Iodine → 5-iodo-1-(3-(trifluoromethyl)phenyl)pyrimidin-2,4(1H,3H)-dione

To a suspension of 1-(3-(trifluoromethyl)phenyl)pyrimidin-2,4(1H,3H)-dione (prepared in Reference Example 113) (5.09 g) in acetonitrile (75 ml) were added iodine (3.03 g) and cerium ammonium nitrate (6.54 g) and the resulting mixture was stirred at 80° C. for thirty minutes. The resulting mixture was cooled to 0° C. and thereto were then added ethyl acetate (150 ml), saturated saline (50 ml) and 5% sodium hydrogen sulfite solution (100 ml) so as to separate the layer. Furthermore, the aqueous layer was extracted with ethyl acetate, and the organic layer was washed with 5% aqueous sodium hydrogen sulfite solution and saturated saline. The resulting mixture was dried over anhydrous magnesium sulfate and then concentrated under reduced pressure. To the residue were added ethyl acetate (50 ml) and hexane (100 ml) and the resulting mixture was stirred for fifteen minutes, and the precipitated solids were then collected by filtration and washed with hexane to afford 5-iodo-1-(3-(trifluoromethyl)phenyl)pyrimidin-2,4(1H,3H)-dione (7.34 g).