22841-90-3Relevant academic research and scientific papers
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
Ishimoto, Kazuhisa,Nagata, Toshiaki,Murabayashi, Mika,Ikemoto, Tomomi
, p. 407 - 418 (2015)
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.
