Siver salts/ iodine monochloride as a new oxidation system for the oxidative aromatization of 1, 4-dihydropyridines

Abstract

Silver salts such as silver nitrate and silver oxide have been found to promote oxidative aromatization of various 1, 4-dihydropyridines to their corresponding pyridine derivatives by iodine monochloride under heterogeneous conditions in dichloromethane at room temperature. Silver oxide in comparison to silver nitrate promoted the oxidation to completion without any by-products in shorter reaction times and cleaner conditions. The products were separated by simple filtration of reaction mixture and evaporating of solvent and identified by physical and spectral data.