A new method for the oxidation of 1, 4-dihydropyridine derivatives by guanidinium nitrate in the presence of silica sulfuric acid under mild, heterogeneous and metal-free conditions

In this paper, a new and convenient method is introduced for the oxidation of a variety of Hantzsch 1, 4-dihydropyridine derivatives to their corresponding pyridine compounds using guanidinium nitrate and silica sulfuric acid. The reactions were carried out in dichloromethane at room temperature and the products were isolated at high to excellent yields.