反应详情

A 1-L single-neck round-bottomed flask equipped with a magnetic stirrer and reflux condenser was charged with 4-nitrophenylacetic acid (14.1 g, 77.5 mmol), anhydrous methanol (130 mL) and concentrated sulfuric acid (12.0 mL, 216 mmol), and the reaction mixture was heated at reflux for 16 h. After this time, the reaction was concentrated to dryness under reduced pressure. The resulting residue was partitioned between water (500 mL) and diethyl ether (200 mL) and the layers separated. The aqueous phase was extracted with diethyl ether (100 mL). The combined organic phases were washed with saturated aqueous sodium carbonate and dried over magnesium sulfate, and the drying agent was removed by filtration. The filtrate was concentrated under reduced pressure and dried to a constant weight under vacuum to afford a 96% yield of 1 (14.6 g) as a white solid: mp 45-46° C.; 1H NMR (500 MHz, CDCl3) δ 8.19 (d, 2H, J=8.5 Hz), 7.46 (d, 2H, J=8.5 Hz), 3.75 (s, 2H), 3.73 (s, 3H). Reference: Tetrahedron 2002, 58, 10113.

1. customA 1-L single-neck round-bottomed flask equipped with a magnetic stirrer
2. temperaturereflux condenser
3. temperaturethe reaction mixture was heated
4. temperatureat reflux for 16 h
5. concentrationAfter this time, the reaction was concentrated to dryness under reduced pressure
6. customThe resulting residue was partitioned between water (500 mL) and diethyl ether (200 mL)
7. customthe layers separated
8. extractionThe aqueous phase was extracted with diethyl ether (100 mL)
9. washThe combined organic phases were washed with saturated aqueous sodium carbonate
10. dry with materialdried over magnesium sulfate
11. customthe drying agent was removed by filtration
12. concentrationThe filtrate was concentrated under reduced pressure
13. customdried to a constant weight under vacuum