9-Chloro-6-[1-(difluoromethoxy)-2,2,2-trifluoroethyl]-1-(2-methoxy-4,6-dimethylpyrimidin-5-yl)-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazole → 6-[1-(Difluoromethoxy)-2,2,2-trifluoroethyl]-1-(2-methoxy-4,6-dimethylpyrimidin-5-yl)-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazole

To a solution of 9-chloro-6-[1-(difluoromethoxy)-2,2,2-trifluoroethyl]-1-(2-methoxy-4,6-dimethylpyrimidin-5-yl)-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazole (783 mg, 1.59 mmol) in acetic acid (8.0 mL) was added 10% palladium on carbon (50% wet, 78.3 mg), and the mixture was purged with hydrogen and stirred under balloon pressure hydrogen at room temperature for 2 days. The catalyst was removed by filtration, and the filtrate was concentrated in vacuo. The residue was diluted with saturated aqueous sodium hydrogen carbonate and extracted with ethyl acetate. The combined organic layer was washed with brine, dried over anhydrous magnesium sulfate, filtered and concentrated in vacuo. The residue was purified by flash column chromatography on silica gel eluting with a 75-100% ethyl acetate/n-hexane gradient mixture. The filtrate was concentrated in vacuo to give a solid, which was washed with ethyl acetate/diisopropyl ether to give the title compound as a colorless powder (507 mg, 1.11 mmol, 70%)