3-Bromo-1,1,1-trifluoro-2-propanone → 4-hydroxy-1-[4-(methylsulfonyl)phenyl]-2-phenyl-4-trifluoromethyl-4,5-dihydro-1H-imidazole

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Reaction Steps

To a mixture of N-[4-(methylsulfonyl)phenyl]benzenecarboximidamide (Step 1) (16.5 g, 60.1 mmol) and sodium bicarbonate (10.1 g, 0.12 mol) in isopropanol (900 mL), 3-bromo-1,1,1-trifluoroacetone (8.7 ml, 84 mmol) was added. After heating the reaction mixture at 75–80° C. for 20 hours, the solvent was removed. The residue was redissolved in methylene chloride and washed with water. The organic fractions were combined, dried over sodium sulfate, filtered and concentrated in vacuo. The crude mixture was purified by chromatography (silica gel, hexane/ethyl acetate, 45/55) to give 4-hydroxy-1-[4-(methylsulfonyl)phenyl]-2-phenyl-4-trifluoromethyl-4,5-dihydro-1H-imidazole (13.6 g, 59%) as awhite solid: mp 189–190° C. Anal. Calc'd for C17H15N2F3SO3: C, 53.12; H, 3.93; N, 7.29; S, 8.34. Found: C, 53.05; H, 3.90; N, 7.14; S, 8.38.

Provenance & Evidence