Réaction #80647

Équation de réaction

sodium acetate

hydroxylamine-O-sulfonic acid

2-methyl-3-[1-[4-[[2(trimethylsilyl)ethyl]sulfonyl]phenyl]-4-(trifluoromethyl) -1H-imidazol-2-yl]pyridine

2-methyl-3-[1-[4-[[2-(trimethylsilyl) ethyl]sulfonyl]phenyl]-4-(trifluoromethyl) -1H-imidazol-2-yl]pyridine

n-Bu4NF

→

4-[2-(2-methylpyridin-3-yl)-4-(trifluoromethyl)-1H-imidazol-1-yl]benzenesulfonamide

Rendement 84.0%

Solvants

water

Water

ethyl acetate

THF

Conditions de réaction

Traitement

1. 1
   TempératureThe mixture was heated
2. 2
   Températureto reflux for 1 hour
3. 3
   AutreThe organic phase was separated
4. 4
   Lavagewashed with sat. NaHCO3 solution, water, and brine
5. 5
   Séchagedried over MgSO4
6. 6
   Filtrationfiltered
7. 7
   ConcentrationThe filtrate was concentrated
8. 8
   Autrethe residue was purified by chromatography on silica gel (ethyl acetate/acetone, 95:5)

Mode opératoire

To a solution of 2-methyl-3-[1-[4-[[2(trimethylsilyl)ethyl]sulfonyl]phenyl]-4-(trifluoromethyl) -1H-imidazol-2-yl]pyridine from Step 1 (0.234 g, 0.0005 mol) in 1.5 mL of dry THF was added n-Bu4NF (1.5 mL of 1.0M THF solution, 1.5 mmol). The mixture was heated to reflux for 1 hour and cooled to room temperature. A solution of sodium acetate (0.19 g, 2.3 mmol) in 3 mL of water and hydroxylamine-O-sulfonic acid (0.28 g, 2.5 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 sat. NaHCO3 solution, water, and 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 0.16 g of 4-[2-(2-methylpyridin-3-yl)-4-(trifluoromethyl)-1H-imidazol-1-yl]benzenesulfonamide as a colorless solid (84%): mp 235°-237° C. Anal. Calc'd. for C16H13F3N4O2S: C, 50.26; H, 3.43; N, 14.65; S, 8.39. Found: C, 50.06; H, 3.29; N, 14.44; S, 8.52.

Source