Catalytic conversion of glucose to 5-hydroxymethyl furfural using inexpensive co-catalysts and solvents

► Catalytic conversion of glucose to a platform chemical 5-hydroxymethyl furfural (5-HMF). ► CrCl2 was found to be more active than CrCl3, and other Lewis acids and ultra acids. ► Four cheaper ionic liquids were tested as cocatalysts and solvents for the conversion. ► The optimal yield was achieved at 55% at mild reaction conditions (120-130 °C). ► Reactions in ionic liquids as solvents were faster than in DMSO.