In the title compound, C20H27N5O3, the central piperazine ring adopts a chair conformation, with the N-bound carboxyl-ate and methyl-ene substituents occupying bis-ectional and equatorial orientations, respectively. A twist is evident between the aromatic rings [dihedral angle = 25.61 (9)°] but an intra-molecular O-H⋯N hydrogen bond persists between these. Supra-molecular tapes along [1-10] are formed in the crystal packing through N(amino)-H⋯O(hydrox-yl) and N(amino)-H⋯N(pyrimidin-yl) hydrogen bonds, and these are linked into layers in the ab plane by π-π inter-actions [inter-centroid distance between pyrimidinyl rings = 3.5919 (9) Å].