4-Phenyl-1,2,4-triazole-3,5-dione as a novel and reusable reagent for the aromatization of 1,4-dihydropyridines under mild conditions

4-Substituted 1,3,4-triazole-3,5-diones were used as effective and recyclable oxidizing agents for the oxidation of 1,4-dihydropyridines to the corresponding pyridine derivatives under mild conditions with good to excellent yields.