Acetic Anhydride → Butanoic acid, 2-(ethoxymethylene)-4,4-difluoro-3-oxo-, ethyl ester

Participants

Reaction Conditions

Reaction Steps

To the concentrated product of crude ethyl difluoroacetoacetate (˜0.93 mole) are added triethyl orthoformate (266.8 g, 1.8 moles) and acetic anhydride (367.6 g, 3.6 moles). The mixture is heated to 90-95° C., and kept gently refluxing for 6 hours. (GC shows ethyl difluoroacetoacetate content <0.1%). The reaction mixture is cooled to 60-70° C. and then concentrated under vacuum to remove excess acetic anhydride, triethyl orthoformate, and generated ethyl acetate. A pale brown liquid (178.6 g) is obtained. The yield of two steps is 80%.

Provenance & Evidence