Synthesis of Aryl‐Functionalized Benzo[d,e]Benzo[4,5]İmidazo[2,1‐a]Isoquinolin‐7‐One Derivatives: DNA Intercalation Causing Cytotoxicity

Abstract This study focuses on the cytotoxic effect properties of 4‐aryl‐functionalized benzo[ d,e ]benzo[4,5]imidazo[2,1‐ a ]isoquinolin‐7‐one ( 4‐X−Ar−BBI ). The electron‐withdrawing and electron‐donating substituents located at the para position of the phenyl ring attached to the heterocyclic structure have altered the pi electron density within the structure. This change in electron density has influenced the intercalation ability of the heterocyclic structure and has impacted the intensity of its interaction with DNA. The 4‐aryl‐benzo[ d,e ]benzo[4,5]imidazo[2,1‐ a ]isoquinolin‐7‐one derivatives ( 4‐X−Ar−BBI ) were prepared via the Suzuki–Miyaura cross‐coupling reaction. The optimum reaction conditions were determined to be 70 °C for 5 hours using catalyst 1 and K 2 CO 3 , resulting in a yield of 96 % of 4‐H−Ar−BBI . Characterization of all compounds ( 4‐X−Ar−BBI ) was performed using Fourier Transform Infrared spectroscopy, mass spectrometry, and 1 H‐ and 19 F‐NMR spectroscopies. The cytotoxic activities of the compounds ( 4‐X−Ar−BBI ) were investigated against cancer cell lines, specifically HeLa (human cervix adenocarcinoma epithelial), PC3 (human prostate), and MCF‐7 (human breast). The stability of 4‐CN−Ar−BBI and the binding modes between 4‐CN−Ar−BBI and DNA were investigated via 1 H‐NMR spectroscopy and UV‐Vis spectroscopy, respectively. 4‐CH 3 −3‐NO 2 −Ar−BBI exhibited the most potent cytotoxic activity against MCF‐7, and 4‐F−Ar−BBI showed the highest activity against HeLa, with IC 50 values of 3.675 and 7.370 μM, respectively.