Room temperature fluorination of aromatic molecules with cesium fluoroxysulphate

Room -temperature fluorination of benzene with cesium fluoroxysulphate in the presence of boron trifluoride as catalyst resulted in the formation of fluorobenzene, while reaction with naphthalene gave 1-fluoro and 2-fluoronaphthalene in the ratio 5:1, the overall yield being between 38 and 42%. The fluorination of phenanthrene and pyrene should be carried out at higher dilution and needs no catalyst. Phenanthrene gave 9-fluorophenanthrene and 9, 9-difluoro-10-keto-9, 10-dihydrophenanthrene in the ratio 1:6 in a yield of about 70%, while pyrene gave 1-fluoro and 4-fluoropyrene in the ratio 7.5:1.