Tandem Ring‐Opening/Double Ring‐Closing Synthesis of 1,2,4‐Triazolo[1,5‐a]pyridines from Chromone‐Containing Acrylonitriles

• DOI: 10.1002/adsc.202300934
• Publication Date: 2023-12-01T03:31:38Z
• Authors: Nikita M. Chernov; Roman P. Kustin; Yulia V. Pypa; Sergej O. Anisimov; Dar'ya V. Spirido...; Roman V. Shutov; Igor P. Yakovlev

AbstractWe studied a reaction of chromone‐containing acrylonitriles and cyanoacrylates with acid hydrazides. This reaction turned out to be a method for the synthesis of salicyloyl‐substituted 1,2,4‐triazolo[1,5‐a]pyridines. The synthesis developed is a tandem ring‐opening/double ring‐closing process. This synthetic approach is characterized by low toxic solvents (ethanol, butanol) and mediator (Et3N), 37–84% yields, non‐chromatographic isolation of products, and substrate tolerance (59 examples).