1,2,4‐Oxadiazole[4,5‐a]piridinium chloride adds nucleophiles to undergo electrocyclic ring opening affording 1,2,4‐oxadiazole dienamino derivatives. These pyridinium salts represent a special class of Zincke salts that are prone to rearrange when treated with primary amines or in the presence of bicarbonate to give the pyridones. The pivotal tuning of the experimental conditions leads to a straightforward synthesis of valuable 1,2,4‐oxadiazole dienamine derivatives. The mechanism is also discussed in the light of NMR experiments and theoretical calculations.

中文翻译：

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1,2,4-Oxadiazole [4,5-a]氯化吡啶鎓的电环开环：1,2,4-Oxadiazole二烯氨基化合物的新途径。

1,2,4-氧杂二唑[4,5- a ]氯化吡啶鎓使亲核试剂发生电环开环，从而得到1,2,4-恶二唑二烯氨基衍生物。这些吡啶鎓盐代表一类特殊的Zincke盐，当用伯胺处理或在碳酸氢盐存在下容易产生吡啶酮时，它们倾向于重排。实验条件的关键调整可直接合成有价值的1,2,4-恶二唑二烯胺衍生物。还根据NMR实验和理论计算对机理进行了讨论。