Dehydration of glucose to 5-hydroxymethylfurfural and 5-ethoxymethylfurfural by combining Lewis and Bronsted acid

In this work, glucose was transformed into 5-hydroxymethylfurfural (HMF) and 5-ethoxymethylfurfural (EMF) in the presence of AlCl3 center dot 6H(2)O and a Bronsted solid acid catalyst (PTSA-POM). GVL (gamma-valerolactone)-water and ethanol-water solvent systems were evaluated in the dehydration reaction of glucose into HMF and EMF, respectively. Water content and dosage of AlCl3 center dot 6H(2)O were examined in the conversion of glucose into HMF, and some valuable chlorides (FeCl3 center dot 6H(2)O, NiCl2 center dot 6H(2)O, CrCl3 center dot 6H(2)O etc.) were also used in contrast with AlCl3 center dot 6H(2)O. Some different organic solvents were added to the ethanol-water system to explore whether it would be beneficial to the generation of EMF. A high yield of HMF (60.7%) was obtained at 140 degrees C within 60 min in GVL-water (10:1) solvent system, and total yield 42.1% of EMF and HMF (30.6% EMF, 11.5% HMF) was achieved at 150 degrees C after 30 min in an ethanol-water (9 : 1) solvent system.