1-(2-Chlorobenzoyl)-3-(2,3-dimethylphenyl)thiourea

The dihedral angle between the two phenyl groups in the title compound, C16H15ClN2OS, is 14.88 (4)°. An intramolecular N—H⋯O hydrogen bond occurs. In the crystal, pairs of N—H⋯S hydrogen bonds link the molecules into centrosymmetric dimers.

The dihedral angle between the two phenyl groups in the title compound, C 16 H 15 ClN 2 OS, is 14.88 (4) . An intramolecular N-HÁ Á ÁO hydrogen bond occurs. In the crystal, pairs of N-HÁ Á ÁS hydrogen bonds link the molecules into centrosymmetric dimers. 192 parameters H-atom parameters constrained Á max = 0.32 e Å À3 Á min = À0.31 e Å À3 Table 1 Hydrogen-bond geometry (Å , ). MR is grateful to The Quaid-i-Azam University, Islamabad, for financial support for a postdoctoral fellowship.

M. Khawar Rauf, Masahiro Ebihara and Amin Badshah Comment
The background to this study has been set out in our previous work for the structural chemistry of N, N′-disubstituted thiourea (Rauf et al., 2012) and their coordination chemistry. Herein, as a continuation of these crytallographic studies, the structure of the title compound (I) is described, Fig. 1

. Compared to N-benzoyl-N′-phenylthioureas [Cambridge Structural
Database (Mogul Version 1.7; Allen, 2002], the methyl substitutions at C(10) and C(11)on phenyl ring, implies no significant effect on these bond lengths. and show the molecule to exist in the thione form with typical thiourea C-S and C-O bonds, as well as shortened C-N bond lengths. The dihedral angles to the O(1) C(1) N(1) C(2) N(2)S(1) plane are 79.89 (2)° for the ring formed by C(3) to C(8) and 65.32 (2)° for the ring formed by C(9) to C(14). An intramolecular N -H···O H-bond is present (Table 1), forming a six-membered ring commonly observed in this class of compounds (Rauf et al., 2012). In the crystal packing of (I), intermolecular N-H···S H-bonds link the molecules into centrosymmetric dimers (Fig.2).
The reaction mixture was then poured into acidified water and stirred well. The solid product was separated and washed with deionized water and purified by recrystallization from methanol/ 1,1-dichloromethane (1:1 v/v) to give fine crystals of the title compound (I), with an overall yield of 95% (3.02 g). M.P; 180-181°C Anal. calcd. for C 16 H 15 Cl N 2 O S; C, 60.28 H,4.74 N,8.79 S,10.06 Found: C,60.22 H,4.73 N,8.78 S,10.01.

Refinement
Hydrogen atoms were included in calculated positions and refined as riding on their parent atom with N-H = 0.88 Å and U iso (H) = 1.2U(N eq ), C aromatic -H = 0.95 Å and U iso (H) = 1.2U(C eq ) or C-H = 0.98 Å and U iso (H) = 1.5U(C eq ), for methyl C atoms.  ORTEP of (I). Displacement ellipsoids are drawn at the 50% probability level. Hydrogen bonds shown as dashed lines.

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.