Cetrimide-based DES-mediated synthesis of quinoline-appended imidazo[1,2- <i>a</i> ]pyridines and their computational and biological studies

Deep eutectic solvents (DESs) derived from cetrimide and carboxylic acids have been used as a sustainable medium for the synthesis of quinoline-appended imidazo[1,2-<i>a</i>]pyridines through cyclization and C(sp³)-H functionalization. This environmentally friendly strategy promotes high atom economy, eliminates the use of toxic solvents, and supports sustainable synthesis with broad substrate tolerance. Subsequent formylation <i>via</i> the Vilsmeier-Haack reaction further enables selective modifications under the same green conditions. The structural properties were validated by DFT calculations, while biological evaluations revealed notable antibacterial, anticancer, and photophysical activities. The thermal properties, stability, and reusability of the DES system were confirmed through DSC and TGA, reinforcing the method's green credentials and practical relevance in sustainable organic synthesis.