Multicomponent Reaction for the Synthesis of β-Ketosulfides in Deep Eutectic Solvents.

The use of Type III Deep Eutectic Solvents (DESs) as both solvents and cocatalysts enable the one-pot synthesis of several β-ketosulfides, structural motifs commonly found in biologically active compounds, via a multicomponent reaction (MCR) involving 2-bromoketones, alkyl or benzyl halides, and potassium thioacetate in basic medium. Under these conditions, it was possible to avoid not only the use of the non-eco-friendly solvent dimethylformamide (DMF), but also an additional hydrolytic step previously reported for the preparation of these molecules. The MCR conducted in the presence of the DES ChCl:Gly (1:2) was optimized through the evaluation of different reaction parameters. Notably, the non-conventional medium could be recycled up to four times without any appreciable loss of catalytic activity. Environmental metrics, including the E factor, E+ factor, and Global Warming Potential (GWP), were calculated for the process both in the presence and absence of the DES, demonstrating improved environmental performance when the DES was employed.