(E)-4-Amino-N′-(5-chloro-2-hydroxybenzylidene)benzohydrazide

In the title hydrazide Schiff base compound, C14H12ClN3O2, the conformation around the C=N double bond is E. The dihedral angle between the benzene rings is 41.57 (14) Å. An intramolecular O—H⋯N hydrogen bond makes an S(6) ring motif. In the crystal, molecules are linked by N—H⋯O (bifurcated acceptor) and N—H⋯N hydrogen bonds, forming chains along the a axis. The interesting feature of the crystal structure is the short intermolecular C⋯O [3.216 (3), 3.170 (3), and 2.992 (3) Å] contacts, one of which is significantly shorter than the sum of the van der Waals radii of these atoms [3.22 Å].

In the title hydrazide Schiff base compound, C 14 H 12 ClN 3 O 2 , the conformation around the C N double bond is E. The dihedral angle between the benzene rings is 41.57 (14) Å . An intramolecular O-HÁ Á ÁN hydrogen bond makes an S(6) ring motif. In the crystal, molecules are linked by N-HÁ Á ÁO (bifurcated acceptor) and N-HÁ Á ÁN hydrogen bonds, forming chains along the a axis. The interesting feature of the crystal structure is the short intermolecular CÁ Á ÁO [3.216 (3), 3.170 (3), and 2.992 (3) Å ] contacts, one of which is significantly shorter than the sum of the van der Waals radii of these atoms [3.22 Å ].
The title molecule, Fig. 1, has an E conformation around C═N double bond. The bond lengths (Allen et al., 1987) and angles are within normal ranges and are comparable to those reported for related structures (Xu, 2012;Shi & Li, 2012;Bakir & Green, 2002). The dihedral angle between the substituted phenyl rings is 41.57 (14)Å. An intramolecular O-H···N hydrogen bond makes an S(6) ring motif (Bernstein et al., 1995).
In the crystal, molecules are linked through N-H···O (bifurcated acceptor) and N-H···N hydrogen bonds forming onedimensional chains along the a axis. An interesting feature of the crystal structure is the short intermolecular C1···O1 iii is significantly shorter than the sum of the van der Waals radii of these atoms [3.22Å; Bondi, 1964].

Experimental
The title compound was synthesized by adding 1 mmol of methyl 4-aminobenzoate to a solution of 5-chlorosalicylaldehyde (1 mmol) in methanol (30 ml). The mixture was refluxed with stirring for 30 min and after cooling to room temperature a light-yellow precipitate was filtered and washed with diethylether and dried in air. Light-yellow prismatic crystals of the title compound, suitable for X-ray structure analysis, were recrystallized from ethanol by slow evaporation of the solvents at room temperature over several days.

Refinement
The N-bound H atoms were located in a difference Fourier map and were constrained to ride on their parent atoms with U iso (H) = 1.2U eq (N). The OH H atom was positioned by a freely rotating OH group model: O-H = 0.82 Å with U iso (H) = 1.5U eq (O). The C-bound H atoms were included in calculated positions and treated as riding atoms: C-H = 0.93 Å with U iso (H) = 1.2U eq (C).

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.