Oxidative cyclization of 1-(pyridin-2-yl)guanidine derivatives using N-chlorosuccinimide and aqueous potassium carbonate has been investigated. Chlorination of 1-(5-nitropyridin-2-yl)guanidine by N-chlorosuccinimide in methanol followed by addition of aqueous potassium carbonate gave rise to cyclization and afforded 6-nitro-[1,2,4]triazolo[1,5-a]pyridin-2-amine in one-pot. In the course of studying the scope and limitation of the reaction, it was found that some of the examined 1-(pyridin-2-yl)guanidine derivatives gave not only the desired [1,2,4]triazolo[1,5-a]pyridin-2-amines but also unexpected [1,2,4]triazolo[4,3-a]pyridin-3-amine products. As plausible reaction mechanisms of this oxidative cyclization, diazirine formation and nitrene formation are presented.

已经研究了使用N-氯代琥珀酰亚胺和碳酸钾水溶液对1-（吡啶-2-基）胍衍生物的氧化环化作用。N-氯琥珀酰亚胺在甲醇中氯化1-（5-硝基吡啶-2-基）胍，然后加入碳酸钾水溶液进行环化，得到6-硝基-[1,2,4]三唑并[1,5-]一锅中有]吡啶-2-胺。在研究反应的范围和限制的过程中，发现某些检查过的1-（吡啶-2-基）胍衍生物不仅给出了所需的[1,2,4]三唑[1,5-]。a ]吡啶-2-胺，但也有意想不到的[1,2,4]三唑[4,3- a ]] pyridin-3-amine产品。作为这种氧化环化的合理反应机理，提出了重氮形成和氮形成。