Emerging SARS-CoV-2 variants of concern (VOCs) have demonstrated exceptional transmissibility and a strong dependence on the cellular receptor human angiotensin-converting enzyme 2 (hACE2). In this study, we present MB-32, a benzothiazole-based small molecule allosteric inhibitor of hACE2, which exhibits broad-spectrum antiviral activity against multiple SARS-CoV-2 VOCs, SARS-CoV-1, and bat/pangolin-derived sarbecoviruses. MB-32 effectively inhibits lung infections and prevents contact transmission of the SARS-CoV-2 Omicron in animal models. We subsequently studied the binding site of MB-32 on hACE2 using formaldehyde (FA) crosslinking coupled with mass spectrometry. To investigate FA crosslinking modifications, we utilized the mass of 558.22 Da, which is derived from the monoisotopic mass of MB-32 (534.22 Da) combined with a 2-carbon (24 Da) bridge, using PEAKS Studio 11. Focusing on four fixed amino acid type—saspartic acid, tyrosine, arginine, and lysine—we detected a 558.22 Da adduct in the combined mass of two peptides containing Y83 (EQSTLAQMY83PLQEIQNLTVK) and K94 (EQSTLAQMYPLQEIQNLTVK94), with high confidence scores of 1000.