Catalyst-Free, Visible-Light-Triggered One-Pot Formation of Imidazole N -Oxide Derivatives in H 2 O/EtOH Medium: Investigation of Their Therapeutic Properties

High Resolution Image Download MS PowerPoint Slide An innovative, astonishing, and nonphotocatalytic visible-light-mediated synthesis of imidazole N -oxide derivatives has been established in aqueous ethanol via formation of an electron donor–acceptor (EDA) complex under mild, sustainable conditions. UV–visible spectroscopy analysis verified the production of the EDA complex, while the cyclic voltammetry (CV) experiment showed the oxidizing and reducing nature of the reactants. The stoichiometric ratio of the donor and acceptor compounds in the EDA complex was estimated using Job’s plot, and the binding constant was estimated using the modified Benesi–Hildebrand equation. Mechanistic investigations and control experiments revealed a radical route, which was confirmed by TEMPO radical trapping tests, and the conversion of reactants to radical-trapped adducts was investigated using high-performance liquid chromatography (HPLC) analysis. The electrical properties and charge-transfer characteristics of the EDA complex were further confirmed by theoretical studies by applying TD-DFT calculations. This approach encouraged the synthesis of 56 imidazole N -oxide derivatives with acceptable to exceptional yields (up to 98%). The usefulness of the method was demonstrated by gram-scale synthesis, which yielded the desired product in 72% yield, and by scale-up experiments that examined yield variance across mmol-scale reactions. Green chemistry parameters were also determined, suggesting that this method generates fewer waste products and is more environmentally friendly. The preliminary biological evaluation of the produced compounds revealed that various derivatives have significant antioxidant, antidiabetic, and anti-inflammatory properties. Furthermore, cytotoxicity investigations against the WRL-68 cell line revealed that certain compounds have low cytotoxicity, indicating possible biological compatibility.