N′-(2-Hydroxynaphthylidene)-4-methoxybenzohydrazide

The title Schiff base compound, C19H16N2O3, was derived from the condensation reaction of 2-hydroxy-1-naphthylaldehyde with 4-methoxybenzohydrazide. The dihedral angle between the benzene ring and the naphthyl ring system is 6.8 (2)°. In the crystal structure, molecules are linked through intermolecular N—H⋯O intermolecular hydrogen bonds, forming chains running along the c axis.

The title Schiff base compound, C 19 H 16 N 2 O 3 , was derived from the condensation reaction of 2-hydroxy-1-naphthylaldehyde with 4-methoxybenzohydrazide. The dihedral angle between the benzene ring and the naphthyl ring system is 6.8 (2) . In the crystal structure, molecules are linked through intermolecular N-HÁ Á ÁO intermolecular hydrogen bonds, forming chains running along the c axis.

Related literature
For related structures, see: Tang (2006Tang ( , 2007a. For reference structural data, see: Allen et al. (1987).  Table 1 Hydrogen-bond geometry (Å , ).   Recently, the author has reported the structures of several Schiff base compounds (Tang, 2006(Tang, , 2007a and, in continuation of work in this area, reports herein the structure of the title compound, (I), Fig. 1, a new Schiff base compound.
In the crystal structure of the compound, molecules are linked through N-H···O intermolecular hydrogen bonds (Table   1), forming chains running along the c axis ( Fig. 2).
Experimental 2-Hydroxy-1-naphtylaldehyde (0.1 mmol, 17.2 mg) and 4-methoxybenzohydrazide (0.1 mmol, 16.6 mg) were dissolved in an ethanol solution (20 ml). The mixture was stirred at reflux for 10 min to give a clear colorless solution. Colorless needle-like crystals of the compound were formed by slow evaporation of the solvent over several days.
Figures Fig. 1. The molecular structure of the compound, showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.

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.