The catalytic influence of phosphotungstic acid-functionalized Fe(3)O(4) MNPs blended with TiO(2) on the synthesis of novel spiro-acridines and the evaluation of their medicinal potential through molecular docking studies.

This manuscript describes an effective and rapid three-component synthesis of a novel series of spiro-acridine derivatives by integrating the pharmacologically dynamic hydantoin-phenytoin as the prime synthetic equivalent. The process was accelerated by Fe(3)O(4)@TiO(2)-PTA magnetic nanoparticles (MNPs), which acted as the heterogeneous catalytic system, under ultrasonic conditions. The reaction was performed in the green PEG-200 solvent under aerophilic conditions to obtain products with excellent yields. The characteristics of the synthesized magnetic nano-catalysts were corroborated through powder X-ray diffraction (PXRD), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDAX), FT-IR, and VSM techniques. In addition, the structures of the synthesized compounds were ascertained on the basis of elemental analyses and spectro-analytical data ((1)H NMR, (13)C NMR, and mass spectrometry). High yields, smaller E-factor, considerable atom economy, easy recovery, and recyclability of the catalyst and solvent are the captivating features of the developed protocol. Moreover, in view of the ongoing global research on COVID-19, herein, we tried to identify the potential sites of the synthesized moiety that can suitably fit the receptor sites of the main protease of SARS-CoV-2 (SARS-CoV-2 M(pro)).