Dibenzo[c,h]cinnoline oxides
Abstract
Dibenzo[c,h]cinnoline 5-oxide has been synthesised. The compound is not identical with the hydrogen peroxide oxidation product of dibenzo[c,h]cinnoline and the sodium sulphide reduction product of 1-nitro-2-o-nitrophenylnaphthalene, which must therefore be dibenzo[c,h]cinnoline 6-oxide, as previously supposed. Aside from steric interactions, electronic effects are made responsible for the exclusive formation of the 6-oxide in the latter two cases.