2-Hydroxy-N′-[(E)-(3-hydroxy-2-naphthyl)methylene]benzohydrazide

In the title molecule, C18H14N2O3, O—H⋯N and N—H⋯O hydrogen bonds influence the molecular conformation; the benzene and naphthalene planes are inclined at a dihedral angle of 11.54 (5)°. In the crystal structure, intermolecular O—H⋯O hydrogen bonds link the molecules into chains running in the [01] direction.

In the title molecule, C 18 H 14 N 2 O 3 , O-HÁ Á ÁN and N-HÁ Á ÁO hydrogen bonds influence the molecular conformation; the benzene and naphthalene planes are inclined at a dihedral angle of 11.54 (5) . In the crystal structure, intermolecular O-HÁ Á ÁO hydrogen bonds link the molecules into chains running in the [011] direction.
In (I) (Fig. 1), the bond lengths and angles are normal and comparable to those observed in the reported compound (Luo, 2007). In the crystal structure, the C8=N2 bond length is 1.279 (5) Å showing the double-bond character. The dihedral angle between the naphthalene ring and C8/N2/N1 is 10.14 (3) Å, the C1/N1/N2 and benzene ring form a dihedral angle of 6.70 (4) Å showing that intramolecular O-H···N and N-H···O hydrogen bonds (Table 1) influence the molecular conformation.

Experimental
Salicyloyl hydrazide (0.5 mmol) and freshly 2-hydroxyl naphthaldehyde (0.5 mmol) were mixed in 50 ml flash. After stirring 30 min at 353 K, the mixture then cooling slowly to room temperature and affording the title compound, then recrystallized from ethanol, affording the title compound as a green crystalline solid. Elemental analysis: calculated for C 18 H 14 N 2 O 3 : C 70.58, H 4.61, N 9.15%; found: C 70.53, H 4.55, N 9.24%.

Refinement
All H atoms were placed in geometrically idealized positions (N-H 0.86, O-H 0.82 and C-H=0.93 Å) and treated as riding, with U iso (H) = 1.2 U eq of the parent atom. In the absence of any significant anomalous scatterers in the molecule, the 1353 Friedel pairs were merged before the final refinement. Fig. 1. ORTEP drawing of the title molecule with atomic numbering scheme and displacement ellipsoids at 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 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.