Strategies for the Synthesis of [1,2,4]Triazolo[1,5-a]pyridine-8-carbonitriles

: pp. 294 - 303
Department of Chemistry, Taras Shevchenko National University of Kyiv
Department of Chemistry, Taras Shevchenko National University of Kyiv
Department of Chemistry, Taras Shevchenko National University of Kyiv
Department of Chemistry, Taras Shevchenko National University of Kyiv
Department of Chemistry, Taras Shevchenko National University of Kyiv
Department of Chemistry, Taras Shevchenko National University of Kyiv

Conjugated heterocyclic compounds with a 1,2,4-triazole core are of scientific interest due to their wide application in both synthetic and medicinal chemistry. In this review, we comprehensively summarize the synthetic methods for [1,2,4]triazolo[1,5-a]pyridine-8-carbonitriles. The methods are classified as follows: convertion of 8-substituted [1,2,4]triazolo[1,5-a]pyridines; synthesis based on functionalized pyridines, containing a nitrile group; synthesis based on heterocyclization of 2-(1,2,4-triazol-5-yl)acetonitriles, including cyclocondensation of 2-(1,2,4-triazol-5-yl)acetonitriles with β-dicarbonyl compounds and heterocyclization of 2-(1,2,4-triazol-5-yl)acetonitriles with α,β-unsaturated nitriles and esters; cyclocondensation of acyclic reagents, namely hydrazine derivatives and substituted methylenemalononitriles or their precursors and recyclization of oxadiazolopyridi-nium salts upon the interaction with ammonia or amine.

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