Crystal structure of 2-nitro-N-(5-nitro-1,3-thiazol-2-yl)benzamide

In the title compound, C10H6N4O5S, the mean plane of the non-H atoms of the central amide fragment C—N—C(=O)—C [r.m.s. deviation = 0.0294 Å] forms dihedral angles of 12.48 (7) and 46.66 (9)° with the planes of the thiazole and benzene rings, respectively. In the crystal, molecules are linked by N—H⋯O hydrogen bonds, forming chains along [001]. In addition, weak C—H⋯O hydrogen bonds link these chains, forming a two-dimensional network, containing R 4 4(28) ring motifs parallel to (100).


S1. Comment
The crystal structure determination of the title compound (I), is part of a study of a series of fenilbenzamidas derived from 5-nitro-1,3-thiazole carried out by our research group. Crystal structures of compounds similar to (I), such as 2-hy-  Table 1, Nardelli, 1995). N3-H3···O3 i hydrogen bonds are responsible for hydrogen-bonded chains in the c-axis direction. The N3-H3 group of the amide moiety in the molecule at (x, y, z) acts as a hydrogen-bond donor to O3 atom of the carbonyl group in the molecule at (x, -y+1/2, z-1/2). In addition, weak hydrogen bonds C9-H9···O2 ii , form chains in the b-axis direction. The C9-H9 group of the benzene ring in the molecule at (x, y, z) acts as a hydrogen bond donor to atom O2 in the molecule at (x, y-1, z). It is possible that for this weak hydrogen bond to occur, a rotation of the benzene ring with respect to plane formed by the central amide moiety is required. The combination of the above hydrogen bond interactions generate edge-fused R 4 4 (28) rings.

S2. Experimental
The reagents and solvents for the synthesis were obtained from the Aldrich Chemical Co., and were used without additional purification. The title molecule was synthesized using equimolar amounts of 2-nitrobenzoyl chloride (0.171g, 0.923mmol) and 5-nitro-1,3-thiazole (0.134g). The reagents were dissolved in 7 mL of acetonitrile and the solution was refluxed with constant stirring for 4 hours. A after evaporation of the solvent a brown solid was obtained. The solid was washed with distilled water to remove impurities. Pale-brown crystals of good quality [m.p. 515 (1)K] suitable for singlecrystal X-ray diffraction were grown from a solution of the title compound in acetonitrile.

S3. Refinement
All H atoms were positioned in geometrically idealized positions, with C-H = 0.93 Å and N-H = 0.86 Å, and were refined using a riding-model approximation, with U iso (H) constrained to 1.2 times U eq of the respective parent atom.

Figure 1
The molecular structure of (I) with displacement ellipsoids drawn at the 50% probability level. H atoms are shown as spheres of arbitrary radius.

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 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.