Novel basic ionic liquids from cyclic guanidines and amidines - new catalysts for transesterification of oleochemicals

BACKGROUNDAlkylguanidinium and alkylamidinium hydroxides have been developed as new basic ionic liquids for the first time from cyclic guanidine (TBD) and amidines (DBN, DBU). The method of preparation of [bmim]OH decribed in the literature was adopted for the synthesis of new ionic liquids. Synthesis was carried out using cyclohexane as the solvent for the synthesis of alkylguanidine and alkylamidine bromides. Anion metathesis was carried out over anionic resins in water as solvent. The structures of the new ionic liquids were confirmed by spectral analysis. The catalytic activity of the new ionic liquids was tested in transesterification of fatty acid methyl esters with trimethylolpropane, neopentyl glycol and 2-ethylhexyl alcohol. RESULTSThe new ionic liquids have good thermal stability and can be applied for transesterification processes. The highest conversion of FAME (83%) was obtained for TMP ester of oleic acid and ionic liquid [TBD-Bu]OH. CONCLUSIONAmong the ionic liquids derived from cyclic guanidine and amidine only ionic liquids obtained from TBD are good catalysts for transesterification of FAME and polyols. In comparision with [bmim]OH, catalytic activity of TBD ionic liquids was comparable in the synthesis of TMP ester but better in the synthesis of 2EH esters. (c) 2013 Society of Chemical Industry