4-Amino-1-(2-benzoyl-1-phenylethyl)-3-phenyl-1H-1,2,4-triazol-5(4H)-thione

In the title compound, C23H20N4OS, the two phenyl rings of the diphenylpropanone fragment form a dihedral angle of 86.8 (1)°, and the third phenyl ring attached to the triazole ring is twisted from the latter at 40.1 (1)°. In the crystal, molecules are paired into centrosymmetric dimers via pairs of intermolecular N—H⋯O and N—H⋯S hydrogen bonds.

In the title compound, C 23 H 20 N 4 OS, the two phenyl rings of the diphenylpropanone fragment form a dihedral angle of 86.8 (1) , and the third phenyl ring attached to the triazole ring is twisted from the latter at 40.1 (1) . In the crystal, molecules are paired into centrosymmetric dimers via pairs of intermolecular N-HÁ Á ÁO and N-HÁ Á ÁS hydrogen bonds.   Table 1 Hydrogen-bond geometry (Å , ).

Comment
In continuation of structural study of 1,2,4-triazole-5(4H)-thione derivatives in our group (Wang et al., 2011), we present here the crystal structure of the title compound, (I).

Experimental
The title compound was synthesized by the reaction of the chalcone (2.0 mmol) with 4-amino-3-phenyl-4H-1,2,4-triazole-5thiol (2.0 mmol) by refluxing in ethanol for 24 h. The reaction progress was monitored via TLC. The resulting precipitate was filtered off, washed with cold ethanol, dried and purified to give the target product as colorless solid in 87% yield. Crystals of (I) suitable for single-crystal X-ray analysis were grown by slow evaporation of a solution in chloroform-ethanol (1:1).

Refinement
The H atoms attached to N atoms were located on a difference map, and isotropically refined using bond length restraint N-H = 0.91 (2) Å. C-bound H atoms were positioned geometrically (C-H = 0.95-1.00 Å), and refined as riding, with U iso (H) = 1.2-1.5U eq (C). Fig. 1. View of the molecule of (I) showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 60% probability level.

Figures
supplementary materials sup-2 4-Amino-1-(2-benzoyl-1-phenylethyl)-3-phenyl-1H-1,2,4-triazol-5(4H)-thione 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.