Synthesis and biological evaluation of 5-formyl-6-arylimidazo(2,1-b)-1,3,4-thiadiazole-2-N-(dimethylaminomethi no) sulfonamides as antitumor agents.

In search for potential anti cancer drug candidates in imidazo (2,1-b)-1,3,4-thiadiazole series, two series of 5-formyl-6-arylimidazo(2,1-b)-1,3,4-thiadiazole-2-N- (dimethylaminomethino) sulfonamides and 5-bromo-6-aryl/ethylacetateimidazo(2,1-b)-1,3,4- thiadiazole-2-sulfonamides were synthesised. All compounds showed significant cytotoxic effects (log10 GI50 < -4.0, log molar drug concentration required to cause 50% growth inhibition) against a variety of human tumor cell lines of the National Cancer Institute in vitro screen, including cells derived from solid tumors such as non-small cell lung, colon, central nervous system, melanoma, ovarian, prostate and breast cancer, and also few cell lines of leukemia and renal cancer. Introduction of a formyl group at the 5- and substituted aromatic group at 6-position generated compounds with potent antitumor activity. Incorporation of a bromo at 5- and ester group at 6-position produced compounds with reduced activity.