Background: Due to the importance of 1,3,4-thiadiazoles and phthalimides in anticancer agents, a novel series of 1,3,4-thiadiazole-phthalimide system have been synthesized and evaluated in vitro against HT-29 and MCF-7 human cancer cell lines.

Methods: The target compounds were prepared through four-step reaction and their cytotoxicities were evaluated by MTT assay.

Results: The results showed that 4-nitrobenzoyl moiety containing derivatives are the most potent ones. The morphological evaluation also indicated that these compounds are apoptotic inducers.

Conclusion: 4-Nitro-N-(5-((3-(1,3-dioxoisoindolin-2-yl)propyl)thio)-1,3,4-thiadiazol-2-yl)benzamide (8m) exhibits the best inhibitory effect against HT-29 and MCF-7 cell lines with IC50 values of 23.83 and 27.21 μM, respectively.