采用两步法合成了[MPSIm][HSO₄]、[EPSIm][HSO₄]、[BPSIm][HSO₄]、[HPSIm][HSO₄]、[MPSIm][H₂PO₄]和[MPSIm][pTS]6种Brønsted酸性离子液体，分别考察了其在酯化合成2，6-萘二甲酸二甲酯（2，6-NDC）过程中的催化性能。结果表明，[MPSIm][HSO₄]的催化活性最高；当采用[MPSIm][HSO₄]催化剂时，在反应温度为137℃、反应时间为4 h、醇酸质量比为7.5：1和催化剂质量为甲醇质量2%的条件下，2，6-NDA的转化率达到99.1%，2，6-NDC的收率达到92.9%，且催化剂循环使用10次，[MPSIm][HSO₄]的催化活性并没有显著下降。与传统硫酸催化剂相比，[MPSIm][HSO₄]显著降低了甲醇醚化的副反应。

Six kinds of Brønsted acidic ionic liquids (BILs),including [MPSIm] [HSO₄], [EPSIm] [HSO₄], [BPSIm] [HSO₄], [HPSIm] [HSO₄], [MPSIm] [H₂PO₄] and [MPSIm] [pTS],are synthesized by two-step method.Their catalytic performance is evaluated in synthesis of dimethyl 2,6-naphthalate through esterification process.It is found that [MPSIm] [HSO₄] shows the highest catalytic activity among six BILs.The conversion rate of 2,6-naphthalene dicarboxylic acid and the yield of dimethyl 2,6-naphthalate can reach 99.1% and 92.9%,respectively,under the optimum reaction conditions that the temperature is at 137℃,reaction lasts for 4 h,the mass ratio of methanol to 2,6-naphthalene dicarboxylic acid is 7.5:1 and the dosage of [MPSIm] [HSO₄] catalyst is 2 wt% of the mass of methanol.The catalytic activity of [MPSIm] [HSO₄] has no significant drop after being reused for ten times.Moreover,comparing with traditional catalyst H₂SO₄, [MPSIm] [HSO₄] can obviously inhibit the side reaction of methanol etherification.