当2-(苯基乙炔基)吡啶被氧化时,形成的N-氧化物立即在乙炔基上环化,形成异恶唑并[2,3- a ]吡啶鎓盐。该盐在碱的存在下与酒精进行Reissert-Henze型反应,得到6-取代的2-苯并吡啶,很难通过替代方法合成。当使用乙腈作为溶剂时,将酰胺官能团引入到苯并吡啶骨架中。此外,在将反应混合物简单暴露于空气后,在6-位的杂原子促进了苯甲酰基的氧化以提供α-二酮。
Oxidation of 2-(phenylethynyl)pyridine with H2O2-AcOH gave isoxazolo[2,3-a]pyridinium acetate, which was successively attacked by alcohols in the presence of Na2CO3 to afford 6-alkoxy-substituted 2-phenacylpyridines in moderate yields. It was also possible to introduce amino or alkylthio functionality onto the pyridine ring by similar process. The present reaction is a new example of intramolecular Reissert-Henze-type reaction.