Heteropolyacid Bisalt of N-octyl Ethoxylated Octadecylamine: An Efficient and Reusable Catalyst for Carboxylic Acid-Free Hydration of Α-Pinene

A series of heteropoly acid bisalts of N-octyl ethoxylated octadecylamine with high acid strength and excellent emulsifying capacity have been prepared via the partial replacement of protons in neat phosphotungstic acid. These ionic liquids exhibit good activity and selectivity in the hydration of α-pinene, even in the absence of a co-catalyst such as chloroacetic acid. The "excellent emulsifying capacity at the reaction temperature and the liquid-liquid separation at room temperature" for the obtained organic heteropolyacid bisalts catalysts enable their easy recovery and reusability, as demonstrated by a six-run recycling test.