Design, Synthesis, and Biological Evaluation of N,N-Diphenylaniline-Based Derivatives as Antiproliferative Agents and ABL TK Inhibitors Against CML

Background/Objectives: Targeting ABL tyrosine kinase (TK) remains a cornerstone of chronic myeloid leukemia (CML) therapy. Methods: In this study, a series of novel 4-((2-(4-(aryl)thiazol-2-yl)hydrazineylidene)methyl)-N,N-diphenylaniline derivatives (1–12) were synthesized through the reaction of 2-(4-(diphenylamino)benzylidene)hydrazine-1-carbothioamide (intermediate A) with substituted 2-bromo-1-arylethanones. Cytotoxic activity was evaluated in K562 CML cells using the MTT assay. The most active compound was further assessed in HL-60 acute myeloid leukemia (AML) cells and healthy peripheral blood mononuclear cells (PBMCs). Apoptosis induction was analyzed by Annexin V/ethidium homodimer staining, while ABL TK inhibition was determined using the ADP-Glo kinase assay. Molecular docking studies were performed to investigate binding interactions within the ATP-binding site of ABL TK, and pharmacokinetic properties were also predicted. Results: Intermediate A demonstrated superior antiproliferative activity compared to derivatives 1–12 and exhibited cytotoxicity comparable to imatinib in K562 cells (IC50 = 6.15 ± 1.26 µM vs. 5.14 ± 1.44 µM, respectively). In HL-60 cells, intermediate A showed an IC50 of 12.04 ± 1.70 µM, similar to imatinib. Notably, intermediate A displayed enhanced selectivity toward K562 cells over PBMCs (SI = 12.9) relative to imatinib (SI = 6.2). The compound significantly induced apoptosis in K562 cells and inhibited ABL TK activity. Docking studies revealed a distinct binding orientation within the ATP-binding pocket of ABL TK. The compound showed acceptable predicted physicochemical and ADME characteristics based on in silico analysis. Conclusions: Intermediate A emerges as a significant anti-CML candidate exhibiting potent cytotoxic, apoptotic, and moderate ABL TK inhibitory activity, together with a favorable selectivity profile.