Table 1.

Antiviral activity of the studied compounds against HIV-1

Compd	R1 = X	R2	R3	CC50 (μM)a	HIV-1 (IIIB) wild type		RT
					EC50 (μM)b	SIc	Ki (μM)d
4	H	H	H	193	9.5	20	68
5	2-Me	H	H	117	>117	—	>100
6	3-Me	H	H	207	31	6.7	>100
7	4-Me	H	H	187	11	17	52
8	4-t-Bu	H	H	63	>63	—	15
9	4-Ph	H	H	31	8.3	3.8	8.1
10	4-Cl	H	H	36	>36	—	22
11	4-F	H	H	187	27	6.9	71
12	4-CN	H	H	166	43	3.9	51
13	3,4-Me2	H	H	60	>60	—	>100
14	3,5-Me2	H	H	46	>46	—	>100
15	4-Me	2-Me	H	46	>46	—	>100
16	4-Me	3-Me	H	⩾38	3.4	⩾11	6.6
17	4-Me	4-Me	H	250	>250	—	47
18	4-Me	2,5-Me2	H	>343	5.2	>66	10
19	4-Me	3,5-Me2	H	>343	0.27	>1270	0.26
20	4-Me	2,4,6-Me3	H	133	>133	—	>100
21	—	—	Me	> 356	>356	—	1
22	—	—	H	129	>129	—	6.5
23	—	—	H	132	6.5	20	12
25	—	—	H	37	>37	—	1
27	—	—	—	25	>25	—	1
29	H	H	H	160	7.85	20	29
30	H	3,5-Me2	H	257	1.27	202	0.55
31	H	3,5-F2	H	31	8.4	4	12
32	H	3,5-Cl2	H	49	1.99	24	0.67
33	H	3,5-Br2	H	231	1.72	134	0.31
34	H	3-Br-5-Me	H	100	1.36	73	0.31
35	H	—	H	293	13	22	6.6
Nevirapine				>4	0.048	>400	7.2

^aCC₅₀, cytotoxic concentration; the concentration affording 50% death of noninfected MT-4 cells.

^bEC₅₀, effective concentration; the concentration affording 50% inhibition of virus replication in MT-4 cells.

^cSI, selectivity index, ratio CC₅₀/IC₅₀.

^dK_i, inhibition constant; the concentration of a non-competitive RT inhibitor ensuring 50% inhibition of the enzymatic activity.