hydroxylamine-O-sulfonic acid → 4-(2-Pyridin-3-yl-4-trifluoromethyl-imidazol-1-yl)-benzenesulfonamide

Participants

Reaction Steps

3-[1-[4-[[2-(Trimethylsilyl)ethyl]sulfonyl]phenyl]-4-(trifluoromethyl)-1H-imidazol-2-yl]pyridine was prepared with the product of Example 28 with a method similar to that described in Example 45, Step 1. To a solution of 3-[1-[4-[[2-(trimethylsilyl)ethyl]sulfonyl]phenyl]-4-(trifluoromethyl)-1H-imidazol-2-yl]pyridine (0.200 g, 0.46 mmol) in 1.0 mL of dry THF was added n-Bu4NF (1.38 mL of 1.0 M THF solution, 1.38 mmol). The mixture was heated to reflux for 1 hour and cooled to room temperature. A solution of sodium acetate (0.17 g, 2.1 mmol) in 3 mL of water and hydroxylamine-O-sulfonic acid (0.26 g, 2.3 mmol) were added sequentially and the mixture was stirred for 1 hour. Water (7 mL) and ethyl acetate (7 mL) were added. The organic phase was separated and washed with saturated NaHCO3 solution, water, brine, dried over MgSO4 and filtered. The filtrate was concentrated and the residue was purified by chromatography on silica gel (ethyl acetate/acetone, 95:5) to give 0.147 g of 4-[2-(pyridin-3-yl)-4-(trifluoromethyl)-1H-imidazol-1-yl]benzenesulfonamide as a colorless solid (87%): mp(DSC) 213–215° C. Anal. Calc'd. for C15H11F3N4O2S: C, 48.91; H. 3.01; N, 15.21; S, 8.71. Found: C, 48.58; H, 2.99; N, 14.87; S. 8.85.

Provenance & Evidence