Efficient one-pot four-component synthesis of 1,4-dihydropyridines promoted by magnetite/chitosan as a magnetically recyclable heterogeneous nanocatalyst

摘要

1,4-Dihydropyridines are synthesized from various aromatic aldehyde, dimedone or 1,3-cyclohexandione, ethyl acetoacetate or methyl acetoacetate and ammonium acetate catalyzed by magnetite/chitosan at room temperature under mild reaction conditions. This process offers an easy and efficient synthesis of 1,4-dihydropyridine derivatives in high yields. The benefits of this protocol are simplicity, nontoxicity, low cost, simple work-up, and an environmentally benign nature. The catalyst is recovered by filtration and reused at least five times without significant loss in catalytic activity.