Triethylborane → 4-[2-(3-Chloro-4-methyl-phenyl)-4-trifluoromethyl-imidazol-1-yl]-benzenesulfonamide

Participants

Reaction Conditions

Reaction Steps

To a clear solution of 2-(3-chloro-4-methylphenyl)-1-[4-(methylsulfonyl)phenyl]-4-(trifluoromethyl)-1H-imidazole (Example 16) (500 mg, 1.2 mmol) in tetrahydrofuran (10 mL) at 0° C., n-BuMgCl (2M solution in THF, 2.4 mL, 4.8 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, 6 ML, 6 mmol) was added. After stirring for 2 hours, the reaction was heated to reflux for 72 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 product (710 mg) was purified by chromatography (silica gel, ethyl acetate/toluene 3/7) to give pure 4-[2-(3-chloro-4-methylphenyl)-4-(trifluoromethyl)-1H-imidazol-1-yl]benzenesulfonamide (180 mg, 36%) as a white solid: mp (DSC) 222° C. Anal. Calc'd. for C17H13N3SO2F3Cl: C, 49.10; H, 3.15; N, 10.11. Found: C, 49.42; H, 3.19; N, 9.75.

Provenance & Evidence