The mol-ecule of the title compound, C(21)H(26)N(2)O(6), which lies across a crystallographic inversion centre, crystallizes with two unique half-molecules in the symmetric unit and adopts a linear configuration and the imino group is coplanar with the aromatic ring, making a dihedral angle of 3.26 (3)°. Strong intra-molecular O-H⋯N and weak inter-molecular O-H⋯O and C-H⋯O hydrogen bonds and weak inter-molecular π-π stacking inter-actions [centroid-centroid distance = 4.419 (2) Å]establish an infinite three-dimensional supra-molecular structure.