反应详情

温度

0 °C

To a solution of (S)-2-(2-Bromo-6-methyl-4-nitrophenyl)-2-hydroxyethyl pivalate (13 g, 0.036 mol) in t-BuOAc (300 mL) at 0° C. was added HClO4 (20.7 g, 0.144 mol) slowly. The solution was stirred at 0° C. for 5 min, then warmed to room temperature and stirred at this temperature for 1.5 h. The solution was alkalized by saturated aqueous NaHCO3 until the pH of solution >8. The mixture was extracted with EtOAc (3×1 L). The combined organic layers were dried over anhydrous Na2SO4, filtered, concentrated in vacuo, and purified by silica gel column (Petroleum Ether:EtOAc (50:1)) to afford (S)-2-(2-Bromo-6-methyl-4-nitrophenyl)-2-tert-butoxyethyl pivalate (9.3 g, 62%) as yellow solid. 1H-NMR: 400 MHz, (CDCl3) δ: 8.26 (s, 1H), 7.98 (s, 1H), 5.60-5.57 (m, 1H), 4.32-4.27 (m, 1H), 4.18-4.14 (m, 1H), 2.73 (s, 3H), 1.17 (s, 9H), 1.14 (s, 9H).

1. temperaturewarmed to room temperature
2. stirringstirred at this temperature for 1.5 h
3. extractionThe mixture was extracted with EtOAc (3×1 L)
4. dry with materialThe combined organic layers were dried over anhydrous Na2SO4
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. custompurified by silica gel column (Petroleum Ether:EtOAc (50:1))