In the title compound, C(16)H(21)N(3)O(3), the piperazine ring adopts a chair conformation, with its N-C bonds in pseudo-equatorial orientations. In the crystal, mol-ecules are linked by O-H⋯N hydrogen bonds, generating C(5) chains propagating in [101]. Weak aromatic π-π stacking inter-actions also occur [centroid-centroid separation = 3.899 (1) Å].