Reaction network analysis and continuous production of isosorbide tert-butyl ethers

Isosorbide is considered a versatile biogenic platform compound for the production of chemicals. The functionalization of its two hydroxyl groups is challenging since they exhibit a different configuration and thus, different reactivity as well as sterical accessibility. We investigated the formation of the respective tert-butyl ethers by an addition reaction of isosorbide to isobutene heterogeneously catalyzed by acidic ion exchange resins. An efficient liquid phase process under ambient conditions in a batch reactor has been developed. The reaction network was unravelled by detailed investigation of the reaction kinetics. Additionally, the feasibility of continuous processing was successfully demonstrated on the lab-scale applying a continuously stirred-tank reactor.