Efficient one-pot production of 5-hydroxymethylfurfural from inulin in ionic liquids

Abstract

An efficient one pot, two-step process was developed for the preparation of 5-hydroxymethylfurfural (5-HMF) from inulin in ionic liquids under mild conditions. In the first step, the ionic liquid 1-butyl-3-methyl imidazolium hydrogen sulfate ([BMIM][HSO₄]) was used as both solvent and catalyst for the rapid hydrolysis of inulin into fructose with 84% fructose yield in 5 min reaction time. In the second step, 1-butyl-3-methyl imidazolium chloride ([BMIM][Cl]) and a strong acidic cation exchange resin were added to the mixture to selectively convert fructose into 5-HMF, giving a 5-HMF yield of 82% in 65 min at 80 °C, which is the highest 5-HMF yield reported by thus far for an inulin feedstock.