Microwave‐Assisted One‐Step Four‐Component Reaction for Synthesis of 1,4‐Dihydropyridines Catalyzed by Triethylamine

Abstract

Abstract A green approach is designed for the synthesis of 1,4‐dihydropyrine derivatives catalyzed by triethylamine with water as solvent and under microwave irradiation conditions. The title reaction involved the one‐pot condensation of four components, namely aryl aldehyde, benzyl acetoacetate, 5‐methyl‐1,3‐cyclohexanedione and ammonium acetate. Good to excellent yields (88‐98%), short reaction times (10 min), green solvent and simple workup are attractive features for the approach. The method requires no further chromatographic separation. The structures of all the ten new derivatives were fully characterized by spectroscopic analysis with 1 H NMR, 13 C NMR, 15 N NMR and HRMS.