反应详情

温度

0 °C

To a suspension of (S)-1-(2-Bromo-6-methyl-4-nitrophenyl)ethane-1,2-diol (17.0 g, 61.6 mmol) in DCM (435 mL) at 0° C. was added pyridine (18.6 g, 235.4 mmol) and PivCl (13.4 g, 110.8 mmol) slowly. After stirring at 0° C. for 5 min, the system was raised to room temperature and stirred at this temperature for 5 h. TLC showed the reaction was complete. The reaction mixture was treated with saturated aqueous NaHCO3 (500 mL), and the resulting system was extracted with DCM (2×200 mL). The combined organic layer was dried over anhydrous Na2SO4, filtered, concentrated in vacuum, and purified by silica gel column (Petroleum Ether:EtOAc (30:1)) to afford (S)-2-(2-Bromo-6-methyl-4-nitrophenyl)-2-hydroxyethyl pivalate (17 g, 77%) as yellow solid. 1H-NMR: 400 MHz, (CDCl3) δ: 8.28 (s, 1H), 8.00 (d, J=2.0 Hz, 1H), 5.70-5.66 (m, 1H), 4.58-4.53 (m, 1H), 4.31-4.26 (m, 1H), 2.84 (d, J=5.6 Hz), 2.68 (s, 3H), 1.22 (s, 9H).

1. temperaturethe system was raised to room temperature
2. stirringstirred at this temperature for 5 h
3. extractionthe resulting system was extracted with DCM (2×200 mL)
4. dry with materialThe combined organic layer was dried over anhydrous Na2SO4
5. filtrationfiltered
6. concentrationconcentrated in vacuum
7. custompurified by silica gel column (Petroleum Ether:EtOAc (30:1))