1-(Adamantan-1-ylcarbonyl)-3-(2,6-difluoro-4-hydroxyphenyl)thiourea

In the title molecule, C18H20F2N2O2S, the 2,6-difluoro-4-hydroxyphenyl ring and the carbonylthiourea group are each essentially planar, with maximum deviations of atoms from their mean planes of 0.0113 (14) and 0.1017 (15) Å, respectively; the dihedral angle between these two planes is 71.03 (6)°. An intramolecular N—H⋯O hydrogen bond occurs. In the crystal, N—H⋯O and O—H⋯S hydrogen bonds connect the molecules into chains running diagonally across the bc plane. C—H⋯S and C—H⋯F contacts are also observed.

In the title molecule, C 18 H 20 F 2 N 2 O 2 S, the 2,6-difluoro-4hydroxyphenyl ring and the carbonylthiourea group are each essentially planar, with maximum deviations of atoms from their mean planes of 0.0113 (14) and 0.1017 (15) Å , respectively; the dihedral angle between these two planes is 71.03 (6) . An intramolecular N-HÁ Á ÁO hydrogen bond occurs. In the crystal, N-HÁ Á ÁO and O-HÁ Á ÁS hydrogen bonds connect the molecules into chains running diagonally across the bc plane. C-HÁ Á ÁS and C-HÁ Á ÁF contacts are also observed.
SS is thankful to the University of Hong Kong for providing the facility for crystallographic studies.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: PV2537). In continuation of our studies on structural chemistry of N,N′-disubstituted thiourea (Saeed, et al., 2011), the structure of the title compound is described in this article.
Hydrogen bonding interactions were observed in the crystal lattice which connect the molecules into 1-D chains running diagonally across the b-c-plane (Table 1 and Fig. 2).

Experimental
A mixture of adamantane-1-carbonyl chloride (199 mg, 1 mmol), 4-amino-3,5-difluorophenol (145 mg, 1 mmol) and potassium thiocyanate (100 mg) was heated for 30 minutes in ethanol (5 ml) at 351 K. The reaction mixture was left overnight to cool down at room temperature to afford a solid product which was filtered off, washed and recrystallized from ethanol. Colorless crystals suitable for X-ray crystallographic studies were collected and dried (yield = 82%; m. p. =

Refinement
The C-bound H atoms were placed at geometrically idealized positions with C-H = 0.93, 0.97 and 0.98 Å for phenyl, methylene and methine H-atoms, respectively, and were refined using riding model with U iso (H) = 1.2U eq (C). The N and O-bound H atoms were located from a difference Fourier map and were refined isotropically.

Figure 2
A view of the N-H···O and O-H···S hydrogen bonds (dotted lines) in the crystal structure of the title compound. H atoms non-participating in hydrogen-bonding were omitted for clarity.

Special details
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq S1 0.98449 (8