Synthesis of 5-ethoxymethylfurfural from saccharides using combined metal–surfactant catalyst in ethanol/dimethyl sulfoxide

The synthesis of 5-ethoxymethylfurfural (EMF) from glucose using metal chlorides or combined metal–surfactant catalysts as Lewis acids in a solution of ethanol/dimethyl sulfoxide was investigated. Metal chlorides such as aluminum chloride and chromium(III) chloride mainly produced 5-hydroxymethylfurfural and ethyl glucoside in reactions at 140 °C for 180 min. However, the combined metal–surfactant catalysts aluminum tridodecyl sulfate (Al(DS)3) and chromium(III) tridodecyl sulfate efficiently improved the yield of EMF from glucose. The maximum yield of EMF using Al(DS)3 was 37.9% at 160 °C for 60 min. Moreover, the EMF yields from other saccharides (fructose, mannose, sucrose, cellobiose, and inulin) in the presence of Al(DS)3 as a catalyst ranged from 31.2 to 59.3%.