Visible Light Promoted Catalyst Free, the Sustainable Synthesis of Dihydropyrano [2,3-C] Pyrazoles and Docking Studies with COVID-19 Mpro

Abstract

A highly efficient, simple, cost-effective, and environmentally benign method has been described for the synthesis of dihydropyrano[2,3-c]pyrazoles via one-pot, three-component condensation of 3-methyl-1- phenyl-2-pyrazoline-5-one, malononitrile, substituted aromatic aldehydes under visible light irradiation in catalyst-free condition at room temperature. This methodology's main advantage is good to excellent yield, simple work-up procedure, mild and clean reaction conditions, no chromatographic separation, and catalyst-free condition. All synthesized compounds are screened in silico with 6LU7, which is a COVID-19 Mpro. These computational studies were performed on AutoDock Vina, BIOVIA Discovery Studio 2017 R2, Auto Dock Tools-1.5.6 software. From screening results, we found that compound 4i and nitro group compounds 4d, 4e, 4f are showing a strong correlation at the active center of 6LU7. So, it is predicted that these compounds may be useful for COVID-19 patients.