Propionic anhydride → CID 367964

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

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.

Herkunft & Nachweise