Tetrahedron letters

Convenient two-step preparation of [1, 2, 4] triazolo [4, 3-a] pyridines from 2-hydrazinopyridine and carboxylic acids

A Moulin, J Martinez, JA Fehrentz

Index: Moulin, Aline; Martinez, Jean; Fehrentz, Jean-Alain Tetrahedron Letters, 2006 , vol. 47, # 43 p. 7591 - 7594

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Citation Number: 17

Abstract

Triazolopyridines are an important class of biologically active heterocyclic compounds. In this letter, we describe a new method for the synthesis of [1, 2, 4] triazolo [4, 3-a] pyridines starting from 2-hydrazinopyridine and carboxylic acids. The resulting acetohydrazides are cyclized in a key step using the Lawesson's reagent. The reaction conditions were explored, as well as the scope of this reaction concerning the substituent in position 3 of the ...