p-Toluenesulfonic acid monohydrate → 3-[1-(4-Methanesulfonyl-phenyl)-4-trifluoromethyl-1H-imidazol-2-yl]-5-methyl-pyridine

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Reaction Steps

A mixture of 3-methyl-5-[4-hydroxy-1-[4-(methylsulfonyl)phenyl]-4-(trifluoromethyl)-4,5-dihydro-1H-imidazol-2-yl]pyridine from step 4 (3.8 g, 9.5 mmol) and p-toluenesulfonic acid monohydrate (0.91 g, 4.8 mmol) in 150 mL of toluene was heated to reflux for 24 hours. The reaction mixture was cooled and the solvent was removed under reduced pressure. The residue was partitioned between water and methylene chloride. The organic layer was washed with water, saturated sodium bicarbonate solution and brine, dried over magnesium sulfate and filtered. The filtrate was evaporated in vacuo and the crude product was purified by flash chromatography on silica gel (ethyl acetate/acetone, 98:2) to give 3-methyl-5-[1-[4-(methylsulfonyl)phenyl]-4-(trifluoromethyl)-1H-imidazol-2-yl]pyridine as a yellow solid (1.7 g, 47%): mp (DSC) 196-198° C.; Anal. Calc'd. for C17H14F3N3O2S: C, 53.54, H, 3.70, N, 11.02, S, 8.41. Found: C, 53.50, H, 3.65, N, 10.82, S, 8.55.

Provenance & Evidence