Regioselective Nitration of Halogenated Benzo[c]cinnolines and Benzenoids.

Electrophilic nitration of halo-substituted benzo[c]cinnolines and benzenoids has been achieved regioselectively. The nitro group entry was always ortho to the halo group or/and the aromatic ring. This regioselective electrophilic ortho-nitration was accomplished in mixed acid/mild temperature conditions. Regioselectivity ortho to the halo/ring group(s) was observed with or without proximal steric hindrance. Chlorides and bromides worked equally well in directing these high-yielding ortho-selective reactions.