Homolytic reactions of perfluoroaromatic compounds. Part IV. Formation of pentafluorophenyl radicals from pentafluoroaniline, and their reactions with aromatic compounds

Abstract

The pentafluorophenylation of benzene, hexafluorobenzene, chloro-, bromo- and nitro-benzene, and toluene, and the competitive pentafluorophenylation of an equimolar mixture of benzene and chlorobenzene with pentafluorophenyl radicals prepared by reaction of pentafluoroaniline with pentyl nitrite in the refluxing solvents are described. The reactions with the benzene derivatives gave mixtures of the products of pentafluorophenylation at the 2′-, 3′-, and 4′-positions, and the compositions of these mixtures were measured. The relative rate of pentafluorophenylation of chlorobenzene, and hence partial rate factors for this reaction were obtained. The results establish the electrophilic character of the pentafluorophenyl radical. Phenylation of hexafluorobenzene with radicals obtained analogously from aniline and pentyl nitrite gives 2,3,4,5,6-pentafluorobiphenyl.