反应详情

Into a 500-ml, round-bottom flask equipped with a magnetic stirrer, heating mantle and condenser were placed 5.7 g (33.5 mmol) methyl 3-fluoro-4-hydroxybenzoate, 8.5 g (43.2 mmol) 1-bromo-2-(2-ethoxyethoxy)-ethane, 23.2 g of powdered anhydrous potassium carbonate and 350 ml acetonitrile. After stirring the reaction mixture under reflux for four hours, TLC analysis showed that none of the phenolic starting material remained. Three hundred ml of the acetonitrile was then distilled off and 300 ml dichloromethane was added. The reaction mixture was filtered through Celite and the solids were washed thoroughly with dichloromethane. Evaporation of the filtrate yielded product in the form of a yellow oil. Purification by flash chromatography on silica gel with 4% ethyl ether in dichloromethane, followed by low temperature recrystallization from pentane, yielded 8.55 g of white crystals, 89%, m.p. 33°-36.5° C. The structure was confirmed by infrared, nuclear magnetic resonance and mass spectral analyses. ##STR32##

1. customInto a 500-ml, round-bottom flask equipped with a magnetic stirrer
2. temperatureheating mantle and condenser
3. temperatureunder reflux for four hours
4. distillationThree hundred ml of the acetonitrile was then distilled off
5. addition300 ml dichloromethane was added
6. filtrationThe reaction mixture was filtered through Celite
7. washthe solids were washed thoroughly with dichloromethane
8. customEvaporation of the filtrate
9. customyielded product in the form of a yellow oil
10. customPurification by flash chromatography on silica gel with 4% ethyl ether in dichloromethane
11. customfollowed by low temperature recrystallization from pentane