Direct conversion of inulin to 5-hydroxymethylfurfural in biorenewable ionic liquids

In this work, we found that inulin is soluble in ionic liquids (ILs) choline chloride (ChoCl)/oxalic acid and ChoCl/citric acid, which are prepared entirely from cheap and renewable materials. On the basis of this discovery, we conducted the one pot reaction for the conversion of inulin into 5-hydroxymethylfurfural (HMF), which is a potential substitute for petroleum-based building blocks, using the two ILs as catalysts and solvents. The effects of reaction time, temperature and water added on the reaction were studied. It is demonstrated that the ILs are very efficient for the reaction at relatively lower temperature and could be reused after simple separation.