反应详情

Bromine (0.072 ml, 1.4 mmol) was added to a suspension of zinc dust (1.41 g, 21.57 mmol) in diethyl ether (25 ml) at RT. After 5 minutes, ethyl 2-bromoacetate (1.202 ml, 10.8 mmol) was added drop wise over a time period of 10 minutes and the reaction mixture was heated to reflux for 2 hours. 7-Bromo-3-chloro-5H-chromeno[2,3-c]pyridin-5-one (2 g, 6.44 mmol) was added in one portion, followed by THF (25.00 ml) and the reaction mixture was heated to reflux for 30 minutes. The reaction mixture was quenched with aqueous saturated NH4Cl solution (20 mL) and water (20 mL) and stirred 30 min at RT. The solution was filtered and the organic phase was separated. The solvent was removed under educed pressure to afford ethyl 2-(7-bromo-3-chloro-5-hydroxy-5H-chromeno[2,3-c]pyridin-5-yl)acetate (2.5 g, 6.27 mmol, 97% yield).

1. temperaturethe reaction mixture was heated
2. temperatureto reflux for 2 hours
3. temperaturethe reaction mixture was heated
4. temperatureto reflux for 30 minutes
5. customThe reaction mixture was quenched with aqueous saturated NH4Cl solution (20 mL) and water (20 mL)
6. filtrationThe solution was filtered
7. customthe organic phase was separated
8. customThe solvent was removed