In the title compound, C(17)H(18)N(2)O(4)S, where one of the N-4-methoxy-phenyl fragments is disordered over two sets of sites, the five-membered ring exhibits a nearly half-chair conformation and the two hydroxyl groups lie on opposite sides of the five-membered ring. In the crystal, the mol-ecules are linked into sheets parallel to (100) via O-H⋯O and O-H⋯S hydrogen bonds.