Bernthsen Synthesis

A. Bernthsen, Ann. 192, 1 (1878); 224, 1 (1884).

Formation of 5-substituted acridines by heating diarylamines in organic acids or anhydrides, usually in the presence of zinc chloride:



A. Albert, The Acridines (London, 1951) p 67; A. Albert, Heterocyclic Compounds 4, 502 (1952); N. P. Buu-Hoi et al., J. Chem. Soc. 1955, 1082; R. M. Acheson in The Chemistry of Heterocyclic Compounds, A. Weissberger, Ed., Acridines (Interscience, New York, 1956) pp 19-25; F. D. Popp, J. Org. Chem. 27, 2658 (1962). Alkyl migration: L. H. Klemm et al., Heterocyclic Chem. 29, 571 (1992).