Chemistry of Peri-condensed pyrroles. Synthesis of 4H-naphtho[1,4-def]carbazole. A new route to nitrotriphenylenes

Reaction of 1-nitrotriphenylene ( 7a ) with triethylphosphite (Cadogan reaction) produces 4H-naphtho[1,4-def]carbazole, a likely component of fossil fuels. Surprisingly 7a and its 2-isomer are obtained from treatment of triphenylene with sulfuric acid/trifluoroacetic anhydride in nitromethane. Correlation between ultraviolet spectra and substitution reactions in peri-condensed pyrroles and thiophenes is presented.