The conversion of glucose into a potential platform chemical for fuels and plastics, 5-hydroxymethylfurfural (HMF), has been studied using B(OH)(3) as a promoter in different solvents, namely molten mixtures made of choline salts and carboxylic acids, with the aim of developing an inexpensive and less harmful alternative to Cr/ionic liquid systems. Choline chloride-based molten mixtures afforded poor yields of HMF, whereas the yields were improved by replacing choline chloride with choline dihydrogen citrate. The combination of choline dihydrogen citrate and glycolic acid was the best choice, providing an HMF yield of similar to 60% at 140 degrees C within 4 h by adding a small volume of water as a co-solvent. (C) 2014 Elsevier Ltd. All rights reserved.