Table 3.

SAR data for CK1δ/ε inhibitors with a substituted benzimidazole unit (R₅)

№	R5	R6	CK1δ IC50 (nM)[a]	CK1ε IC50 (nM)[a]	MDA-MB-231EC50 (nM)[b]
36		N-Me	1565	2955	- [c]
37		O	1155	2095	- [c]
38		NH	825	1840	- [c]
39		N-Me	335	630	- [c]
40		O	520	715	- [c]
41		NH	430	915	- [c]
42		N-Me	100	320	< 1
43		O	50	105	4
44		NH	80	255	6
45		N-Me	610	335	- [c]
46		O	520	975	- [c]
47		NH	625	1765	- [c]
48		N-Me	200	660	1040
49		O	175	340	60

^[a]Biochemical assay.

^[b]Cellular proliferation assay.

^[c]Not determined.