Large-scale solvent-free chlorination of hydroxy-pyrimidines,-pyridines,- pyrazines and-amides using equimolar POCl 3

Abstract

Chlorination with equimolar POCl 3 can be efficiently achieved not only for hydroxypyrimidines, but also for many other substrates such as 2-hydroxy-pyridines,-quinoxalines, or even-amides. The procedure is solvent-free and involves heating in a sealed reactor at high temperatures using one equivalent of pyridine as base. It is suitable for large scale (multigram) batch preparations. © 2012 by the authors.