Efficient dehydration of fructose to 5-Hydroxymethylfurfural through triazolium-type ionic liquids

The dehydration of D-fructose to 5-Hydroxymethylfurfural for producing fluid fuels and enhanced-value chemicals had obtained considerable attention. Here, we synthesized the Brønsted-acidic ionic liquids and evaluated the catalytic efficiency in terms of the dehydration of D-fructose. The influence of various factors such as catalyst type, solvents, reaction time, and temperature on the dehydration reaction was investigated. 110 °C, 100 min and Dimethyl sulfoxide (DMSO) as reaction solvents are the best condition for dehydration reactions, achieving a 90% yield of HMF. Notably, the triazolium-based ionic liquids (Tri-ILs) exhibited superior catalytic activity outperforming imidazolium-based ionic liquids (Imi-ILs) under the identical condition. The more acidic C5-H caused by the substitute of carbon by the electron-withdrawing nitrogen atom leaded to the improvement of catalytic performance.