Zeolite anchored Zr-ZSM-5 as an eco-friendly, green, and reusable catalyst in Hantzsch synthesis of dihydropyridine derivatives

In this study, the authors have developed a simple and eco-friendly metal switch over Zeo-catalyst Zr-ZSM-5. It is an efficient and novel reusable heterogeneous solid catalyst for one pot multi component synthesis of triphenyl pyridine- 3, 5-dicarboxamide, and 2,6-dimethyl-1,4- dihydropyridine-3, 5-dicarboxylate from Acetoacetanilide/ethyl acetoacetate, ACOONH(4)/NH4OH and various Aromatic Aldehydes. Reactions afforded very good product yields (87-95%) in a short reaction time (27-35 min) in ethanol at an appropriate temperature. Prepared catalyst was comfortably recycled for four to five times (4-5 runs) without significant loss of catalytic activity. Zr-ZSM-5 is also used as a green catalyst for the combinatorial syntheses of dihydropyridine. The solid catalyst was characterized by XRD, SEM/EDS and BET SA-PSD, and the resulting substituted dihydropyridine derivatives were characterized and confirmed by H-1 and C-13 NMR, IR, and elemental spectral data.