Oxidative cyclization of 1-(pyridin-2-yl)guanidine derivatives: a synthesis of [1,2,4]triazolo[1,5-a]pyridin-2-amines and an unexpected synthesis of [1,2,4]triazolo[4,3-a]pyridin-3-amines
作者:Kazuhisa Ishimoto、Toshiaki Nagata、Mika Murabayashi、Tomomi Ikemoto
DOI:10.1016/j.tet.2014.12.015
日期:2015.1
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
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。