Cation radicals: oxidative coupling of carbazoles, 10,11-dihydro-5H-dibenz[b,f]azepines and related derivatives by 2,3-dichloro-5,6-dicyano-p-benzoquinone and tris-(p-bromophenyl)ammoniumyl salts
Reactions of carbazoles and 10,11-dihydro-5H-dibenz[b,f]azepines with 2,3-dichloro-5,6-dicyano-p-benzoquinone in the presence of acids, and with tris-(p-bromophenyl)ammoniumyl salts gave good yields of cation radical salts from ring coupled dimers. Corresponding reactions with iminostilbenes gave mixtures of dimers which could not be separated.