反应详情

温度

140 °C

p-Fluorobenzaldehyde (200 g, 1.61 mol), propionic anhydride (3.5 g, 2.42 mol) and sodium propionate (155 g, 1.61 mol) are mixed in a nitrogen-flushed 1 l three-necked flask. The flask is heated gradually in an oil-bath to 140° C. After 20 hours, the contents are cooled to 100° C., and are poured into 8 l of water. The precipitate is dissolved by adding potassium hydroxide (302 g) in water (2 l). The aqueous solution is washed with ether, and the ether layers are re-extracted with potassium hydroxide solution. The combined aqueous layers are filtered, are acidified with concentrated HCl, and are filtered. The collected solid, p-fluoro-α-methylcinnamic acid, is washed with water, and is dried and used as obtained.

1. customflushed 1 l three-necked flask
2. temperaturethe contents are cooled to 100° C.
3. additionare poured into 8 l of water
4. dissolutionThe precipitate is dissolved
5. additionby adding potassium hydroxide (302 g) in water (2 l)
6. washThe aqueous solution is washed with ether
7. extractionthe ether layers are re-extracted with potassium hydroxide solution
8. filtrationThe combined aqueous layers are filtered
9. filtrationare filtered
10. washThe collected solid, p-fluoro-α-methylcinnamic acid, is washed with water
11. customis dried
12. customas obtained