Table 1.

Inhibitory data of the target compound 18–33 against SARS-CoV-2 M^pro.

IDs
	R	R1	R2	R3	R4	IC50 (µM)
18.	H	H	Cl	H	H	12.77 ± 0.6
19.	H	H	Br	H	H	30.93 ± 1.6
20.	H	H	I	H	H	69.10 ± 3.50
21.	H	H	OCH3	H	H	24.55 ± 1.2
22.	H	H	OH	H	H	2.01 ± 2.15
23.	H	H	NO2	H	H	9.50 ± 0.51
24.	H	H	C6H5	H	H	39.84 ± 2.2
25.	F	H	F	H	H	191.7 ± 9.8
26.	Cl	Cl	H	H	H	41.76 ± 2.1
27.	Cl	H	Cl	H	H	1.83 ± 3.45
28.	Cl	H	H	Cl	H	16.4 ± 0.8
29.	Cl	H	H	H	Cl	44.64 ± 2.3
30.	H	Cl	Cl	H	H	100 ± 1.70
31.	H	H	OC2H5	H	H	4.60 ± 0.25
32.	H	OCH3	OH	H	H	14.59 ± 0.7
33.	H	OCH3	OCH3	OCH3	H	22.09 ± 1.10
Lopinavir	–	–	–	–	–	82.17 ± 6.77
GC-376	–	–	–	–	–	12.85 ± 0.74