ZEOLITE A/Zn[Cl.sub.2] NANOPARTICLES AS A CATALYST FOR ECO-FRIENDLY SYNTHESIS OF PYRAZOLE-1-CARBOTHIOAMIDES WITH DOCKING VALIDATION AS COVID-19 MAIN PROTEASE INHIBITOR

The synthesized Zeolite A/Zn[Cl.sub.2] nanoparticles via the hydrothermal route were characterized using FTIR, XRD, and SEM/EDAX techniques. The characterized catalyst was used for the eco-friendly synthesis of 4,5-dihydro-pyrazole-1-carbothioamide derivatives. Under solvent-free conditions, a multi-component reaction between hydrazine, isothiocyanate, and chalcone was done with a prepared nano-catalyst as an inexpensive, recyclable, easy-to-get, and nontoxic catalyst. The molecular docking study explained that dihydro-1-carbothioamide pyrazoles can be considered COVID-19 main protease ([M.sup.pro]) inhibitors. In order to investigate the 3D conformation of the compounds that were synthesized, the density functional theory (DFT) was applied with a B3LYP hybrid functional and a 6-311++ G(d,p) basis set. This allowed us to investigate the compounds' electronic and charge transfer properties. In this series of compounds, the derivative 30d showed the lowest HOMO--LUMO energy gap. KEY WORDS: Zeolite A/Zn[Cl.sub.2] nanoparticles, Pyrazole-1-carbothioamides, Docking, XRD, SEM/EDX, HRTEM