Sugar-based natural deep eutectic solvent immobilized on Fe3O4 magnetic nanoparticles for one-pot synthesis of xanthene derivatives

Xanthene compounds have garnered considerable attention in the fields of organic chemistry and medicinal science owing to their broad spectrum of biological activities, including antibacterial, antiviral, anti-inflammatory, and photochemical properties. The efficient synthesis of these compounds under mild conditions remains a significant challenge in the context of green chemistry. The application of nanocatalysts, particularly those employing magnetic supports such as Fe 3 O 4 , represents a promising strategy for facilitating condensation reactions, attributed to their facile recovery, high thermal stability, and favorable product yields. In this work, a rapid, straightforward, and highly efficient one-pot protocol was developed under solvent-free conditions for the green synthesis of xanthene derivatives, employing a magnetic nanocatalyst based on a natural deep eutectic solvent (Fe 3 O 4 @(mannose:urea)). The structural and physicochemical characteristics of the synthesized nanocatalyst were thoroughly investigated using FT-IR, TEM, FE-SEM, EDX, elemental mapping, XRD, and TGA analyses. The proposed methodology offers several notable advantages, including the use of readily available starting materials, straightforward product isolation from the reaction mixture, enhanced product yields, reduced reaction times, operational simplicity, and the recyclability of the catalyst. This catalytic system affords good to excellent yields (78–98%) within short reaction times (20–60 min) under mild conditions and can be successfully reused for up to five consecutive cycles without any appreciable loss of catalytic activity.