Rapid conversion of glucose to 5-hydroxymethylfurfural using a MoCl3 catalyst in an ionic liquid with microwave irradiation

The efficient conversion of glucose to 5-hydroxymethylfurfural (5-HMF) in ionic liquids with MoCl3 as catalyst under microwave irradiation was demonstrated. Based on 5-HMF yield, the ionic liquid 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) was the best solvent. The results showed that compared to conventional oil-bath heating, microwave irradiation not only reduced the required reaction time from hours to minutes, but also improved the 5-HMF yield. Using 10 mol% of the catalyst, the 5-HMF yield reached 20.61 % at 120 degrees C after 2.5 h with the oil-bath. However, a 5-HMF yield of 27.66 % could be achieved within 5 min when employing 300 W microwave irradiation. Analyses by nuclear magnetic resonance spectroscopy (NMR) and high-performance liquid chromatography-mass spectrometry (HPLC-MS) demonstrated that the coordinate bond interaction between MoCl3/[BMIM]Cl complex and glucose promoted the isomerism of glucose and the dehydration of fructose. Microwave irradiation was also shown to accelerate the bond breaking processes in the reaction.