Application
Difluoroacetic anhydride is mainly used as an acylation reagent in organic synthesis to introduce difluoroacetyl groups. Difluoroacetate is mainly used as an intermediate in pesticides, pharmaceuticals, and fluorine-containing fine chemicals, and can also be used as a solvent in lithium battery electrolytes.
Synthesis
1. Difluoroacetic acid reacts with phosphorus pentoxide. Distillation yields difluoroacetic anhydride.
2. More difluoroacetic acid is added to the residue from step 1. Distillation gives a mixture containing the anhydride.
3. Difluoroacetic acid and methanol are added to the residue from step 2. Distillation yields methyl difluoroacetate.
4. The mixture from step 2 is reacted with phosphorus pentoxide. Distillation yields more difluoroacetic anhydride.