Zinc Acetate-Catalyzed Efficient Synthesis of Hantzsch 1,4-Dihydropyridines

Abstract

The Hantzsch multicomponent reaction is the classical synthetic approach toward 1,4-dihydropyridines (1,4-DHPs), compounds of great interest in medicinal chemistry and material science. We herein report a green and extremely efficient synthesis of Hantzsch ester derivatives catalyzed by inexpensive and easily available zinc acetate (10 mol%). The reaction was carried out in a sealed tube at 80 °C for 1-6 min under expedited and solvent-free conditions, yielding the required eleven dihydropyridine derivatives in good to excellent yields (67-96 %) and greatly decreased reaction time. The simple work-up and no solvent waste and recyclability of the catalyst (up to four cycles) make this technique as a better and environmentally sustainable alternative.