Effective 5-Hydroxymethylfurfural Production in Piperylene Sulfone, a Recyclable Solvent

We present an optimized reaction for the production of high yields of 5-hydroxymethylfurfural (5-HMF) from fructose using piperylene sulfone as a sustainable solvent. 5-HMF is a high value chemical with a wide spectrum of applications spanning from medical research to biofuels. Currently, it is produced from fructose using dimethylsulfoxide (DMSO) as the solvent. Although yields of >85 % can be obtained, it is an energy intensive process that generates large waste streams, mostly due to the high boiling point and poor recyclability of DMSO. To address these shortcomings, we implemented piperylene sulfone as an alternative solvent. Piperylene sulfone has similar solvatochromic properties and dielectric constants to DMSO, making it a viable replacement as a reaction medium. In contrast with DMSO, however, piperylene sulfone is a switchable solvent. As a result, it has the ability to reversibly decompose at with mild heating into sulfur dioxide and piperylene, allowing for facile separation of solvent. Post-separation, piperylene and sulfur dioxide can be recombined to reform piperylene sulfone and allowing for full recyclability of the solvent.

We demonstrate the reaction from fructose in piperylene sulfone with Amberlyst-15 as catalyst and the subsequent 5-HMF separation. We will present the results of a statistical design of experiments conducted to optimize conversion of 5-HMF. Additionally, we will demonstrate the successful separation of 5-HMF from the switchable solvent, piperylene sulfone.