Catalytic conversion of carbohydrates to 5-hydroxymethylfurfural promoted by metal halides

The promotion effect of alkali metal halides toward the AlCl 3 -catalyzed conversion of glucose to 5-hydroxymethylfurfural (HMF) was investigated. The results show that NaF inhibited the reaction. However, NaI and NaBr promoted the reaction significantly, and the promotion effect of NaI was more obvious than that of NaBr. In N , N -dimethylacetamide (DMAC), when NaI was used as an additive for the AlCl 3 -catalyzed conversion of glucose at 130 °C for 15 min, glucose conversion increased from 71% to 86%, and the HMF yield increased from 36% to 62%. The AlCl 3 -NaI-DMAC system could also be used for the catalytic conversion of other carbohydrates such as fructose, mannose, sucrose, maltose , cellobiose, and inulin to HMF. When sucrose was used as the feedstock, a 63% HMF yield was achieved.