4-Nitro-N′-[(1E,2E)-3-phenylprop-2-en-1-ylidene]benzohydrazide

In the title molecule, C16H13N3O3, the benzene and phenyl rings are linked through a propenylidene hydrazide fragment, C—C(=O)—N(H)—N=C(H)—C(H)=C(H)—, which is fully extended with torsion angles in the range 175.4 (2)–179.9 (2)°. The dihedral angle between the the benzene and phenyl rings is 58.28 (7)°. In the crystal structure, intermolecular N—H⋯O hydrogen bonds link the molecules into chains along the b axis and additional stabilization is provided by weak intermolecular C—H⋯O hydrogen bonds.

In the title molecule, C 16 H 13 N 3 O 3 , the benzene and phenyl rings are linked through a propenylidene hydrazide fragment, C-C( O)-N(H)-N C(H)-C(H) C(H)-, which is fully extended with torsion angles in the range 175.4 (2)-179.9 (2) . The dihedral angle between the the benzene and phenyl rings is 58.28 (7) . In the crystal structure, intermolecular N-HÁ Á ÁO hydrogen bonds link the molecules into chains along the b axis and additional stabilization is provided by weak intermolecular C-HÁ Á ÁO hydrogen bonds.
HLS is grateful to the Institute of Chemistry, University of the Punjab, for financial support.

Structure Reports Online
These have been used as intermediates in the synthesis of oxadiazoles, triazoles and thiadiazoles (Küçükgüzel et al., 2007;et al., 2006;Stocks et al., 2004). Prompted by these observations and in continuation of our studies on the synthesis of various heterocyclic compounds (Ahmad et al., 2010;Zia-ur-Rehman et al., 2009), we herein report the structure of the title compound (I).
In the the title compound ( Fig. 1) the bond distances and angles agree with the corresponding bond distances and angles reported in a closely related compound (Ji & Shi, 2008). The benzene rings in (I) are linked through a propenylidenehydrazide fragment, C1/C7/N2/N3/C8/C9/C10, which is fully extended with torsion angles in the range 175.4 (2) and 179.9 (2)°. The dihedral angle between the two benzene rings is 58.28 (7)°. In the crystal structure, intermolecular N-H···O hydrogen bonds link the molecules into a chain along the b-axis and additional stabilization is provided by weak intermolecular C-H···O hydrogen bonds; details have been provided in Table. 1 and Fig. 2.

Experimental
A mixture of para nitrobenzohydrazide (0.5 g, 2.76 mmoles), cinnamaldehyde (0.348 ml, 2.76 mmoles), orthophosphoric acid (0.2 ml) and methanol (50.0 ml) was refluxed for a period of 2 hours followed by removal of the solvent under vacuum. The contents were cooled and washed with cold methanol followed by crystallization from the same solvent at room temperature by slow evaporation. Yield: 94%. M.p. 516-517 K.

Refinement
Though all the H atoms could be distinguished in the difference Fourier map the H-atoms were included at geometrically idealized positions and refined in riding-model approximation with N-H = 0.88 Å and C-H = 0.95 Å. The U iso (H) were allowed at 1.2U eq (N/C). The final difference map was essentially featurless. Fig. 1. The title molecule with the displacement ellipsoids plotted at 50% probability level (Farrugia, 1997

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.