p-Toluenesulfonic acid monohydrate → 1-(4-Methanesulfonyl-phenyl)-2-p-tolyl-4-trifluoromethyl-1H-imidazole

Participants

Reaction Steps

A mixture of 2-(4-methylphenyl)-4-hydroxy-1-[4-(methylsulfonyl)phenyl]-4-trifluoromethyl-4,5-dihydro-1H-imidazole (Step 2) (0.9 g, 2.3 mmol) and p-toluenesulfonic acid monohydrate (150 mg) in toluene (100 mL) was heated to reflux for 72 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 concentration in vacuo, the crude mixture was purified by chromatography on silica gel using toluene/ethyl acetate (1/1) to give pure 2-(4-methylphenyl)-1-[4-(methylsulfonyl)phenyl]-4-trifluoromethyl-1H-imidazole (462. mg, 54%) as a white solid: mp (DSC) 190° C. Anal. Calc'd for C18H15N2F3SO2: C, 56.84; H, 3.97; N, 7.36; S, 8.43. Found: C, 56.66; H, 3.82; N, 7.23; S, 8.45.

Provenance & Evidence