N-(2-Methylphenyl)-6-(1H-pyrazol-1-yl)pyridazin-3-amine

The title compound, C14H13N5, crystallizes with two crystallographically independent molecules in the unit cell. The two molecules form dimers through intermolecular N—H⋯N and C—H⋯N hydrogen bonds. The hydrogen-bonding motifs are R 2 2(8) for both the N—H⋯N and C—H⋯N interactions. The pyrazole and pyrimidine rings form dihedral angles of 6.2 (3) and 8.3 (3)° with each other and the dihedral angles between the pyrazole and benzene rings are 54.9 (2) and 58.6 (2)°. The benzene rings of neighbouring dimers also exhibit C—H⋯π interactions.

The title compound, C 14 H 13 N 5 , crystallizes with two crystallographically independent molecules in the unit cell. The two molecules form dimers through intermolecular N-HÁ Á ÁN and C-HÁ Á ÁN hydrogen bonds. The hydrogen-bonding motifs are R 2 2 (8) for both the N-HÁ Á ÁN and C-HÁ Á ÁN interactions. The pyrazole and pyrimidine rings form dihedral angles of 6.2 (3) and 8.3 (3) with each other and the dihedral angles between the pyrazole and benzene rings are 54.9 (2) and 58.6 (2) . The benzene rings of neighbouring dimers also exhibit C-HÁ Á Á interactions.
lolylpyridazine has shown inhibitory action against glycogen synthase kinase 3 (Xiao et al., 2006). In continuation of our work on the synthesis and reactions of azolylpyridazines, we have isolated crystals of the title compound, (Fig. 1).
The title compound contains pyrazole, pyridazine and benzene rings. In the asymmetric unit there are two molecules which differ from one another crystallographically.
In one molecule (containing C1-C14), the pyrazole ring is oriented at dihedral angles of 6.16 (30)° and 54.91 (21)°w ith the pyridazine and benzene rings, respectively. In the second molecule, the pyrazole ring exhibits dihedral angles of 8.26 (34)° and 58.57 (20)° with the pyridazine and benzene rings, respectively. Through intermolecular N-H···N and C-H···N hydrogen bonds the two molecules form dimers with hydrogen bonding ring motifs of R 2 2 (8) (Bernstein et al., 1995). C-H···π interactions between the benzene rings are also observed in the structure of the title compound (Table 1, Cg1 is the centroid of benzene ring (C15-C20)).
Experimental 3-Chloro-6-(1H-pyrazol-1-yl)pyridazine (1.68 g, 9.33 mmol) and 2-toluidine (1 g, 9.34 mmol) were refluxed in dimethylformamide (DMF) for 2 h. The reaction mixture was concentrated under vacuum and poured in cold water. The precipitates obtained were filtered, washed with distilled water and dried to give 51.28% yield. The product obtained was purified by column chromatography and recrystallized in benzene.

Refinement
In the absence of significant anomalous scattering effects, Friedel pairs were merged. The atoms of one of the benzene rings were refined with equal anisotropic thermal parameters.
H-atoms were positioned geometrically, with N-H = 0.86 Å, C-H = 0.93 and 0.96 Å for aromatic rings and metyl H-atoms and constrained to ride on their parent atoms, with U iso (H) = xU eq (C, N), where x = 1.5 for methyl H and x = 1.2 for all other H atoms. Fig. 1. View of the title compound with the atom numbering scheme. The thermal ellipsoids are drawn at the 50% probability level. H-atoms are shown as small spheres of arbitrary radii.

Special details
Geometry. All e.s. 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.