Triethylborane → 4-[2-(6-Methyl-pyridin-3-yl)-4-trifluoromethyl-imidazol-1-yl]-benzenesulfonamide

Participants

Reaction Steps

To a clear solution of Example 31 (2.4 g, 6.3 mmol) in tetrahydrofuran (60 ml) at 0° C., n-BuMgCl (2M solution in THF, 15.7 ml, 31.5 mmol) was added over 10 minutes. After stirring for additional 20 minutes, the ice bath was removed and the solution was stirred for 2 hours. The reaction mixture was recooled to 0° C. and triethylborane (1M solution in THF, 38 ml, 38 mmol) was added. After stirring for 1 hour, the reaction was heated to reflux for 72 hours. The reaction mixture was cooled to room temperature and treated with aqueous sodium acetate (5.5 g in 22 ml water). After stirring for 5 minutes, solid hydroxylamine-O-sulfonic acid (5.5 g) was added and the mixture stirred for 24 hours. The reaction mixture was diluted with water and extracted with ether. The ethereal layer was dried over sodium sulfate, filtered and concentrated. The crude solid (13.3 g) was purified by chromatography (silica gel, hexane/isopropanol, 7/3) to give 4-[2-(6-methylpyridin-3-yl)-4-(trifluoromethyl)-1H-imidazol-1-yl]benzenesulfonamide (298 mg, 12%): mp (DSC) 203° C. Anal. Calc'd. for C16H13N4SO2F3.0.25 H2O: C, 49.68, H, 3.52 N, 14.48, S, 8.29. Found: C, 49.88, H, 3.39, N, 13.94, S, 8.47.

Provenance & Evidence