N′-(3-Hydroxybenzylidene)-4-methylbenzohydrazide

The title compound, C15H14N2O2, was obtained from the reaction of 3-hydroxybenzaldhyde and 4-methylbenzohydrazide in methanol. In the molecule, the benzene rings form a dihedral angle of 2.9 (3)°. In the crystal, N—H⋯O and O—H⋯O hydrogen bonds link the molecules into layers parallel to (101). The crystal packing also exhibits π–π interactions between the aromatic rings [centroid–centroid distance = 3.686 (4) Å].


N′-(3-Hydroxybenzylidene)-4-methylbenzohydrazide
Ji-Lai Liu, Ming-Hui Sun and Jing-Jun Ma Comment Benzohydrazide compounds are well known for their biological activities (El-Sayed et al., 2011;Horiuchi et al., 2009). In addition, benzohydrazide compounds have also been used as versatile ligands in coordination chemistry (El-Dissouky et al., 2010, Zhang et al., 2010. As a contribution to a structural study on hydrazone compounds, we present here the crystal structure of the title compound (I) obtained in the reaction of 3-hydroxybenzaldehyde with 4-methylbenzohydrazide in methanol.

Experimental
To a methanol solution (20 ml) of 3-hydroxybenzaldehyde (0.1 mmol, 12.2 mg) and 4-methylbenzohydrazide (0.1 mmol, 15.0 mg), a few drops of acetic acid were added. The mixture was refluxed for 1 h and then cooled to room temperature.
The white crystalline solid was collected by filtration, washed with cold methanol and dried in air. Single crystals, suitable for X-ray diffraction, were obtained by slow evaporation of a methanol solution of the product in air.

Refinement
The amino H-atom was located in a difference Fourier map and was refined with a distance restraint, N-H = 0.90 (1) Å.

Computing details
Data collection: SMART (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97  The molecular structure of (I), with the numbering scheme and displacement ellipsoids drawn at the 30% probability level. Special details Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s 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.