rac-Ethyl 4-hy-droxy-4-trifluoro-methyl-6-(2,4,5-trimeth-oxy-phen-yl)-2-thio-1,3-diazinane-5-carboxyl-ate.

In the title compound, C(17)H(21)F(3)N(2)O(6)S, the hexa-hydro-pyrimidine ring adopts a half-chair conformation: the mean plane formed by the ring atoms excluding the C atom bonded to the eth-oxy-carbonyl group has an r.m.s. deviation of 0.0427 Å and forms a dihedral angle of 66.41 (5)° with the benzene ring. The mol-ecular conformation is stabilized by an intra-molecular hydroxyl O-H⋯O(carbox-yl) hydrogen bond, generating an S(6) ring. In the crystal, pairs of N-H⋯S and N-H⋯O hydrogen bonds give rise to the formation of two-dimensional networks lying parallel to the ab plane, which incorporate graph-set motifs R(2) (2)(8) and R(2) (2)(16), respectively.