Table 1.

Top1 inhibitory activities of synthesized compounds.

Comp.	X	R	Overall Yield (%)	Relaxation Assay a	Comp.	X	R	Overall Yield (%)	Relaxation Assay a
6	F	H	20.3	++	22	Cl	3-Me	28.1	++
7	F	2-Me	24.8	++	23	Cl	4-tert-Bu	25.9	+
8	F	3-Me	25.0	++++	24	Cl	2-OMe	33.9	++
9	F	4-Me	24.7	+	25	Cl	2-Cl	31.9	+
10	F	4-CF3	26.4	+++	26	Br	3-Me	29.1	++
11	F	4-tert-Bu	24.5	+++	27	Br	4-CF3	25.2	++
12	F	2-OMe	22.2	++	28	Br	4-tert-Bu	27.2	+
13	F	3-OMe	22.9	+++	29	Br	4-F	20.8	++
14	F	4-OMe	25.8	+	30	Br	2-OMe	24.9	+
15	F	4-F	21.4	+++	31	Br	3-OMe	26.5	+
16	F	2-Cl	25.2	++	32	Br	4-OMe	29.0	+
17	F	4-Cl	21.2	+	33	Br	2-OH	15.8	+
18	F	2-Br	19.8	++	34	Br	3-OH	17.3	+
19	F	3-Br	21.2	+++	35	Br	4-OH	21.7	+
20	F	2,4-di-Cl	19.6	+	36	Br	3-O-prenyl	10.8	++
21	Cl	2-Me	30.2	+	37	Br	4-O-prenyl	12.6	+

^a Top1 inhibitory activity was semi-quantitatively expressed relative to CPT at 50 μM as follows: ++++, more than 80% activity; +++, between 40% and 79% activity; ++, between 10% and 39% activity; +, less than 10% activity. Every experiment was repeated at least twice, independently.