Microwave-promoted conversion of concentrated fructose into 5-hydroxymethylfurfural in ionic liquids in the absence of catalysts

Microwave-promoted conversion of concentrated fructose into 5-hydroxymethylfurfural in ionic liquids in the absence of catalystsUnder microwave irradiation, concentrated fructose (33-92 wt%) in ionic liquids afforded 5-hydroxymethylfurfural in ca. 97-57% yields without addition of catalysts, within 3 min. In-situ (13)C NMR and (1)H NMR spectra suggest that the transformation of fructose in ionic liquid is a highly selective reaction that proceeds predominantly via the cyclic fructofuransyl intermediate. This method is expected to be valuable in facilitating cost-effective conversion of carbohydrates into biofuels and platform chemicals. (C) 2011 Elsevier Ltd. All rights reserved