1-Methyl-3-phenylthiourea

The title compound, C8H10N2S, was prepared by reaction of methylamine solution, KOH and phenyl-isothiocyanate in ethanol. It adopts a syn-Me and anti-Ph conformation relative to the C=S double bond. The dihedral angle between the N—C(=S)—N thiourea and phenyl planes is 67.83 (6)°. In the crystal, the molecules centrosymmetrical dimers by pairs of N(Ph)—H⋯S hydrogen bonds. The dimers are linked by N(Me)—H⋯S hydrogen bonds into layers parallel to (100).

The title compound, C 8 H 10 N 2 S, was prepared by reaction of methylamine solution, KOH and phenyl-isothiocyanate in ethanol. It adopts a syn-Me and anti-Ph conformation relative to the C S double bond. The dihedral angle between the N-C( S)-N thiourea and phenyl planes is 67.83 (6) . In the crystal, the molecules centrosymmetrical dimers by pairs of N(Ph)-HÁ Á ÁS hydrogen bonds. The dimers are linked by N(Me)-HÁ Á ÁS hydrogen bonds into layers parallel to (100).

Comment
Thioureas have been studied for many years because of their broad antibiosis and sterilibzation properties. Recent years study shows that thioureas not only can be used to kill insects and adjust plant growth but also have anti-viral activities (Madan & Taneja, 1991;Borisova et al., 2007). From our early quantum study on these compounds we find that they have several active centers and cart form polyligand complexes with metals easily (Xu et al., 2004). These complexes are widely used as anti-medicines. Therefore study on thioureas has important impact on the future. In order to search for new compounds with higher bioactivity, the title compound was synthesized.
In the title compound, C 8 H 10 N 2 S (I), the bond lengths and angles are in a good agreement with those found in the related compounds (Ji et al., 2002;Wenzel et al. 2011). Compound I adopts a cis-Me and trans-Ph conformation relative to the C═S double bond (Figure 1). The dihedral angle between the N1-C7(═S1)-N1 thiourea and phenyl planes is 67.83 (6)°.

Experimental
The title compound was prepared by reaction of methylamine solution (40%, 0.05 mol, 5.5 ml), KOH (0.15 mol,8.4 g) and phenyl-isothiocyanate(0.05 mol, 4.65 g) in the ethanol solution (40 ml) at room temperature. Single-crystals of the title compound suitable for X-ray measurements was obtained by recrystallization from ethanol/acetone (v/v=1:1) at room temperature.

Refinement
The hydrogen atoms of the amino groups were localized in the difference Fourier map and refined isotropically. The other hydrogen atoms were placed in the calculated positions with C-H = 0.93 Å (aryl-H) and 0.96 Å (methyl-H) and refined in the riding model with fixed isotropic displacement parameters: U iso (H) = 1.5U eq (C) for the CH 3 group and 1.2U eq (C) for the other CH groups.   Secondary atom site location: difference Fourier map Hydrogen site location: difference Fourier map H atoms treated by a mixture of independent and constrained refinement w = 1/[σ 2 (F o 2 ) + (0.0587P) 2 + 0.1272P] where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.24 e Å −3 Δρ min = −0.24 e Å −3 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq S1 0.16423 (