(E)-N′-(2-Chloro-5-nitrobenzylidene)-4-methoxybenzohydrazide

In the title compound, C15H12ClN3O4, the benzohydrazide group is not planar and the molecule exists in a trans configuration with respect to the methylidene unit. The dihedral angle between the two substituted benzene rings is 0.4 (3)°. In the crystal structure, molecules are linked by intermolecular N—H⋯O hydrogen bonds, forming chains parallel to the c axis.

In the title compound, C 15 H 12 ClN 3 O 4 , the benzohydrazide group is not planar and the molecule exists in a trans configuration with respect to the methylidene unit. The dihedral angle between the two substituted benzene rings is 0.4 (3) . In the crystal structure, molecules are linked by intermolecular N-HÁ Á ÁO hydrogen bonds, forming chains parallel to the c axis.

Structure Reports Online
In the structure of the title compound ( Fig. 1), the molecule exists in a trans configuration with respect to the methylidene unit. The dihedral angle between the two substituted benzene rings is 0.4 (3)°. In the 2-chloro-5-nitrophenyl unit, the nitro group is slightly twisted from the mean plane of the C1-C6 ring with a dihedral angle of 7.4 (3)°. The same pattern can ben observed in a similar hydrazone compound (Fun, Patil, Rao et al., 2008). In the 4-methoxyphenyl unit, the methoxy group is nearly coplanar with the mean plane of the C9-C14 ring, with atom C15 deviating from the C9-C14 ring by 0.098 (2) Å.
In the crystal structure, molecules are linked by intermolecular N-H···O hydrogen bonds (Table 1), to form chains parallel to the c axis (Fig. 2).

Experimental
The compound was prepared by refluxing 2-chloro-5-nitrobenzaldehyde (1.0 mol) with 4-methoxybenzohydrazide (1.0 mol) in methanol (100 ml). Excess methanol was removed from the mixture by distillation. The colourless solid product was filtered, and washed three times with methanol. Colourless block crystals of the title compound were obtained from a methanol solution by slow evaporation in air.

Refinement
Atom H2 was located in a difference Fourier map and refined isotropically, with the N-H distance restrained to 0.90 (1) Å.
Other H atoms were placed in calculated positions (C-H = 0.93-0.96 Å) and refined as riding with U iso (H) = 1.2 U eq (C) or 1.5U eq (C) for methyl H atoms. A rotating group model was used for the methyl group.

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.