微波辐射下磺酸基功能化离子液体无溶剂催化合成4-甲基香豆素及其衍生物

Synthesis of Coumarin Derivatives Under Microwave Irradiation and Solvent-free Condition Catalyzed by SO_3H Functionalized Ionic Liquid

研究了3种磺酸基功能化离子液体催化香豆素及其衍生物的合成,取代酚与乙酰乙酸乙酯在无溶剂微波辐射条件下,通过Pechmann缩合反应,合成了一系列4-甲基香豆素衍生物,探讨了反应时间、反应温度、催化剂用量、离子液体重复使用性能诸因素对产品产率的影响。结果表明,离子液体[C3SO3Hmim]HSO4是合成目标产物的良好催化剂,微波辐射时间10 min,反应温度100℃,n(酚)∶n(乙酰乙酸乙酯)=1∶1,催化剂用量x([C3SO3Hmim]HSO4)=20%时,最高产率可达94%。该法反应条件温和,操作简便,产物易分离,产率高,环境友好,离子液体可重复使用4次。

The coumarin derivatives of phenols and ethyl acetoacetate were synthesized via Pechmann condensation using SO3 H functionalized ionic liquid as catalyst. The optimum reaction conditions were as follows ： n （phenols） ： n （ ethyl acetoacetate） = 1 ： 1, microwave irradiation reaction time 10 minute and reaction temperature 100 ℃. The highest yield can reach 94% in the presence of x （[ C3SO3Hmim] 1-ISO4 ） = 20% as catalyst and under solvent-free conditions. This method has the advantages of mild reaction conditions, easy operation, high yields and being environmentally benign. Moreover, catalyst could be reused for at least four times.