Abstract: 7-Hydroxy-4-methylcoumarin was synthesized by Pechmann reaction using ionic liquid 1-methyl-2-pyrrolidinone hydrosulfate as catalyst without solvent. The results showed that 1-methyl-2-pyrrolidinone hydrosulfate could be reused and exhibited excellent catalytic activity. Under the condition as：n(resorcinol)∶n(ethyl acetoacetate)=1∶1.3，1.2%（percent of total mass of reactants） [Hnmp]HSO4，refluxing for 3 h，the yield of 7-hydroxy-4-methylcoumarin is up to 87.24%. Purity of product analyzed by HPLC is above 98.5%.

Key words: 1-methyl-2-pyrrolidinone, hydrosulfate, 7-hydroxy-4-methylcoumarin, synthesis

摘要： 以离子液体N-甲基吡咯烷酮硫酸氢盐为催化剂，通过Pechmann缩合反应于无溶剂条件下合成了7-羟基-4-甲基香豆素，实验表明N-甲基吡咯烷酮硫酸氢盐可重复使用并具有较好的催化活性。在原料摩尔比n(间苯二酚)∶n(乙酰乙酸乙酯)为1∶1.3、催化剂[Hnmp]HSO4占反应物料总质量的1.2%、回流反应时间3 h的条件下，产品收率达87.24%，经液相色谱分析纯度大于98.5%。

关键词: N-甲基吡咯烷酮, 硫酸氢盐, 7-羟基-4-甲基香豆素, 合成