oxidative cyclization of α-(o-iodophenyl)cinnamic acids as a new route to certain phenanthrene derivatives

Conclusions The cyclization of the-(o-iodophenyl)-m- and-(o-iodophenyl)-p-bromocinnamic acids using K₂S₂O₈ in conc. H₂SO₄ gave the 2-bromo- and 3-bromo-10-carboxydibenz[b,f]iodepinium betaines, whose thermolysis in conc. HI leads to the 2-bromo- and 3-bromo-9-phenanthrenecarboxylic acids. The analogous cyclization does not go in the case of the-(o-iodophenyl)-p- and-(o-iodophenyl)-o-nitrocinnamic acids.Deceased.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2530–2534, November, 1980.