Green Catalytic Pathway for the Synthesis of 1,4-Dihydropyridine Derivatives

Background: The rising number of health problems and diseases leads to demands and medical advancement. These increasing demands have led us to work on catalysis which ultimately increases the yield of pharmaceutically important drugs. Methods: Synthesis of 9, 10-diarylacridine-1, 8-dione has been carried out by single-pot, efficient and environmentally benign Hantzsch condensation reaction, which includes three component reactants i. e. aldehyde, amine and 5, 5-Dimethyl-1, 3-cyclohexanedione (dimedone). Zeolite LTL has been synthesized and modified by using three different metal oxides i. e. SrO, CuO and Cr2O3. Comparative studies based on % yield at varying parameters have been performed with different metal oxide modified zeolite-LTL which signifies the catalytic efficiency of various metal oxides and H-form zeolite. The competency of nanoporous modified zeolite-LTL has also been observed under various parameters (i. e. different solvent, temperature, catalyst concentration, time interval and catalytic recycling) with respect to the percentage yield of various compounds. Results: The synthesized nanoporous zeolites have been characterized by the help of Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), BET Surface Area and Porosity Analysis and Scanning Electron Microscopy-Energy dispersive X-ray spectroscopy (SEM-EDX) while the structures of the drug derivatives have been confirmed by Fourier Transform Infrared Spectroscopy (FTIR), 1H-Nuclear Magnetic Resonance Spectroscopy (1H-NMR) and Liquid Chromatography-Mass spectrometer (LC-MS). XRD, FT-IR and BET studies confirmed that the structure of zeolite hadn't deformed/altered by incorporation of metal oxide nanoparticles. Also, BET and XRD results confirmed the mesoporous structure of zeolite LTL. The reactivity was found highest in ethanol with HLTL at 90 degrees C for 60 min. i. e. 89.88%. Conclusion: The main advantages were short reaction time, excellent yield, low catalyst loading, high purity of the products due to the heterogeneous and harmless properties of zeolite. The protonated form of zeolite was found to be highly reactive due to presence of high surface area and greater number of active acid sites (Bronsted Active sites). The expeditious yield has been achieved by using catalysts which can be helpful to fulfill the demands of increasing health problems. The recyclability, heterogeneous nature and thermal stability of zeolites also increase the merit of this protocol.