In the title compound, C(17)H(19)NO(4)S, the terminal ethyl group is disordered over two sets of sites, with refined site occupancies of 0.536 (7) and 0.464 (7). The dihedral angle between the two aromatic rings is 81.92 (12)°. The mol-ecular conformation is stabilized by intra-molecular N-H⋯O and C-H⋯O hydrogen bonds, which generate S(6) motifs. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds, forming chains along the b axis.