Abstract: An acidic functional ionic liquid 1-(3-sulfonic group)propyl-3-methylimidazole dihydrogen phosphate ((HSO₃-pmim) H₂PO₄) was synthesized and used to catalyze the esterification of terpineol with acetic anhydride. The influences of reaction condition,such as reaction temperature, reaction time, n(terpineol):n(acetic anhydride) and amount of acidic functional ionic liquid were examined. The optimum condition for esterification was obtained as follows:n(terpineol):n(acetic anhydride)1:1.5, terpineol 5.1 g, ionic liquid 1.5 g, reaction temperature 40℃ and reaction time 8 h. Under the above condition, the conversion of terpineol was 100% and the selectivity of terpinyl acetate was 87.2%.The recyclability of the ionic liquid was also investigated. When the ionic liquid was repeatedly used for six times, the conversion of terpineol was 99.4%, and the selectivity of terpinyl acetate was 88.6%.The catalyst for this synthesis has advantages of high yield, simple experimental operation and product isolation, and easy reusability of the catalyst which could be expected to realize an clean and environment-friendly strategy for the production of terpinyl acetate.

Key words: turpentine, acidic functional ionic liquid, terpinyl acetate, esterification