2,6-Disubstituted imidazo[2,1-b][1,3,4]thiadiazoles: search for anticancer agents.

In this study, some novel 2,6-disubstituted imidazo[2,1-b][1,3,4]thiadiazoles 4 (a-i), 7 (a-p) and 11 (a-i) were synthesized from 5-substituted-1,3,4-thiadiazol-2-amine. The newly synthesized compounds 4a, 4b, 4c, 4e, 4g, 7j, 7l, 11b and 11c were evaluated in the National Cancer Institute for single dose in vitro primary cytotoxicity assay. Among the tested nine compounds, compound 4b (107166/760239) and 4c (107168/760240) were passed the criteria for activity in this assay and scheduled automatically for evaluation against the full panel of 60 human tumor cell lines at a minimum of five concentrations at 10-fold dilutions. 3-(2-(4-methoxyphenyl)imidazo[2,1-b][1,3,4]thiadiazol-6-yl)aniline (4c) exhibited significant in vitro anticancer activity against Non Small Cell Lung Cancer HOP-92 cell line (GI(50): 0.114 μM) and Renal Cancer CAKI-1 cell line (GI(50): 0.743 μM).