Optimised microwave-assisted synthesis of methylcarbonate salts: a convenient methodology to prepare intermediates for ionic liquid libraries

• Main Authors: Holbrey, John, Shukla, Saloni, Rogers, Robin
• Format: Article
• Published: Royal Chemical Society 2010
• Subjects: QD Chemistry
• Online Access: http://www.rsc.org; http://eprints.utp.edu.my/719/

The reaction of 1-butylpyrrolidine with dimethyl carbonate to yield the ionic liquid precursor, 1-butyl-1-methylpyrrolidinium methylcarbonate, has been investigated under microwave heating conditions and the reaction parameters optimised to achieve 100% yield of the pyrrolidinium salt with no by-products in under 1 h. The reactions of tributylamine, trioctylphosphine, and 1-butylimidazole with dimethyl carbonate under comparable conditions have also been evaluated, yielding the corresponding methylcarbonate salts which can be used as intermediates for the preparation of halide-free ionic liquids without generating any undesirable salt wastes.