The mol-ecule of the title compound, C(14)H(11)N(3)O(4), assumes an E conformation about the C=N double bond. The benzene rings form a dihedral angle of 3.9 (2)°. The crystal structure is stabilized by N-H⋯O, O-H⋯N, O-H⋯O and C-H⋯O hydrogen bonds, forming layers parallel to (101). In addition, intra-layer π-π stacking inter-actions [centroid-centroid distance = 3.635 (2) Å] are observed.