Synthesis and anticancer activities of some novel 2-(benzo[d]thiazol-2-yl)-8-substituted-2H-pyrazolo[4,3-c]quinolin-3(5H)-ones

A series of 2-(benzo[d]thiazol-2-yl)-8-substituted-2H-pyrazolo[4,3-c]quinolin-3(5H)-ones (3a–g) have been synthesized and evaluated for their in vitro antiproliferative activities against four human cancer cell lines: MDA-MB-435 (breast), HL-60 (leukemia), HCT-8 (colon) and SF-295 (central nervous system). The results showed that the compounds 3b (2-(benzo[d]thiazol-2-yl)-8-methyl-2H-pyrazolo[4,3-c]quinolin-3(5H)-one) and 3c (2-(benzo[d]thiazol-2-yl)-8-bromo-2H-pyrazolo[4,3-c]quinolin-3(5H)-one) exhibited good cytotoxicity for three cell lines with IC50 values lower than 5 μg/mL. Analysis of theoretical toxicity risks have shown medium tumorigenic and irritant risks related to 3b and 3c in contrast to doxorubicin, the positive control.

Graphical abstractSynthesis and anticancer activities of a novel series of 2-(benzo[d]thiazol-2-yl)-8-substituted-2H-pyrazolo[4,3-c]quinolin-3(5H)-ones are reported.Figure optionsDownload full-size imageDownload as PowerPoint slideResearch highlights► Pyrazolo[4,3-c]quinolin-3-ones with a benzothiazole moiety as potential antitumorals. ► Pyrazolo[4,3-c]quinolin-3-ones with a benzothiazole core may have a good oral biodisponibility. ► Pyrazolo[4,3-c]quinolin-3-ones with a benzothiazole core with medium tumorigenic and irritant risks.