One pot conversion of fructose to alkyl levulinates catalyzed by deep eutectic solvents in microwave reactor

Abstract

The conversion of biomass into valuable chemicals has emerged as a promising alternative to replace the current manufacturing of products derived from petroleum feedstocks. Methyl and ethyl levulinate are important chemicals derived from biomass, and they have the potential to be converted into other useful molecules. This work revealed the capability of acidic deep eutectic solvents (DES) to convert fructose into alkyl levulinates. DESs have attracted significant interest owing to their exceptional characteristics and broad variety of practical applications. Fructose conversion was conducted using ChCl-pTSA and ChCl-OxAc deep eutectic solvents, which possess high Brønsted acidity. The results indicated that ChCl-pTSA provided complete transformation of fructose and high yields of ethyl levulinate (59.2 %) and methyl levulinate (76.3 %) under optimal conditions within 20 min. An investigation was conducted to examine the influence of temperature and reaction duration on the one pot approach to converting fructose into alkyl levulinates. The synthesis of alkyl levulinate was increased by increasing the temperature and reaction duration, up to certain critical values.