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

Participants

Reaction Steps

To a mixture of the amidine of step 1 (2.0 g, 7.1 mmol) and sodium bicarbonate (1.2 g, 14.3 mmol) in isopropanol (200 ml), 3-bromo-1,1,1-trifluoroacetone 1.1 ml, 10.7 mmol) was added. After heating at 80–85° C. for 16 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 mixture (25.7 g) was purified by chromatography (silica gel, ethyl acetate/hexane 55/45) to give the 4,5-dihydro-imidazole (1.1 g, 38%) as a white solid: mp (DSC) 214° C. Anal. Calcld. for C15H13N2S2O3F3: C, 46.15, H, 3.36, N, 7.18, S, 16.43. Found: C, 46.09, H, 3.26, N, 7.07, S, 16.71.

Provenance & Evidence