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

Participants

Reaction Steps

To a mixture of 4-chloro-N-[4-(methylsulfonyl)phenyl]benzenecarboximidamide from Step 1 (8 g, 26 mmol) and sodium bicarbonate (4.36 g, 52 mmol) in isopropanol (240 mL), 3-bromo-1,1,1-trifluoroacetone (5.4 mL, 52 mmol) was added. After heating the reaction mixture at 75°-80° C. for 24 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 product (16.2 g) was chromatographed (silica gel, hexane/ethyl acetate, 55/45) to give pure 2-(4-chlorophenyl)-4-hydroxy-1-[4-(methylsulfonyl)phenyl]-4-(trifluoromethyl)-4,5-dihydro-1H-imidazole (6.7 g, 62%) as a white solid: Anal. Calc'd. for C17H14N2SO3ClF3 : C, 48.75, H, 3.37, N, 6.69. Found: C, 48.56, H, 3.22, N, 6.51.

Provenance & Evidence