| Title: | Choline Chloride-Based Deep Eutectic Solvents as Green Effective Medium for Quaternization Reactions |
| Author(s): | Busic V; Molnar M; Tomicic V; Bozanovic D; Jerkovic I; Gaso-Sokac D; |
| Address: | "Department of Applied Chemistry and Ecology, Faculty of Food Technology Osijek, Josip Juraj Strossmayer University of Osijek, 31000 Osijek, Croatia. Faculty of Chemistry and Technology, University of Split, 21000 Split, Croatia" |
| DOI: | 10.3390/molecules27217429 |
| ISSN/ISBN: | 1420-3049 (Electronic) 1420-3049 (Linking) |
| Abstract: | "The Menshutkin reaction represents the alkylation of tertiary amines by alkyl halide where the reactants are neutral and the products, quaternary ammonium salts, are two ions with opposite signs. The most commonly used organic solvents in quaternization reactions are volatile organic solvents (VOSs), namely acetone, anhydrous benzene, dry dichloromethane (DCM), dimethylformamide (DMF) and acetonitrile (ACN). The purpose of this work was to examine eutectic solvents as a 'greener' alternative to conventional solvents so that quaternization reactions take place in accordance with the principles of green chemistry. Herein, sixteen eutectic solvents were used as replacements for volatile organic ones in quaternization reactions of isonicotinamide with substituted phenacyl bromides. The reactions were carried out at 80 degrees C by three synthetic approaches: conventional (4-6 h), microwave (20 min) and ultrasound (3 h). Microwave-assisted organic reactions produced the highest yields, where in several reactions, the yield was almost quantitative. The most suitable eutectic solvents were based on choline chloride (ChCl) as the hydrogen bond acceptor (HBA) and glycerol, oxalic or levulinic acid as hydrogen bond donors (HBDs). The benefits of these three deep eutectic solvents (DESs) as a medium for quaternization reactions are the simplicity of their preparation for large-scale production, with inexpensive, available and nontoxic starting materials, as well as their biodegradability" |
| Keywords: | *Choline/chemistry *Deep Eutectic Solvents Solvents/chemistry Glycerol/chemistry Hydrogen Bonding deep eutectic solvents isonicotinamide salts microwave synthesis ultrasound synthesis; |
| Notes: | "MedlineBusic, Valentina Molnar, Maja Tomicic, Vice Bozanovic, Dalia Jerkovic, Igor Gaso-Sokac, Dajana eng UIP-2017-05-6593/Croatian Science Foundation and the Green Technologies in Synthesis of Heterocyclic Compounds Project/ Switzerland 2022/11/12 Molecules. 2022 Nov 1; 27(21):7429. doi: 10.3390/molecules27217429" |
