3,4,5-Trihydroxybenzohydrazide

In the title compound, C7H8N2O4, the dihedral angle between the aromatic ring and the hydrazide grouping is 21.34 (7)°. In the crystal, the molecules are linked into a three-dimensional network by O—H⋯O, O—H⋯N and N—H⋯O hydrogen bonds.

In the title compound, C 7 H 8 N 2 O 4 , the dihedral angle between the aromatic ring and the hydrazide grouping is 21.34 (7) . In the crystal, the molecules are linked into a three-dimensional network by O-HÁ Á ÁO, O-HÁ Á ÁN and N-HÁ Á ÁO hydrogen bonds.

Comment
In order to further explore the biological significance of hydrazides, we have prepared the title compound (I). It was found to be active against DPPH radical scavenging activity and inactive against all fungal strains (Maqsood et al. 2006). The crystal structures of trimethoxybenzohydrazide (Saeed et al. 2008, Zareef et al. 2006 and para hydroxybenzohydrazide (Jamal et al. 2009) analogues of (I) have already been reported.

Experimental
To a solution of methyl-3,4,5-trihydroxybenzoate (3.68 g, 20 mmol) in 75 ml ethanol, hydrazine hydrate (5.0 ml, 100 mmol) was added. The mixture was refluxed for 5 h and a solid was obtained upon removal of the solvent by rotary evaporation.
Colourless blocks of (I) were grown from a solution of methanol by slow evaporation at room temperature.

Refinement
The H atoms on the N atoms (N-H= 0.92 (2) Fig. 1. The molecular structure of (I) with displacement ellipsoids drawn at 50% probability level.  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.