4-(3-Fluorophenyl)-6-hydroxy-5-(thiophen-2-ylcarbonyl)-6-trifluoromethyl-1,3-diazinan-2-one

In the title compound, C16H12F4N2O3S, the pyrimidine ring adopts a half-chair conformation; the mean plane formed by the ring atoms excluding the C atom bonded to the thiophen-2-ylcarbonyl group has an r.m.s. deviation of 0.059 Å. The dihedral angle between the benzene and thiophene rings is 62.26 (7)°. The molecular conformation is stabilized by an intramolecular O—H⋯O hydrogen bond, generating an S(6) ring. In the crystal, adjacent molecules are connected via a centrosymmetric R 2 2(6) motif, formed by N—H⋯O hydrogen bonds.

In the title compound, C 16 H 12 F 4 N 2 O 3 S, the pyrimidine ring adopts a half-chair conformation; the mean plane formed by the ring atoms excluding the C atom bonded to the thiophen-2-ylcarbonyl group has an r.m.s. deviation of 0.059 Å . The dihedral angle between the benzene and thiophene rings is 62.26 (7) . The molecular conformation is stabilized by an intramolecular O-HÁ Á ÁO hydrogen bond, generating an S(6) ring. In the crystal, adjacent molecules are connected via a centrosymmetric R 2 2 (6) motif, formed by N-HÁ Á ÁO hydrogen bonds.   Table 1 Hydrogen-bond geometry (Å , ).  Comment Dihydropyrimidine (DHPM) derivatives can be used as potential calcium channel blockers (Zorkun et al., 2006), inhibitors of mitotic kinesin Eg5 for treating cancer (Cochran et al., 2005) and as TRPA1 modulators for treating pain (Moran et al., 2007). In addition, compounds that contain fluorine have special bioactivity, e.g. flumioxazin is a widely used herbicide (Hermann et al., 2003;Ulrich, 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 16 H 12 F 4 N 2 O 3 S (I) was isolated and the structure confirmed by X-ray diffraction.

Related literature
In the structure of the title compound, the dihydropyrimidine ring adopts a half-chair conformation with the C7/C8/C9/ N1/N2 are nearly coplanar. The dihedral angle is 53.77 (5) ° between the dihydropyrimidine rings and the phenyl rings, and 80.57 (6) ° between the dihydropyrimidine rings and thiophene rings, respectively. The dihedral angle between the phenyl rings and thiophene rings is 62.26 (7) °. The molecular conformation is stabilized by intramolecular O-H···O hydrogen bond, generating an S(6) ring. In the crystal, adjacent molecules are connected via a centrosymmetric R 2 2 (6) motif, formed by N-H···O hydrogen bonds. For a crystal structure related to the title compound, see: Mosslemin et al., 2009.

Refinement
Hydrogen atoms involved in hydrogen-bonding interactions 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) = 1.00 Å, and treated as riding, with U iso (H) = 1.2Ueq(C).
supplementary materials sup-2 Figures Fig. 1. Molecular configuration and atom numbering scheme for (I), with displacement ellipsoids drawn at the 50% probability level.
Hall symbol: -P 1 Mo Kα radiation, λ = 0.71073 Å a = 6.6032 (10)  as those based on F, and R-factors based on ALL data will be even larger.