Efficient Conversion of Monosaccharides into 5-Hydroxymethylfurfural Using Acidic Deep Eutectic Solvents

In this study, a quick, simple, green method of converting carbohydrates into 5-hydroxymethylfurfural (HMF) with the use of deep eutectic solvents (DESs) was reported on. We synthesized 12 DESs for HMF conversion from carbohydrates which were studied under different conditions. Under optimal conditions, oxalic acid and citric acid with a choline chloride-based DES produced a maximum yield of HMF at 59 ± 2% and 62 ± 3% in 5 min at 120 °C, respectively. The efficiency of converting glucose to HMF in a short time (5 min) at 140 °C using CrCl3 with a choline chloride-based DES was around 37 ± 1%, which was higher than in previous work. This study demonstrates the significant potential of DESs as a combination for the continuous catalytic transformation of biomass in the synthesis of platform chemicals.