Synthesis of Functionalized Hemi‐1,2,4‐triazinyl‐[2,2′]‐bipyridines via Telescoped Condensation of [2,2′]‐bipyridinyl‐6‐carbonitrile

Abstract

Partitioning of neutron‐poisoning lanthanides from minor actinides in used nuclear fuel using liquid–liquid separation techniques with moderately soft Lewis basic heterocyclic scaffolds is an area of intense research focus. Nitrogen heterocycles have demonstrated potential for the selective separation of Am3+ from Eu3+ in separations processes. Improved synthetic strategies are required to access more diversified complexant scaffolds for further study. The present work describes an efficient synthetic strategy for the preparation of functionalized [2,2′]‐bipyridinyl scaffolds using Pd catalysis to prepare the requisite starting material and telescoped condensation to afford direct access to hemi‐1,2,4‐triazinyl‐[2,2′]‐bipyridines with aliphatic character and potentially greater solubility in less polar diluents. Synthetic method development, optimization, and substrate scope are reported herein.