Design, Synthesis, In Silico Profiling, and In Vitro Anticancer Assessment of Azine‐Linked Thiazolo[3,2‐a]benzimidazoles as CDK2‐Directed Therapeutic Candidates

ABSTRACT A series of unsymmetrical azine‐linked thiazolo[3,2‐a]benzimidazole derivatives ( 4a–r ) was synthesized and structurally characterized. Density functional theory (DFT) calculations, including frontier molecular orbital (FMO) analysis and global reactivity descriptors, supported the preferential formation of the E‐isomeric forms. In silico target prediction prioritized cyclin‐dependent kinase 2 (CDK2), and molecular docking of representative active members ( 4b, 4 d, 4p, and 4r ) revealed key contacts around Arg83/Pro84 and favorable binding energies ( − 3.91 to −6.20 kcal/mol). In vitro antiproliferative activity against human colon carcinoma (HCT‐116) and human hepatocellular carcinoma (HepG2) cell lines identified 4r as the most potent compound (half‐maximal inhibitory concentration, IC 50 = 5.26 ± 0.37 and 5.03 ± 0.42 µM, respectively), surpassing doxorubicin (IC 50 = 7.05 ± 0.49 and 6.42 ± 0.31 µM). Absorption, distribution, metabolism, excretion, and toxicity (ADMET) prediction indicated high gastrointestinal (GI) absorption, no blood–brain barrier (BBB) permeation, no P‐glycoprotein (P‐gp) substrate liability, a bioavailability score of 0.55, and zero pan‐assay interference compounds (PAINS) alerts. Overall, the integrated synthetic, computational, and biological results highlight azine‐linked thiazolo[3,2‐a]benzimidazoles, particularly 4r , as promising CDK2‐directed anticancer leads.