Triethylborane → 4-[2-(4-chlorophenyl)-4-(trifluoromethyl)-1H-imidazol-1-yl]benzenesulfonamide

Participants

Reaction Conditions

Reaction Steps

To a clear solution of 2-(4-chlorophenyl)-1-[4-(methylsulfonyl)phenyl]-4-(trifluoromethyl)-1H-imidazole from Example 2 (400 mg, 1 mmol) in tetrahydrofuran (THF) (8 mL) at 0° C., n-BuMgCl (2M solution in THF, 2 mL, 4 mmol) was added over 10 minutes. After stirring for additional 10 minutes, ice bath was removed and solution stirred for 1 hour. The reaction mixture was re-cooled to 0° C. and triethylborane (1M solution in THF, 5 mL, 5 mmol) was added. After stirring for 2 hours, the reaction was heated to reflux for 48 hours. The reaction mixture was cooled to room temperature and treated with aqueous sodium acetate (1 g in 4 mL water). After stirring for 5 minutes, solid hydroxylamine-O-sulfonic acid (1 g) was added and the mixture stirred for 20 hours. The reaction mixture was diluted with water and extracted with ether (2×250).The ethereal layer was dried over sodium sulfate, filtered and concentrated in vacuo. The crude solid (568 mg) was chromatographed [silica gel, ethyl acetate/toluene (3/7)] to give 4-[2-(4-chlorophenyl)-4-(trifluoromethyl)-1H-imidazol-1-yl]benzenesulfonamide (260 mg, 65%): mp (DSC) 225° C.

Provenance & Evidence