3-Methylsulfanyl-5-phenyl-1,2,4-triazine

In the molecule of the title compound, C10H9N3S, the dihedral angle between the triazine and phenyl rings is 11.77 (7)°. In the crystal, molecules are linked by π–π stacking interactions [centroid–centroid distances = 3.7359 (3) and 3.7944 (4) Å], forming layers parallel to the bc plane.

In the molecule of the title compound, C 10 H 9 N 3 S, the dihedral angle between the triazine and phenyl rings is 11.77 (7) . In the crystal, molecules are linked bystacking interactions [centroid-centroid distances = 3.7359 (3) and 3.7944 (4) Å ], forming layers parallel to the bc plane.

Comment
1,2,4-Triazine derivatives have been widely studied in terms of their synthetic methodologies and reactivity since some of these compounds were reported to have promising biological activities, including antimicrobial, inflammatory, analgesic, antiviral and anthelminitic activities (Abd el-Samii, 1992; Kidwai et al., 1998;Holla et al., 2001;Abdel-Rahman et al., 1999;Hay et al., 2004;Sztanke et al., 2005). We synthesized the title compound and describe its structure here.

Experimental
To a solution of thiosemicarbazide (50 g, 0.55 mol) in absolute ethanol (500 ml) was added iodomethane (34.1 ml, 0.55 mol). The reaction mixture was stirred at reflux for 3 h then cooled overnight in the refrigerator. The crystals formed were filtered on a Buchner funnel, washed with ethanol and dried in vacuo to give the S-methylthiosemicarbazide iodohydrate beige powder (123 g). An aqueous solution (200 ml) of S-methylthiosemicarbazide iodohydrate (20 g, 85.8 mmol) was added to an aqueous solution (120 ml) of phenyl glyoxal (15.65 g, 103 mmol) and sodium bicarbonate (10 g, 94.4 mmol) at 5°C. The temperature was maintained at 5°C for 6 h then the reaction medium was extracted with dichloromethane.
The organic phases are combined, dried over magnesium sulfate, filtered and evaporated under reduced pressure. The crude material was purified by column on silica (hexane/EtOAc 9:1 v/v) as eluent. The title compound (13.95 g) was obtained as yellow crystals (79% yield) on slow evaporation of the solvent.

Refinement
H atoms were located in a difference Fourier map and treated as riding, with C-H = 0.93-0.96 Å and U iso (H) = 1.2 U eq (C) or 1.5 U eq (C) for methyl H atoms. One outlier (-1 7 1) was omitted in the last cycles of refinement.

Figure 1
The molecular structure of the title compound with displacement ellipsoids drawn at the 50% probability level. H atoms are represented as small circles. 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.