Reaction of Perfluorobenzocyclobutene with Excess Pentafluorobenzene in SbF 5

The reaction of perfluorobenzocyclobutene with excess pentafluorobenzene in SbF5, followed by hydrolysis, gave a mixture of perfluoro-1,3,3-triphenyl-1,3-dihydro-2-benzofuran-1-ol, perfluoro-1,1,2-triphenylbenzocyclobuten- 5-one, and perfluoro-4-(2,2-diphenylbenzocyclobuten-1-ylidene)cyclohexa-2,5-dien-1- one. When the reaction mixture was treated for a long time with Olah’s reagent (HF–pyridine), isomeric perfluoro-9,10-diphenyl-1,4-, -1,10-, -2,9-, and -9,10-dihydroanthracenes were formed and were converted to perfluoro-9,10-diphenylanthracene by the action of SbF5.