N′-(3,5-Dibromo-2-hydroxybenzylidene)-4-nitrobenzohydrazide methanol monosolvate

The title compound, C14H9Br2N3O4·CH4O, was obtained as the product of the reaction of 3,5-dibromosalicylaldehyde with 4-nitrobenzohydrazide in methanol. The benzohydrazide molecule is nearly planar, with a maximum deviation of 0.126 (2) Å. The mean planes of the two benzene rings make a dihedral angle of 9.3 (3)°. Intramolecular O—H⋯N and O—H⋯Br interactions are observed in the benzohydrazide molecule. In the crystal, pairs of adjacent benzohydrazide molecules are linked by two methanol molecules through intermolecular O—H⋯O and N—H⋯O hydrogen bonds, forming a dimer.

The title compound, C 14 H 9 Br 2 N 3 O 4 ÁCH 4 O, was obtained as the product of the reaction of 3,5-dibromosalicylaldehyde with 4-nitrobenzohydrazide in methanol. The benzohydrazide molecule is nearly planar, with a maximum deviation of 0.126 (2) Å . The mean planes of the two benzene rings make a dihedral angle of 9.3 (3) . Intramolecular O-HÁ Á ÁN and O-HÁ Á ÁBr interactions are observed in the benzohydrazide molecule. In the crystal, pairs of adjacent benzohydrazide molecules are linked by two methanol molecules through intermolecular O-HÁ Á ÁO and N-HÁ Á ÁO hydrogen bonds, forming a dimer.
In addition, benzohydrazide compounds have also been used as versatile ligands in coordination chemistry (El-Dissouky et al., 2010). As a contribution to a structural study on hydrazone compounds, we present here the crystal structure of the title compound.
The compound contains a benzohydrazide molecule and a methanol molecule, as shown in Fig. 1. The bond distances and angles are within normal ranges (Allen et al., 1987) and are agree well with the corresponding bond distances and angles reported in closely related compounds (Suleiman Gwaram et al., 2010;Dai & Mao, 2010;Ban, 2010). The benzohydrazide molecule is nearly planar, with a maximum deviation of 0.126 (2) Å. The mean planes of the two benzene rings make a dihedral angle of 9.3 (3)°.
In the crystal structure of the title compound, the adjacent two benzohydrazide molecules are linked by two methanol molecules through intermolecular O-H···O and N-H···O hydrogen bonds, to form a dimer (Table 1, Fig. 2).

Experimental
To a methanol solution (20 ml) of 3,5-dibromosalicylaldehyde (0.1 mmol, 28.0 mg) and 4-nitrobenzohydrazide (0.1 mmol, 18.1 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
H2 atoms bonded to N2 was located in a difference map and refined with distance restraint to 0.90 (1) Å. Other H atoms were positioned geometrically and refined using a riding model, with C-H = 0.93-0.96 Å and with U iso (H) = 1.2U eq (C) and 1.5U eq (O and C15).