p-Toluenesulfonic acid monohydrate → 1-[4-(Methylsulfonyl)phenyl]-2-(4-chlorophenyl)-4-(trifluoromethyl)-1H-imidazole

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Reaction Steps

A mixture of 2-(4-chlorophenyl)-4-hydroxy-1-[4-(methylsulfonyl)phenyl]-4-(trifluoromethyl)-4,5-dihydro-1H-imidazole from Example 1 (6.2 g, 15.4 mmol) and p-toluenesulfonic acid monohydrate (0.9 g, 4.7 mmol) in toluene (300 mL) was heated to reflux for 84 hours. The reaction mixture was cooled and the solvent removed under reduced pressure. The crude residue was redissolved in methylene chloride and washed with water, aqueous sodium bicarbonate and brine. After drying (Na2SO4), filtration and concentrating in vacuo, the crude mixture was purified by chromatography on silica gel using hexane/ethyl acetate (1/1) to give pure 2-(4-chlorophenyl)-1-[4-(methylsulfonyl)phenyl]-4-(trifluoromethyl)-1H-imidazole (4.21 g, 71%) as a white solid: mp (DSC) 183° C. Anal. Calc'd. for C17H12N2SO2F3Cl: C, 50.94, H, 3.02, N, 6.99. Found: C, 50.64, H, 3.03, N, 6.85.

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