Abstract Levulinic acid is a cellulose‐derived sustainable feedstock with potential applications in renewable carbon‐based polymer and chemical synthesis. Direct chlorination of levulinic acid using chlorine gas was investigated as an activation strategy for ether formation and alkylation reactions. Chlorination was examined in nonpolar and polar solvents, including n ‐pentane, methylene chloride, diethyl ether, dioxane, and water, at 0–23 °C by bubbling chlorine gas through the reaction mixture. Using 4.5 equivalents of chlorine gas in methylene chloride at 0 °C resulted in the highest levulinic acid conversion (92%), producing a mixture of 5‐chlorolevulinic acid and 3‐chlorolevulinic acid in a 1:3.9 molar ratio. Increasing solvent polarity reduced the proportion of 3‐chlorolevulinic acid, with 5‐chlorolevulinic acid becoming the dominant product in diethyl ether and aqueous media. As an application, the chlorolevulinic acid isomer mixture obtained with 4.5 equivalents of chlorine gas was used to prepare sodium levulinate cellulose with a degree of substitution of 1.09 in a 92% yield.
Amarasekara et al. (Thu,) studied this question.