2'-(3-Hydroxy-benzyl-idene)pyrazine-2-carbohydrazide monohydrate.

The title compound, C(12)H(10)N(4)O(2)·H(2)O, was synthesized by the reaction of pyrazine-2-carboxylic acid hydrazide and 3-hydroxy-benzaldehyde in ethanol. In the crystal structure, the organic mol-ecules are linked into extended chains by inter-molecular N(amide)-H⋯O(hydr-oxy) hydrogen bonds. Additional hydrogen bonds between the water mol-ecule and three adjacent organic mol-ecules, as well as face-to-face π-π stacking inter-actions between the benzene and pyrazine rings [centroid-to-centroid separation = 3.669 (2) Å and offset = 1.362 Å], link the mol-ecules into a three-dimensional framework.