Ethyl 2-[3-(4-nitrobenzoyl)thioureido]benzoate

In the title compound, C17H15N3O5S, the nitro and thioureido groups are twisted by 7.2 (7) and 21.4 (2)°, respectively, from the nitrobenzene ring plane whereas the thioureido and the ethyl ester group make dihedral angles of 43.0 (1) and 18.0 (2)°, respectively, with the benzene rings to which they are attached. Intramolecular N—H⋯O hydrogen-bonding interactions are observed. In the crystal, intermolecular N—H⋯O hydrogen bonds connect the molecules into chains running along the a axis.

In the title compound, C 17 H 15 N 3 O 5 S, the nitro and thioureido groups are twisted by 7.2 (7) and 21.4 (2) , respectively, from the nitrobenzene ring plane whereas the thioureido and the ethyl ester group make dihedral angles of 43.0 (1) and 18.0 (2) , respectively, with the benzene rings to which they are attached. Intramolecular N-HÁ Á ÁO hydrogen-bonding interactions are observed. In the crystal, intermolecular N-HÁ Á ÁO hydrogen bonds connect the molecules into chains running along the a axis.

Related literature
For general background to the chemistry of thiourea derivatives, see: Ugur et al. (2006). For related compounds with antitubercular properties, see: Huebner et al. (1953) and for other biological activities of thiourea compounds, see: Glasser & Doughty (1964). For related structures, see: Saeed et al. (2008a,b). For the cytotoxicity of anticancer drugs to normal cells in cancer therapy, see: Saeed et al. (2010). For the herbicidal activity of thiourea derivatives, see: Zheng et al.  Table 1 Hydrogen-bond geometry (Å , ).

Comment
Industrial production and the use of transition elements can cause environmental pollution. However, some of these metals are present in trace amounts as essential elements for biological systems and also play an important role in bioinorganic chemistry. In order to understand the role of these metal ions in biological systems, structural studies of the biological compounds and their metal complexes are extremely important. Compounds containing carbonyl and thiocarbonyl groups occupy an important position among organic reagents as potential donor ligands for transition metal ions (Ugur et al., 2006).
Thioureas are also known to exhibit a wide range of biological activities including antiviral, antibacterial, anticancer (Saeed et al., 2010), antifungal, antitubercular, antithyroidal, herbicidal andinsecticidal activities (Huebner et al., 1953) and as agrochemicals (Saeed et al., 2008a). An example is furnished by 1-benzoyl-3-(4,5-disubstituted-pyrimidine-2-yl)-thioureas, which have excellent herbicidal activity (Zheng et al., 2004). Thioureas are also well known chelating agents for transition metals and the complexes also show varied biological activities (Glasser & Doughty, 1964). Thioureas and substituted thioureas are also known as epoxy resin curing agents (Saeed et al., 2008b). We became interested in the synthesis of Naroyl, N'-arylthioureas as intermediates towards some new novel heterocycles and for the systematic study of their bioactive complexes and their function as epoxy resin curing agents. Here we present the structure of the title compound (I). The molecule is not planar. The nitro group is slightly twisted (7.2 (7)°) from the benzene ring plane of C1-C6. The thioureido group is 21.4 (1)° from the benzene ring plane of C1-C6 and 43.0 (1)° from the benzene ring plane of C9-C14. The ethyl ester group is twisted 18.0 (2)° from the benzene ring plane of C9-C14. Both intra-and inter-molecular N-H···O H-bond interactions are observed in the crystal lattice. The intermolecular N2-H2N···O3 H-bonding interactions, connect the molecules into 1-D chains running along the a-axis. There seems to be no significant π···π nor C-H···π interaction in the crystal lattice.
There is no residual solvent accessible void volume in the unit cell.

Experimental
A solution of 4-nitrobenzoyl chloride (0.01 mol) in dry acetone (80 ml) was added dropwise to a suspension of ammonium thiocyanate (0.01 mol) in acetone (50 ml) and the reaction mixture was refluxed for 45 minutes. After cooling to room temperature, a solution of ethyl 2-aminobenzoate (0.01 mol) in acetone (25 ml) was added and the resulting mixture refluxed for 2 h. The reaction mixture was poured into five times its volume of cold water, upon which the thiourea precipitated. The product was recrystallized from ethyl acetate as intensely yellow crystals.

Refinement
All of the C-bound H atoms are observable from difference Fourier map but are all placed at geometrical positions with C-H = 0.93, 0.96 and 0.97Å for phenyl methyl and methylene H-atoms. All C-bound H-atoms are refined using riding model with U iso (H) = 1.2U eq (Carrier).
supplementary materials sup-2 The N-bound H atoms are located from a difference Fourier map and refined isotropically. Six restraints are related to the refinement of O2 using isotropic restraints of standard deviation of 0.001 in the anisotropic atom displacement components.  Fig. 1. The ORTEP plot of the compound was shown at 30% probability thermal ellipsoids with the atom numbering scheme.

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 > 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.