Ionic liquids via reaction of the zwitterionic 1,3-dimethylimidazolium-2-carboxylate with protic acids. Overcoming synthetic limitations and establishing new halide free protocols for the formation of ILs

M. Smiglak, John Holbrey, S.T. Griffin, W.M. Reichert, Richard Swatloski, A.R. Katritzky, H.F. Yang, D.Z. Zhang, K. Kirichenko, Robin Rogers

Research output: Contribution to journalArticle

76 Citations (Scopus)


The previously reported preparation of 1,3-dimethylimidazolium salts by the reaction of 1,3-dialkylimidazolium-2-carboxylate zwitterions with protic acids has been reinvestigated in detail, leading to the identification of two competing reactions: isomerisation and decarboxylation. The ability to control both pathways allows this methodology to be used as an effective, green, waste-free approach to readily prepare a wide range of ionic liquids in high yields. Additionally, this reaction protocol opens new possibilities in the formation of other imidazolium salts, whose syntheses were previously either very expensive (due to ion exchange protocols involving metals like Ag) or difficult to achieve (due to multiple extractions and large quantities of hard to remove inorganic by-products).
Original languageEnglish
Pages (from-to)90-98
Number of pages9
JournalGreen Chemistry
Issue number1
Publication statusPublished - 2007


Cite this