constrained to ride on their parent atoms, with U iso (H) = xU eq (C,N), where x = 1.5 for methyl H and

Data collection
Enraf-Nonius CAD-4 diffractometer R int = 0.0000 Radiation source: fine-focus sealed tube θ max = 27.0º Monochromator: graphite θ min = 1.7º 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.