With a slight structural modification from benzotriazole ester, Zhang et al. reported a series of active halopyridyl esters containing thiophene, furan, and indole moieties (92–95; Figure 26). Among them, 93 displayed the highest enzymatic inhibitory activity at SARS‐CoV‐1 Mpro. 169  However, no antiviral activity for this compound was communicated. The irreversible binding mode of 93 was confirmed by ESI‐MS analysis. 170 ,  171