In the title compound, C(14)H(14)F(4)N(2)O(3)S, the hexa-hydro-pyrimidine ring adopts a half-chair conformation. The mol-ecular conformation is stabilized by an intra-molecular O-H⋯O hydrogen bond, generating an S(6) ring. The crystal structure features O-H⋯S and N-H⋯S hydrogen bonds.