1-(3-Fluorophenyl)-3-(4-nitrophenyl)urea

In the title compound, C13H10FN3O3, the dihedral angle between the fluorophenyl and nitrophenyl ring planes is 6.51 (9)°. The crystal structure features N—H⋯O hydrogen bonds.

In the title compound, C 13 H 10 FN 3 O 3 , the dihedral angle between the fluorophenyl and nitrophenyl ring planes is 6.51 (9) . The crystal structure features N-HÁ Á ÁO hydrogen bonds.

Related literature
The title compound is an activated fragment of sorafenib derivatives. Sorafenib is a VEGFR-2 inhibitor (Ferrara et al., 2003;Peruzzi et al., 2006) that has good therapeutic effect for renal carcinoma and liver cancer (Wan et al., 2004;Wilhelm et al., 2004).
In the molecule of the title compound ( Fig.1) bond lengths and angles have normal values. The interplanar angle between the fluorobenzyl and nitrobenzyl ring planes is 6.51 (9)°. The crystal structure is stabilized by the intermolecular N-H···O hydrogen bonds. The crystal structure (Fig.2) is stabilized by intermolecular N-H···O hydrogen bonds (table   1).

Experimental
A solution of 4-nitroaniline (1.38 g, 10 mmol) in DCM (100 ml) was added dropwise to a stirred solution of bis(trichloromethyl) carbonate (5.92 g, 20 mmol) in DCM (20 ml) at the atmosphere of ice-bath.The reaction mixture was stirred for 2 hrs at 0-5°C. Then the reaction mixture was added drpwise to a refluxed and stirred solution of 3-fluoroaniline (1.11 g, 10 mmol) in DCM (40 ml).The reaction was completed within 2 hrs at the reflux temperature.The solvent was removed under reduced pressure.Acetone (100 ml) and H 2 O (300 ml) was added to the mixture. The solid was collected and washed with H 2 O,then gave a yellow solid. The yield was 2.08 g (75.6%). Put about 0.3 g of the product in the ampoule bottle and add 10 ml absolute ethyl alcohol, yellow single crystals suitable for X-ray diffraction analysis were obtained by slow evaporation of the solvent at room temperature after 3 weeks.

Refinement
All H atoms were detected in a difference map, nevertheless, the H-atoms attached to the nitrogen atoms were refined freely, and the H-atoms attached to the carbon atoms were placed in calculated positions and refined using a riding motion approximation, with C-H=0.95 Å, with U iso (H)=1.2U eq (C).  The molecular structure of the title compound, showing the atomic numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.

Figure 2
Packing diagram of the title compound viewed along the c axis. Hydrogen bonds are shown as dashed lines.

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.