Preparation of Fluoroarenes in One-Pot Diazotization and Fluoro-Dediazoniation of Aminoarenes Using HF or HF-Base. The Functions of Bases in the HF Solution

Abstract
In a one-pot diazotization of anilines followed by fluoro-dediazoniation in situ using HF or HF with bases (HF-Base) as a solvent, the diazotization stage has been found to play the most important part to yield fluoroarenes effectively. Diazotization of anilines was greatly influenced by the composition of the HF solution, and greatly enhanced by employing appropriate amounts of bases, such as pyridine. On the other hand, fluorodediazoniation of diazonium salts, once formed, took place very readily in HF or HF-Base to produce fluoroarenes in high yield, although such bases served to slow down the rate of decomposition of diazonium salts to some extent.