Synthesis of 1,2,4-Triazolo4,3-apyridines and Related Heterocycles by Sequential Condensation and Iodine-Mediated Oxidative Cyclization

摘要

A facile and efficient approach to access 1,2,4-triazolo4,3-apyridines and related heterocycles has been accomplished through condensation of readily available aryl hydrazines with corresponding aldehydes followed by iodine-mediated oxidative cyclization. This transition-metal-free synthetic process is broadly applicable to a variety of aromatic, aliphatic, and alpha,beta-unsaturated aldehydes, and can be conveniently conducted on the gram scale.