A Synthesis of 1,2,4-Triazolo[1,5-f]phenanthridines by Rearrangements of 1,2,5-Oxadiazoles Involving an NCN Sequence with the Imine Nitrogen in an Aromatic Heterocyclic Ring

Abstract

A synthetic pathway to 1,2,4-triazolo[1,5-f]phenanthridine system by a base catalyzed rearrangement of 3-(6-phenanthridine)amino-1,2,5-oxadiazoles (5a,b) has been investigated. This ring transformation is the first example of the applicability of the mononuclear heterocyclic rearrangement involving an NCN sequence to the synthesis of bridged nitrogen systems