无溶剂条件下香豆素类化合物的绿色合成

Green Synthesis of Coumarin under Solvent-free Condition

以乙酰乙酸乙酯和间苯二酚为原料,固体NaHSO_4·H_2O为催化剂,无溶剂条件下通过Pechmann反应合成7-羟基-4-甲基香豆素;并对反应温度、反应时间、催化剂用量、原料配比等因素对产率的影响进行了探究。实验证明,在无溶剂条件下,NaHSO_4·H_2O是合成7-羟基-4-甲基香豆素的良好催化剂,正交实验法得出反应的最优条件为:反应温度为110℃,反应时间40 min,n(间苯二酚)/n(乙酰乙酸乙酯)=1∶1.2,催化剂用量相对于间苯二酚用量的20%mol,产品的收率为81.8%。

Using ethyl acetoacetate and resorcinol as raw materials, NaHSO4·H2O as catalyst, 7-hydroxy-4-methyl coumarin was synthesized by Pechmann reaction under solventless condition. When NaHSO4·H2O was used as catalyst the factors such as reaction temperature, dosage of catalyst, reaction time and the ratio of the raw materials influencing on the yield of the product were discussed. The optimum conditions were established as follows： the molar ratio of ethylacetoacetate to resorcinol was 1.2∶1, the amount of catalyst was relative to the amount of 20% mol of resorcinol, the reaction temperature was 110 ℃, and the reaction time was 40 min. Under the aforementioned conditions, the yield of 7-hydroxy-4-methylcoumarin can reach 81.8%.