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

Org Lett. 2010 Feb 19;12(4):792-5. doi: 10.1021/ol902868q.

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.

MeSH terms

  • Acetic Acid / chemistry
  • Catalysis
  • Combinatorial Chemistry Techniques*
  • Cyclization
  • Hydrazines / chemistry*
  • Microwaves
  • Molecular Structure
  • Palladium / chemistry*
  • Pyridines / chemical synthesis*
  • Pyridines / chemistry*
  • Triazoles / chemical synthesis*
  • Triazoles / chemistry

Substances

  • Hydrazines
  • Pyridines
  • Triazoles
  • Palladium
  • 2-chloropyridine
  • Acetic Acid