3-Bromo-1,1,1-trifluoro-2-propanone → 2-Methyl-5-[4-hydroxy-1-[4-(methylsulfonyl)phenyl]-4-(trifluoromethyl)-4,5-dihydro-1h-imidazol-2-yl]pyridine

Participants

Reaction Steps

To a mixture of the amidine of Step 1 (9.8 g, 33.9 mmol) and sodium bicarbonate (5.7 g, 67.8 mmol) in isopropanol (700 ml), 3-bromo-1,1,1-trifluoroacetone (5.3 ml, 50.8 mmol) was added. After heating at 80–85° C. for 24 hours, the reaction mixture was cooled and filtered. The residue was washed with methylene chloride and the combined organic fractions were dried over sodium sulfate, filtered and concentrated. The crude material (25.7 g) was purified by chromatography (silica gel, ethyl acetate/acetone, 98/2) to give 2-methyl-5-[4-hydroxy-1-[4-(methylsulfonyl)phenyl]-4-(trifluoromethyl)-4,5-dihydro-1H-imidazol-2-yl]pyridine (6.3 g, 46%) as a white solid: Anal. Calc'd. for C17H16N3SO3F3: C, 50.55; H, 4.12; N, 10.40. Found: C, 50.51; H, 3.91; N, 10.25.

Provenance & Evidence