Intramolecular nitrene insertions into aromatic and heteroaromatic systems. Part 5. Synthesis of diethyl 2-alkylfuro[3,2-c]carbazol-5-ylphosphonates and of 9-(N-methylpyrrol-2-yl)pyrrolo[3,2-b]quinoline by deoxygenation of o-nitrophenyldi-(2-furyl)- or o-nitrophenylbis-(N-methylpyrrol-2-yl)-methanes

Abstract

Deoxygenation of o-nitrophenylbis-(2-alkyl-5-furyl)methanes (2)–(4), using triethyl phosphite, gives diethyl 2-alkylfuro[3,2-c]carbazol-5-ylphosphonates (6)–(8). The mechanism of the reaction is discussed. Similar deoxygenation of o-nitrophenylbis-(N-methylpyrrol-2-yl) methane (12) gives 1-methyl-9-(N-methylpyrrol-2-yl)pyrrolo[3,2-b]quinoline (13).