4-Hydroxy-3,5-dimethoxybenzaldehyde isonicotinoylhydrazone monohydrate.

In the title compound, C15H15N3O4·H2O, the organic molecule exists in the keto–imine tautomeric form. The benzene ring makes a dihedral angle of 49.9 (2)° with the pyridine ring. The molecules pack in a three-dimensional framework structure by a combination of O—H...O, O—H...N, N—H...O and N—H...N hydrogen bonds. The water molecule of hydration is disordered [ratio of components 0.758 (7):0.242 (7)]. [ABSTRACT FROM AUTHOR]