反应详情

温度

97 °C

A mixture of methyl 2-bromo-4-methoxybenzoate (4) (5.9 g, 23.9 mmol), butyl vinyl ether (15.4 mL, 119.4 mmol), Ph3P (939.0 mg, 3.6 mmol), Et3N (4.3 mL, 31.0 mmol), and Pd(OAc)2 (343.0 mg, 1.8 mmol) in MeCN (45 mL) is stirred under argon at 97° C. for 18 h, cooled to room temperature, diluted with H2O (50 mL), and filtered through Celite® (H2O rinse). The filtrate is concentrated to dryness at reduced pressure. The residue plus tetrahydrofuran (140 mL) and 10% HCl (140 mL) were stirred for 2 h. After tetrahydrofuran removal at reduced pressure, the residue is extracted with dichloromethane (3×70 mL). The extract is washed (brine) and dried. After solvent removal at reduced pressure, the residue is purified on silica gel (16.7% to 33.3% ethyl acetate/hexane) to give 4.8 g (96%) of 5 as a yellow solid, mp 48-50° C. IR 2962, 1733, 1688, 1258 cm−1; 1H NMR (CDCl3) δ 2.50 (s, 3H, CH3CO), 3.86 (s, 6H, CH3O, CO2CH3), 6.76 (d, J=2.0 Hz, 1H, 3-PhH), 6.93 (dd, J=7.2, 2.0 Hz, 1H, 5-PhH), 7.90 ppm (d, J=7.2 Hz, 1H, 6-PhH).

1. temperaturecooled to room temperature
2. filtrationfiltered through Celite® (H2O rinse)
3. concentrationThe filtrate is concentrated to dryness at reduced pressure
4. stirringThe residue plus tetrahydrofuran (140 mL) and 10% HCl (140 mL) were stirred for 2 h
5. customAfter tetrahydrofuran removal at reduced pressure
6. extractionthe residue is extracted with dichloromethane (3×70 mL)
7. washThe extract is washed (brine)
8. customdried
9. customAfter solvent removal at reduced pressure
10. customthe residue is purified on silica gel (16.7% to 33.3% ethyl acetate/hexane)