Synthesis and Trapping of 3,4,3',4'-Tetradehydrobiphenyl (Bisbenzyne)

3,3'-Dicarboxy-4,4'-diaminobiphenyl was synthesized from Onitrobenzoic acid following standard procedures. Diazotization of this compound with isoamylnitrite, under approtic condition gave diphenyl-4,4'-bis-diazonium-3,3'-dicarboxylate and subsequent thermal decomposition of this diazonium compound produced 3,4,3',4'-tetradehydrobiphenyl (bisbenzyne) as a reactive intermediate. Bisbenzyne was trapped with the diene 2,3,4,5-tetraphenylcyclopentadienone via a [4+2]diels-Alder cycloaddition reaction yielding the previously unreported 5,6,7,8,5',6',7',8'-octaphenyl-2,2'-binaphthyl. This novel compound was fully characterized by elemental analysis IR and 1HNMR spectroscopy.