Synthesis and oxidative behaviour of reduced indeno[1,2-b]quinoxalines and benzo[b]phenazines

Abstract

New routes to tetracyclic quinoxalines have been explored and their oxidative behaviour has been examined. Only if such compounds are devoid of benzylic hydrogen atoms are the corresponding cation radicals stable. Attempts to prepare certain polymethylated quinoxalines failed because of steric problems, and evidence is presented to show that in the case of some monohydrochloride salts proton migration between two nitrogen atoms is discernable through ¹H NMR spectroscopy.