In the title compound, C(21)H(19)NO(7)S(2), the dihedral angles between the formyl-phenyl ring and the two meth-oxy-phenyl rings are 33.87 (9) and 41.00 (10)°. The S atoms have a distorted tetra-hedral geometry and the N atom shows a trigonally planar [r.m.s. deviation = 0.0437 (13) Å] coordination. The crystal structure is stabilized by inter-molecular C-H⋯O hydrogen bonds.