A new method for making acyl fluorides using BrF3

While many carboxylic acids could be converted directly to acyl fluorides by using BrF3, the reaction with acyl chlorides was found to be of a more general nature and yields better results. Surprisingly, reacting t-butyl esters with bromine trifluoride also resulted in acyl fluorides in reasonable yields. The reactions were completed in a few seconds at 0 °C.

Carboxylic acids, acyl chlorides and t-butyl esters can be readily converted to the corresponding acyl fluorides by a fast reaction with BrF3. Figure optionsDownload as PowerPoint slide