Synthesis of 1,4‐bis(4‐pyridyl)butadiyne

Abstract

Abstract 2‐Methyl‐4‐(4‐pyridyl)‐3‐butyn‐2‐ol ( 2 ) was prepared in 70% yield by the reaction of 4‐bromopyridine with 2‐methyl‐3‐butyn‐2‐ol in diethylamine in the presence of bis(triphenylphosphine)palladium(II) chloride and copper(I) iodide. Removal of the protective group in 2 by refluxing with sodium hydroxide in toluene yields (90%) 4‐ethynylpyridine ( 3 ). Oxidative coupling of 3 in pyridine by dioxygen in the presence of copper(I) chloride produces a 92% yield of 1,4‐bis(4‐pyridyl)butadiyne.