In the title compound, C(17)H(27)N(3)O(4), the six-membered ring adopts a half-chair conformation with the N atom and the adjacent methyl-ene C atom displaced by -0.391 (2) and 0.358 (2) Å, respectively, from the plane of the other four atoms. In the crystal, mol-ecules are linked by weak C-H⋯O inter-actions.