Ethyl 6-(4-fluorophenyl)-4-hydroxy-2-sulfanylidene-4-trifluoromethyl-1,3-diazinane-5-carboxylate

In the title compound, C14H14F4N2O3S, the hexahydropyrimidine ring adopts a half-chair conformation. The molecular conformation is stabilized by an intramolecular O—H⋯O hydrogen bond, generating an S(6) ring. The crystal structure features O—H⋯S and N—H⋯S hydrogen bonds.

In the title compound, C 14 H 14 F 4 N 2 O 3 S, the hexahydropyrimidine ring adopts a half-chair conformation. The molecular conformation is stabilized by an intramolecular O-HÁ Á ÁO hydrogen bond, generating an S(6) ring. The crystal structure features O-HÁ Á ÁS and N-HÁ Á ÁS hydrogen bonds.
flumioxazin is a widely used herbicide (Konz, 1997;Hass, 2004). This led us to focus our attention on the synthesis and bioactivity of these important fused perfluoroalkylated heterocyclic compounds. During the synthesis of DHPM derivatives, the title compound, an intermediate C 14 H 14 F 4 N 2 O 3 S (I) was isolated and the structure confirmed by X-ray diffraction.
In the structure of the title molecule, the hexahydropyrimidine ring adopts a half-chair conformation, the mean planes formed by the ring atoms excluding the C atom bonded to the ethoxy carbonyl group have r.m.s. deviations of 0.0348 Å, the dihedral angle between the mean planes and benzenes ring is 58.18 (5)
The title compound was recrystallized from 50% aqueous ethanol and single crystals of (I) were obtained by slow evaporation.

Refinement
Hydrogen atoms involved in hydrogen-bonding inetractions were located by difference methods and their positional and isotropic displacement parameters were refined. Other H atoms were placed in calculated positions, with C-H(aromatic) = 0.95 Å and C-H(aliphatic) = 0.98 Å, 0.99 Å or 1.00 Å, and treated as riding, with U iso (H) = 1.2Ueq(C).  Molecular configuration and atom numbering scheme for (I), with displacement ellipsoids drawn at the 30% probability level.

Figure 2
The packing diagram of the title compound. Intermolecular hydrogen bonds are shown as dashed line. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.