In the title compound, C(6)H(12)N(2)O(2)S, the heterocyclic ring has a sofa conformation. The mol-ecular conformation is stabilized by an intra-molecular O-H⋯O hydrogen-bond inter-action with graph-set motif S(6). In the crystal, mol-ecules are linked by O-H⋯S, N-H⋯S and N-H⋯O hydrogen-bond inter-actions, forming an extended two-dimensional framework parallel to the ac plane.