Table 2. Cross-Reactivity Profile of Oxadiazole Series.

compd	R1	R2	Y	ITPa IC50 (μM)	G2/M blockb EC50 (μM)	VEFGR-2 enzyme IC50 (μM)	VEGFR-2 cell IC50 (μM)
6	benzo[1,3]dioxol-5-yl	pyridin-4-yl	N	1.0 ± 0.15	0.020 ± 0.003	1.89 ± 0.13	>10
7	benzo[1,3]dioxol-5-yl	pyridin-4-yl	CH	0.69 ± 0.01	0.62 ± 0.03	0.83 ± 0.07	>10
8	2,2-difluoro-benzo[1,3]dioxol-5-yl	pyridin-4-yl	N	3.9 ± 0.28	>10	3.16 ± 0.22	>10
9	benzo[1,3]dioxol-5-yl	pyridin-3-yl	N	8.8 ± 0.7	0.031 ± 0.001	>10	>10
10	benzo[1,3]dioxol-5-yl	pyridin-2-yl	N	1.7 ± 0.20	0.049 ± 0.01	>10	>10
11	benzo[1,3]dioxol-5-yl	benzo[1,3]dioxol-5-yl	N	2.5 ± 0.4	0.52 ± 0.09	>10	>10
12	benzo[1,3]dioxol-5-yl	2-(pyridin-3-yl) ethyl	N	1.7 ± 0.02	>10	3.41 ± 0.09	>10
13	benzo[1,3]dioxol-5-yl	2-(pyridin-4-yl) ethyl	N	>10	>10	>10	>10
14	2,3-dihydro-benzo[1,4]dioxin-6-yl	pyridin-4-yl	N	0.5 ± 0.01	0.018 ± 0.0024	0.17 ± 0.03	1.0 ± 0.05
15	2,3-dihydro-benzo[1,4]dioxin-6-yl	pyridin-3-yl	N	0.70 ± 0.03	0.013 ± 0.002	>10	>10
16	2,3-dihydro-benzo[1,4]dioxin-6-yl	pyridin-2-yl	N	1.9 ± 0.11	0.016 ± 0.001	>10	>10
17	2,3-dihydro-benzo[1,4]dioxin-6-yl	pyridin-4-yl	CH	1.09 ± 0.13	0.009 ± 0.002	0.21 ± 0.001	0.11 ± 0.02
18	2,3-dihydro-benzo[1,4]dioxin-6-yl	benzo[1,3]dioxol-5-yl	N	0.71 ± 0.11	0.018 ± 0.002	2.6 ± 0.1	>10
19	2,3-dihydro-benzo[1,4]dioxin-6-yl	2-(pyridin-3-yl) ethyl	N	>10	>10	>10	>10
20	2,3-dihydro-benzo[1,4]dioxin-6-yl	2-(pyridin-4-yl) ethyl	N	>10	>10	>10	>10
21	2,3-dihydro-benzo[1,4]dioxin-6-yl	imidazol-5-yl	N	1.5 ± 0.15	0.01 ± 0.017	0.16 ± 0.02	0.83 ± 0.04
22	2,3-dihydro-benzo[1,4]dioxin-6-yl	indazol-5-yl	N	1.25 ± 0.07	0.034 ± 0.001	1.4 ± 0.3	>10
23	2,3-dihydro-benzo[1,4]dioxin-6-yl	quinoline-6-yl	N	1.45 ± 0.11	0.018 ± 0.002	0.30 ± 0.02	0.22 ± 0.04

^aCompound concentration required for 50% inhibition of maximum tubulin assembly.

^bCompound concentration required for 50% of A431 cells to accumulate at the G₂M phase of the cell cycle.