Organic Chemistry Portal



Palladium-Catalyzed Chemoselective Monoarylation of Hydrazides for the Synthesis of [1,2,4]Triazolo[4,3-a]pyridines

Andreas Reichelt*, James R. Falsey, Robert M. Rzasa, Oliver R. Thiel, Michal M. Achmatowicz, Robert D. Larsen and Dawei Zhang

*Departments of Medicinal Chemistry and Chemical Process Research & Development, Amgen, Inc., One Amgen Center Drive, Thousand Oaks, California 91320-1799, Email:

A. Reichelt, J. R. Falsey, R. M. Rzasa, O. R. Thiel, M. M. Achmatowicz, R. D. Larsen, D. Zhang, Org. Lett., 2010, 12, 792-795.

DOI: 10.1021/ol902868q

see article for more reactions


An efficient and convenient synthesis of [1,2,4]triazolo[4,3-a]pyridines involves a palladium-catalyzed addition of hydrazides to 2-chloropyridine, which occurs chemoselectively at the terminal nitrogen atom of the hydrazide, followed by dehydration in acetic acid under microwave irradiation.

see article for more examples

Key Words

1,2,4-triazolo[4,3-a]pyridines, microwave synthesis

ID: J54-Y2010-0480