Synthesis, Anticancer Activity, and Computational Studies of Novel Imidazo[1′,2′:1,5]pyrazolo[3,4‐b]pyridine Derivatives

Abstract

A series of novel functionalized pyrazolopyridine derivatives bearing arylidene side chains was synthesized through efficient heterocyclization methods. Additionally, alkyl‐substituted imidazo‐pyrazolopyridine (tetraazacyclopenta[a]indene) compounds and tetracyclic pyrazolopyridine–imidazopyrimidine hybrids (pentaazaindeno[1,2‐a]inden‐2‐one) were prepared. The cytotoxicity of these compounds was assessed against human colorectal (HCT‐116) and breast (MCF‐7) cancer cell lines, revealing that compounds 9 and 16 have exhibited the most potent activity. Other derivatives showed selective cytotoxic effects toward one of the two cell lines. Molecular docking studies were conducted to explore the binding interactions of compounds 9 and 16 within the active site of EGFR (epidermal growth factor receptor). To further investigate the binding stability of compound 16, molecular dynamics (MD) simulations were performed using EGFR (PDB ID: 1M17), providing insight into the stability and structural integrity of the protein‐ligand complex. Additionally, density functional theory (DFT) analysis was carried out to examine the electronic structure of compound 16, including its molecular orbitals and electrostatic potential. The HOMO–LUMO analysis supported the compound's electron‐donating properties, aligning with its strong binding affinity and cytotoxic performance observed in the docking and MD studies.