2-Hydr­oxy-N′-(2-hydr­oxy-4-methoxy­benzyl­idene)-3-methyl­benzohydrazide monohydrate

In the title compound, C(16)H(16)N(2)O(4)·H(2)O, the dihedral angle between the two benzene rings is 12.4 (2)° and the mol­ecule adopts an E configuration with respect to the C=N bond. There are intra­molecular O—H⋯N and O—H⋯O hydrogen bonds in the hydrazone mol­ecule, which both generate S(6) rings. In the crystal structure, mol­ecules are linked by N—H⋯O and O—H⋯O hydrogen bonds, forming layers parallel to the ab plane. The crystal studied was a non-merohedral twin with a domain ratio of 0.887 (3):0.113 (3).