5-Amino-3-methyl-1-phenyl-1H-1,2,4-triazole

In the title compound, C9H10N4, the phenyl and triazole rings make a dihedral angle of 38.80 (2)°. N—H⋯N hydrogen bonds link the molecules, forming centrosymmetric R 2 2(8) rings; these rings are interconnected through a C(5) chain, building up a zigzag layer parallel to the (100) plane.

In the title compound, C 9 H 10 N 4 , the phenyl and triazole rings make a dihedral angle of 38.80 (2) . N-HÁ Á ÁN hydrogen bonds link the molecules, forming centrosymmetric R 2 2 (8) rings; these rings are interconnected through a C(5) chain, building up a zigzag layer parallel to the (100) plane.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: DN2319).

Comment
The aminotriazoles are crucial heterocyclic substances which have a great interest thanks to their biological and pharmacological activity (Kanazawa et al., 1988;Hashimoto et al., 1990) such as antitumoral and inhibition of cholesterol activity. In addition they have many applications in agriculture domain (Altman et al., 1993). Aminotriazole are useful binucleophilic agents that lead to polycondensed heterocycles (Genady et al., 2003;Karanik et al., 2003). However, the studies that deal with N 1 -phenyl-aminotriazole are very limited (Allouch et al., 2004). Until now only a few reactions were reported concerning the addition-cyclizations of bielectrophile compounds with N 1 -phenyl-aminotriazoles. In fact, these later are not well identified, this can be explicable by the existence of the tautomer equilibrium. That is why we have undertaken a crystallographic study.
In the title compound, the phenyl and the triazole rings remain planar with mean deviations from planarity of 0.0072 and 0.0049Å respectively. However, the two rings are twisted with respect to each other making a dihedral angle of 38.80 (2)°( The occurrence of N-H···N hydrogen bonds links the molecules through inversion centre to form R 2 2 (8) ring (Etter et al., 1990;Bernstein et al., 1995) and these rings are interconnected through C(5) chain to build up a like zigzag layer developping along the (1 0 0) plane (Table 1, Fig. 2) Experimental A mixture containing 3.56 g (0.02 mol) of N-phenyl ethyl acetydrazonateand 0.88 g (0.021 mol) of cyanamidein 20 ml of methanol was stirred and heated to reflux for 12 h. The solvent was removed under rotary evaporation. The crude product was washed with ether then recrystallized from methanol to give analytically pure crystals.

Refinement
All H atoms attached to C atoms were fixed geometrically and treated as riding with C-H = 0.96 Å (methyl) and 0.93 Å (aromatic) with U iso (H) = 1.2U eq (Phenyl) or U iso (H) = 1.5U eq (methyl). The methyl was found to be statistically disordered over two positions. H atoms attached to nitrogen were located in difference Fourier maps and included in the subsequent refinement using soft restraints (N-H= 0.90 (1)Å and H···H= 1.59 (2) Å) with U iso (H) = 1.2U eq (N).  Fig. 1. The molecular structure of the title compound with the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level. H atoms are represented as small spheres of arbitrary radii. Cell parameters from 2898 reflections a = 8.5110 (5) Å θ = 2.5-23.3º b = 11.2490 (8) Å µ = 0.08 mm −1 c = 10.1048 (7) Å T = 296 (7)   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 > 2sigma(F 2 ) is used only for calculating R-factors(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.