Palladium-catalyzed chemoselective monoarylation of hydrazides for the synthesis of [1, 2, 4] triazolo [4, 3-a] pyridines

…, OR Thiel, MM Achmatowicz, RD Larsen, D Zhang

Index: Reichelt, Andreas; Falsey, James R.; Rzasa, Robert M.; Thiel, Oliver R.; Achmatowicz, Michal M.; Larsen, Robert D.; Zhang, Dawei Organic Letters, 2010 , vol. 12, # 4 p. 792 - 795

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Citation Number: 48

Abstract

An efficient and convenient method for the synthesis of [1, 2, 4] triazolo [4, 3-a] pyridines was exemplified by the synthesis of 20 analogues bearing a variety of substituents at the 3- position. The methodology 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.