1-(Benzothiazol-2-yl)-3-(4-nitrobenzoyl)thiourea

The molecule of the title compound, C15H10N4O3S2, is almost planar (r.m.s. deviation = 0.1Å for all non-H atoms). An intramolecular N—H⋯O=C hydrogen bond is observed. In the crystal, molecules are connected into layers parallel to (10) by a classical intermolecular hydrogen bond from the second NH group to a nitro O atom and by three weak hydrogen bonds of the C—H⋯X type (X = O or Sthione).

The molecule of the title compound, C 15 H 10 N 4 O 3 S 2 , is almost planar (r.m.s. deviation = 0.1Å for all non-H atoms). An intramolecular N-HÁ Á ÁO C hydrogen bond is observed. In the crystal, molecules are connected into layers parallel to (101) by a classical intermolecular hydrogen bond from the second NH group to a nitro O atom and by three weak hydrogen bonds of the C-HÁ Á ÁX type (X = O or S thione ).

Comment
Thiourea and its derivatives have found extensive applications in the field of medicine, agriculture and analytical chemistry.
They are known to exhibit a wide variety of biological activities such as antiviral, anti-bacterial, antifungal, antitubercular, herbicidal, insecticidal and some epoxy resin curing agents containing amino functional groups (Saeedet al., 2008a,b,c).
They have found broad areas of application e.g. in anion recognition, nonlinear optics and catalysis, and also display good coordination abilities (Choi et al., 2008;Jones et al., 2008;Su et al., 2006). As part of our research on coordination chemistry of thioureas, we are interested in the study of the influence of non-covalent interactions, especially hydrogen bonds and π-π stacking interactions, on the coordination modes of benzothiazoles bearing the 4-nitrobenzoylthiourea group with transition metal ions. Such coordination compounds of thiourea have been studied for various biological systems like antibactrial, antifungal and anticancer activities (Yunus et al., 2008).The importance of such work lies in the possibility that the next generation of thiourea derivatives might be more efficacious as antimicrobial and anticancer agents. However, a thorough investigation relating structure and activity of thiourea derivatives as well as their stability under biological conditions is required. These detailed investigations could be helpful in designing more potent antimicrobial and anticancer agents for therapeutic use. Condensation of acyl or aroyl thiocyanates with primary amines affords 1, 3-disubstituted thioureas in excellent yields in a single step. In the present paper, the crystal structure of the title compound is reported.

Experimental
A mixture of ammonium thiocyanate (0.1 mol) and 4-nitrobenzoyl chloride (0.1 mol) in anhydrous acetone (60 ml) was stirred for 40 min. 2-Aminobenzothiazole (0.1 mol) was added and the reaction mixture was refluxed for 2 h. After cooling, the reaction mixture was poured into 800 ml of acidified cold water (pH = 5). The resulting dark yellow solid was filtered and washed with cold acetone (yield 1.56 g, 87%). The title compound (I) was obtained as suitable crystals for X-ray analysis after recrystallization of the solid from a 1:1 ethanol-dichloromethane mixture.

Refinement
NH H atoms were refined freely. Other H atoms were placed in calculated positions and refined using a riding model with as those based on F, and R-factors based on ALL data will be even larger.