1,5-Bis(2-hydroxy-3-methoxybenzylidene)carbonohydrazide methanol 0.47-solvate

In the title compound, C17H18N4O5·0.47CH3OH, the virtually planar (r.m.s. deviation = 0.128 Å) carbonohydrazide molecule is located on a twofold axis and conformation of its C=N bonds is E. There are short intramolecular O—H⋯N hydrogen bonds between the hydroxy groups and hydrazide N atoms. In the crystal, bifurcated N—H⋯(O,O) hydrogen bonds assemble the carbonohydrazide molecules into a three-dimensional network. There are C 2 symmetric voids in this network, 47% of which are occupied by disordered methanol molecules.

In the title compound, C 17 H 18 N 4 O 5 Á0.47CH 3 OH, the virtually planar (r.m.s. deviation = 0.128 Å ) carbonohydrazide molecule is located on a twofold axis and conformation of its C N bonds is E. There are short intramolecular O-HÁ Á ÁN hydrogen bonds between the hydroxy groups and hydrazide N atoms. In the crystal, bifurcated N-HÁ Á Á(O,O) hydrogen bonds assemble the carbonohydrazide molecules into a threedimensional network. There are C 2 symmetric voids in this network, 47% of which are occupied by disordered methanol molecules.
Supporting information for this paper is available from the IUCr electronic archives (Reference: GK2603).

Comment
Carbonohydrazide derivatives give rise to a large spectrum of biological properties such as antioxidant (El-Gammal et al., 2012) and anticancer activities (Bacchi et al., 1999). We report here the crystal structure of the title compound synthesized according to literature (He et al., 2010;Du et al., 2010). All parameters are within normal ranges and comparable with the related structures (Kong et al., 2010).
The molecular structure of the title compound is shown in Fig. 1. The complete carbonohydrazide molecule is generated by a twofold crystallographic axis passing throuth the atoms C8 and O2. A three-center O···(N)H···O intermolecular hydrogen bond involving the amido H atoms and the phenoxo and methoxy O atoms is observed (Fig. 2). There are voids in a three dimensional network containing solvent methanol molecules. Only one methanol molecule can be accommodated in a small void that has C 2 symmetry. This leads to disorder of methanol molecules. In addition refinement of occupancy factors of methanol O and C atoms converged at 0.234 (1), indicating that 47% of voids are occupied by the solvent.

Experimental
In a round bottomed flask, carbonohydrazide (1.0 g, 11.11 mmol) was introduced with methanol (10 ml). o-Vanillin (3.3 g, 22.22 mmol) dissolved in 10 ml of the same solvent was added. Two drops of glacial acetic acid were added while stirring. After one hour under reflux, the precipitate formed that after cooling to room temperature was filtered off and washed with cold methanol. The resulting solid was dried in air. The filtrate was left at room temperature. Slow evaporation of the solvent gave colorless crystals after one day. Yield: 95%; m.p. 378 K. Anal. Calc. for [C 17 H 18

Refinement
H atoms of the NH and OH groups were located in the Fourier difference maps and refined without restraints. Otherg H atoms were geometrically optimized and refined as riding on their carriers with U iso (H) = 1.2U eq (C)(1.5 for CH 3 groups).
Considerable disorder was detected for the solvent methanol molecule. The occupancy factor of the C and O atoms of methanol refined at 0.234 (1). Thus, there are 0.46 methanol molecules per one carbonohydrazide molecule in the crystal.
Owing to a negligible anomalous dispersion effect the Friedel pairs were merged and the absolute structure was not determined.  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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq Occ. (