processes for producing 5 - furfural are provided . 5 - furfural is a potential platform intermediate in the conversion of biomass to renewable chemicals . the processes use hexoses in an aqueous solution comprising a halide - containing salt , a water - miscible organic solvent , acid , and water providing an aqueous solution comprising a halide - containing salt , a water - miscible organic solvent , acid , and water . the use of small amounts of halide - containing salt results in significant increases in yield .