INTRA-MOLECULAR NITRENE INSERTIONS INTO AROMATIC AND HETEROAROMATIC SYSTEMS .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 ORTHO-NITROPHENYLDI-(2-FURYL) OR ORTHO-NITROPHENYLBIS-(N-METHYLPYRROL-2-YL)-METHANES

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).