Functionalized magnetic nanoparticles with deep eutectic solvents as efficient catalyst for the green synthesis of...

In this study, deep eutectic solvents were attached to SiO₂-coated magnetic nanoparticles through a linker. The resulting nanomagnet-immobilized arginine/choline chloride designated as MNP@Arg/ChCl was characterized using FT-IR, XRD, TGA, VSM, and SEM techniques. The catalyst showed an irregular spherical morphology, and the mean particle diameter was determined to be about 39.9 nm. TGA analysis also confirmed that the catalyst remained thermally stable up to approximately 225 °C. MNP@Arg/ChCl demonstrated excellent catalytic activity in the solvent-free synthesis of 2,3-disubstituted-2,3-dihydroquinazolin-4(1 H)-one derivatives via a three-component reaction involving isatoic anhydride, amines, and aldehydes. The scope of this method was assessed using various aromatic aldehydes and aromatic amines. The 2,3-disubstituted-2,3-dihydroquinazolin-4(1 H)-one derivatives were obtained in yields ranging from 85% to 93% within a short reaction time. Due to the magnetization properties of MNP@Arg/ChCl, the catalyst can be easily separated from the reaction mixture and reused several times without significant loss of catalytic activity. This method is particularly attractive in the context of green chemistry due to its high catalytic efficiency, thermal stability, reusability, ease of recovery, and environmentally friendly features.