Synthesis of 3-Methyl-3-Buten-1-Ol by Supercritical CO2 in Coordination with HZSM-5 Catalyzed Formaldehyde-Isobutene Prins Reaction

The reaction solvent and catalyst play an essential role in the Prins reaction for the synthesis of 3-methyl-3-buten-1-ol (MBO) from formaldehyde and isobutene. The reactivity of the solid base catalyzed Prins condensation reaction by formaldehyde and isobutene in supercritical CO2 was investigated using CsH2PO4 modified HZSM-5. We finds that the alkaline sites of the alkali-loaded catalyst can extract the α-H on isobutene to generate olefin carbon negative ions, while the supercritical CO2 with weak Lewis acidity can activate formaldehyde to carbon positive ions, which can combine more easily with the carbon negative isobutene to react, thus improving the reactivity of the reaction system.