Zur Frage der Lactam‐Lactim‐Tautomerie. II. Mitteilung: Oxydation von Imidazol und seinen Derivaten durch Perbenzoesäure

Oxidative Degradation of Imidazoles by Bromine or N-Bromosuccinimide*

“…In recent discussions on the chemistry of imidazoles, an emphasis on their lack of reactivity toward oxidants such as chromic acid (Acheson, 1960;Albert, 1959;Katritzky and Lagowski, 1960;Wiley, 1953;Loudon, 1957) has somewhat overshadowed the fact that imidazole rings are easily oxidized4 and ruptured by permanganate (Wyss, 1877;Pinner and Schwarz, 1902;Jowett and Potter, 1903), periodate,5 peracids (Botwinnik and Prokofjev, 1937), hydrogen peroxide (Radziszewski, 1884;Von Euler and Hasselquist, 1958;Pinner and Schwarz, 1902;Nofre et al, 1961;Inoue, 1953), ozone (Langenbeck, 1924), and ultraviolet light (Weil et al, 1951;Sluyterman, 1961; Schreiber and Pfenningsdorf, 1961). However, the only previous indication that halogen is capable of degrading the imidazole ring follows from the isolation of ammonium bromide upon bromination of the heterocyclic base (Balaban and Pyman, 1922).…”