3-Chloro-N-(diphenylcarbamothioyl)benzamide

In the title compound, C20H15ClN2OS, the bond lengths and angles in the thiourea group are typical of thiourea derivatives. The C—N bond lengths in the center of the molecule are shorter than the normal C—N single bond due to the resonance effects in this part of the molecule. The conformation of the title molecule with respect to the thiocarbonyl and carbonyl groups is twisted, as reflected by the C—N—C—O and C—N—C—N torsion angles of −4.4 (6) and −53.3 (5)°, respectively. Pairs of the molecules are linked into centrosymmetric dimers, stacked along the c axis via intermolecular N—H⋯S interactions. There are also weak intermolecular C—H⋯O and C—H⋯S contacts in the structure.

In the title compound, C 20 H 15 ClN 2 OS, the bond lengths and angles in the thiourea group are typical of thiourea derivatives. The C-N bond lengths in the center of the molecule are shorter than the normal C-N single bond due to the resonance effects in this part of the molecule. The conformation of the title molecule with respect to the thiocarbonyl and carbonyl groups is twisted, as reflected by the C-N-C-O and C-N-C-N torsion angles of À4.4 (6) and À53.3 (5) , respectively. Pairs of the molecules are linked into centrosymmetric dimers, stacked along the c axis via intermolecular N-HÁ Á ÁS interactions. There are also weak intermolecular C-HÁ Á ÁO and C-HÁ Á ÁS contacts in the structure.   Table 1 Hydrogen-bond geometry (Å , ). Symmetry codes: (i) Àx þ 1; Ày þ 1; Àz; (ii) Àx; Ày þ 1; Àz þ 1; (iii) x; y À 1; z.

Comment
Thioureas and their metal complexes are an important class of compounds with a wide range of biological applications such as antitubercular, antithroid, anthelmintic, antibacterial, insecticidal and rodenticidal properties (Schroeder, 1955;Huebhr et al., 1953;Madan et al., 1991). Another area of the application of thiourea derivatives is analytical chemistry where some of these compounds have been used in the liquid-liquid extraction and separation of some transition metal ions (Koch, 2001).
Recently, a number of works on the structural and spectral properties of the thiourea derivatives and their metal complexes have appeared in the literature (Özer et al., 2009;Mansuroğlu et al., 2008;Uğur et al., 2006;Arslan et al., 2003c). We report here the crystal structure of one of them. The synthesis involves the reaction of a 3-chlorobenzoyl chloride with potassium thiocyanate in dry acetone followed by condensation of the 3-chlorobenzoyl isothiocyanate with the diphenylamine.
As can be seen from the packing diagram ( Fig. 2), intermolecular N-H···S hydrogen bond (Table 1) links the molecules into dimers, which are stacked along the c-axis. The other intermolecular contacts, C-H···O and C-H···S, are also listed in Table 1.

Experimental
The title compound was prepared with a procedure similar to that reported in the literature (Arslan et al., 2003a). A solution of 3-chlorobenzoyl chloride (0.01 mol) in acetone (50 cm 3 ) was added dropwise to a suspension of potassium thiocyanate (0.01 mol) in acetone (30 cm 3 ). The reaction mixture was heated under reflux for 30 min, and then cooled to room temperature.
A solution of diphenylamine (0.01 mol) in acetone (10 cm 3 ) was added and the resulting mixture was stirred for 2 h.
Hydrochloric acid (0.1 N, 300 cm 3 ) was added to the solution, which was then filtered. The solid product was washed with  Fig. 1. The molecular structure of (I). Displacement ellipsoids are drawn at the 50% probability level.

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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.