Cationic triazinium heterocycles by intramolecular NN bond formation

Tricyclic heterocycles with a cationic triazinium core were prepared by an intramolecular NN bond forming reaction of an azine oxime precursor. The azine oxime substrates were prepared by SNAr N-arylation of 2-formylpyrroles followed by oxime formation of the formyl moiety. The synthesis was demonstrated with five different azines and several functional groups.