Design, synthesis and biological evaluation of some novel benzthiazole containing 4H-chromene-4-one derivatives

Chromene derivatives are gaining attention in the pharmaceutical industry, while substituted benzothiazole derivatives have shown potential in various therapeutic areas, including anti-ulcer, anti-hypertensive, anti-viral, anti-fungal, anti-cancer, and anti-histaminic treatments. Benzimidazole derivatives, when combined with other heterocyclic compounds such as pyrazole, thiadiazole, triazole, thiazole, coumarin, and 2-azetidinone, exhibit a wide range of pharmacological properties. In our research, we developed novel 2-(2-(5-nitro-1H-benzo[d]thiazol-2-yl)vinyl)-4H-chromen-4-one derivatives through a reaction involving 2-methyl-1H-benzo[d]thiazole and substituted chromone-3-carbaldehyde in the presence of glacial acetic acid (GAA). The synthesized compounds were characterized using techniques such as IR spectroscopy, ¹H NMR, ¹³C NMR, mass spectrometry, and elemental analysis. Their in-vitro anti-cancer activity was assessed against the A-549 human cancer cell line using the SRB assay method. Among the tested compounds, R1 and R6 demonstrated significant inhibitory activity, reducing cell growth by 21.9% and 39.4%, respectively, at a concentration of 80μg/mL, while other derivatives allowed 57–94% cell growth. The biological activity was influenced by the substitutions on the coumarin nucleus, with unsubstituted (R4), fluoro-substituted (R6), and chloro-substituted (R1) coumarin derivatives showing notable potency.