– PF00835231(SARS-CoV-2 inhibitor 5h) is areversible-covalent inhibitor of SARS-CoV-2 main protease (Mpro) with EC50 of 4.2 ?M. Compound 5h blocks the infectivity and cytopathicity of the virus with high potency and without any detectable cytotoxicity even at 200??M.PF-00835231 is a potent inhibitor of CoV-2 3CLpro with IC50 of 4 nM and shows suitable pharmaceutical properties to warrant further development as an intravenous treatment for COVID-19.