N′-(5-Chloro-2-hydroxybenzylidene)-4-hydroxybenzohydrazide

The title Schiff base compound, C14H11ClN2O3, was prepared by the reaction of 5-chlorosalicylaldehyde and 4-hydroxybenzohydrazide. The molecule exists in a trans configuration with respect to the methylidene group. The dihedral angle between the two benzene rings is 40.1 (2)°. An intramolecular O—H⋯N hydrogen bond helps to stabilize the molecular conformation. In the crystal structure, molecules are linked into a three-dimensional network by intermolecular N—H⋯O and O—H⋯O hydrogen bonds.

The title Schiff base compound, C 14 H 11 ClN 2 O 3 , was prepared by the reaction of 5-chlorosalicylaldehyde and 4-hydroxybenzohydrazide. The molecule exists in a trans configuration with respect to the methylidene group. The dihedral angle between the two benzene rings is 40.1 (2) . An intramolecular O-HÁ Á ÁN hydrogen bond helps to stabilize the molecular conformation. In the crystal structure, molecules are linked into a three-dimensional network by intermolecular N-HÁ Á ÁO and O-HÁ Á ÁO hydrogen bonds.
The author acknowledges the Natural Science Foundation of the Education Office of Anhui Province (Project No. 2009 A150020).
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: SJ2605).
The molecule in (I) exists in a trans configuration with respect to the methylidene group. The dihedral angle between the two benzene rings is 40.1 (2)°. The bond lengths in (I) are found to have normal values (Allen et al., 1987) and are comparable to the values found in similar compounds (Singh et al., 2007;Narayana et al., 2007;Cui et al., 2007;Diao et al., 2008). (Table 1) helps to stabilize the molecular conformation. In the crystal structure, molecules are linked into a three-dimensional network by intermolecular N-H···O and O-H···O hydrogen bonds (Table   1 and Fig. 2).

Experimental
The title compound was prepared by the Schiff base condensation of equimolar amounts (0.5 mmol each) of 5-chlorosalicylaldehyde and 4-hydroxybenzohydrazide in methanol (20 ml). Excess methanol was removed from the reaction mixture by distillation. The colourless solid was filtered and dried in air. Colourless block-shaped crystals suitable for X-ray diffraction were obtained from a methanol solution.