Synthesis of 3,9,15,19,21,23‐Hexaazakekulene

Blue fluorescence is exhibited by the hexaazakekulene 1, the first fully aromatic heteroanalogue of kekulene. It was synthesized in four steps from formaldehyde and proflavine (3,6-diaminoacridine). Although 1 is insoluble in organic solvents, it is slightly soluble in strong acids such as methanesulfonic or trifluoroacetic acid—probably due to protonation.