Synthesis and cytotoxic evaluation of novel brominated N-alkyl pyrano[3,2-c]quinolinones

A novel series of 6-alkyl-4-bromopyrano[3,2-c]quinoline-2,5-diones (2a-c), 6-alkyl-3,4-dibromopyrano[3,2-c]quinoline-2,5-diones (4a-c), and 6-alkyl-3-amino-bromopyrano[3,2-c]quinoline-2,5-diones (6a-c) were synthesized via appropriate conventional methods and in good yields. The structures of target compounds were approved by elemental analysis, IR, H-1 NMR, C-13 NMR, and mass spectrometry. The antitumor inhibitory activities of the new compounds were evaluated on several cancer cell lines, A-549 (human lung cancer), HCT-116 (human colon cancer), MCF-7 (breast cancer), and HePG-2 (human liver cancer). Moreover, 50% inhibitory concentrations, IC50, were established. 5-Fluorouracil was used as a positive control in the viability assay. The screening results showed that most of the examined compounds exposed powerful inhibition activity toward various cell lines. Particularly, Compound 4c exhibited higher cytotoxic activity against four tumor cell lines than the reference drug, 5-fluorouracil, with significantly lower IC50 values. Accordingly, most of the synthesized compounds would be a better prospective growth in the anticancer drug discovery.