Various carbohydrate precursors dehydration to 5-HMF in an acidic biphasic system under microwave heating using betaine as a co-catalyst

A mixture of betaine–formic acid was employed to convert d-glucose and d-fructose into 5-hydroxymethylfurfural (5-HMF) with high selectivity and also for the direct conversion of water-soluble starch and microcrystalline insoluble cellulose. The reactions were performed in average of temperature found between 160 and 200 °C regarding the nature of the substrate. The reactions were carried out under microwave heating and performed in a water–MIBK biphasic system at different ratios. In each case, the specific optimized condition gave values of HMF yields of 82%, 55%, 54% and 47% respectively from d-fructose, d-glucose, water-soluble starch and cellulose microcrystalline powder.