An efficient method for the oxidation of 1,4-dihydropyridines under mild and heterogeneous conditions via in situ generation of NOCl

Abstract

A combination of inorganic chloride salts [e.g. AlCl3, ZrCl4, and ZnCl2] and sodium nitrite in the presence of wet SiO2 was used as an effective oxidising agent for the oxidation of dihydropyridines to their corresponding pyridine derivatives under mild and heterogeneous conditions in moderate to excellent yields.