3-{[5-(4-Chlorophenyl)-3-methyl-1H-pyrazol-1-yl]methyl}-4-m-tolyl-1H-1,2,4-triazole-5(4H)-thione

In the title compound, C20H18ClN5S, the toluene and triazole rings are oriented almost perpendicular to each other, making a dihedral angle of 89.97 (9)°, whereas the dihedral angle between cholorophenyl and pyrazole rings is 54.57 (11)°. In the crystal, pairs of N—H⋯N hydrogen bonds link the molecules into inversion dimers. Weaker C—H⋯S and C—H⋯Cl interactions are also present.

In the title compound, C 20 H 18 ClN 5 S, the toluene and triazole rings are oriented almost perpendicular to each other, making a dihedral angle of 89.97 (9) , whereas the dihedral angle between cholorophenyl and pyrazole rings is 54.57 (11) . In the crystal, pairs of N-HÁ Á ÁN hydrogen bonds link the molecules into inversion dimers. Weaker C-HÁ Á ÁS and C-HÁ Á ÁCl interactions are also present.
There is one molecule in the asymmetric unit and four molecules in the unit cell. 1, 2, 4 Triazole ring is oriented almost perpendicular to the toluene ring and the torsion angle between the two rings is 92.6 (2) ° as calculated on the basis of C13-N3-C14-C20 atoms. The diazole ring and the adjacent cholorobenzene ring adopt a twisted geometry and the torsion angle between them is -127.2 (2) ° as calculated using C3-C4-C7-N2 atoms. The molecular assembly is mainly built upon a reciprocal pair of intermolecular N4-H4···N1 type hydrogen bonds between two adjacent molecules which result in the formation of a molecular dimer. The D-H···A distance in each case is 2.02 Å. There are also some C -H···π interactions, a C-H···S interaction and a C-H···Cl interaction which help to stabilize the molecular assembly.
The S1 atom accepts the H6 atom from C6 to form a C-H···S type weaker hydrogen bond at a distance of 2.998 Å with a D-H···A angle of 143.87°. Similarly the Cl1 atom accepts the H14 atom from C20 to form a C-H···Cl type weaker hydrogen bond at a distance of 2.978 Å with a D-H···A angle of 120.0°.

Experimental
A solution of 2 N sodium hydroxide solution (2 ml) was added in dropwise to a solution of 5 mmol (2.07 g) 2-{[5-(4chlorophenyl)-3-methyl-1H-pyrazol-1-yl]acetyl}-N-(3-methylphenyl)hydrazinecarbothioamide in 50 ml e thanol. The reaction mixture was then refluxed for 7 h, cooled and filtered. The filtrate was acidified with 2 N hydrochloric acid. The separated solid was collected, washed, and crystallized from ethanol in an excellent yield (92%). Single crystals suitable for X-ray diffraction were obtained from slow evaporation solution of the title compound in ethanol at room temperature (M.p. 433-435 K).

Refinement
The methyl group H atoms were geometrically placed at idealized positions and refined using a riding model with d(C-H) = 0.96 Å and U iso = 1.5Ueq(C). The H atom on N atom was located in the difference map and was refined isotropically.
All other H atoms bound to C were located in the difference map but were refined using a riding model with d(C-H) = 0.93 Å for aromatic and 0.97 Å for CH 2 group with U iso (H) = 1.2U eq (C). program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012) and Mercury (Macrae et al., 2008); software used to prepare material for publication: publCIF (Westrip, 2010).

Special details
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s 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 > σ(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.