The title compound, C(16)H(23)NO(4), is essentially planar except for the last two C atoms in each n-butyl group (r.m.s. deviation from the least-squares plane = 0.02 Å for 17 non-H atoms). In the crystal, inter-molecular N-H⋯O hydrogen bonds between the amine and carbonyl groups link the mol-ecules into one-dimensional chains.