微波辐射合成7-羟基-4-甲基香豆素

Synthesis of 7-Hydroxy-4-Methylcoumarin under Microwave Irradiation

以浓硫酸为催化剂 ,采用微波辐射技术 ,由间苯二酚与乙酰乙酸乙酯缩合制备 7-羟基 - 4-甲基香豆素。结果表明 ,微波辐射合成 7-羟基 - 4-甲基香豆素的最佳反应条件为 :间苯二酚 5 .5 g,乙酰乙酸乙酯 6 .8m l,浓硫酸 1.5 ml,微波功率 2 40 W,微波辐射时间 6 min,产率 84.1%。不采用微波辐射 ,反应时间大于 10 h,产率78%。红外光谱分析表明 ,7-羟基 - 4-甲基香豆素的特征峰与 7-羟基 - 4-甲基香豆素的各官能团的吸收峰吻合 ,测定 7-羟基 - 4-甲基香豆素的熔点为 189～ 192℃。

The synthesis of 7 hydroxy 4 methylcoumarin is performed by the condensation of 1,3 benzenediol and ethyl acetoacetate under microwave irradiation The optimum reaction conditions are as follows:5 5 g 1,3 benzenedol,6 8 ml ethyl acetoacetate,1 5 ml concentrated sulfuric acid, 240 W microwave power and 6 min microwave irradiation The yield reachs 84 1% In the non irradiated conditions, the yield is 78% ,and the reaction time is over 10 h IR spectra indicates that the characteristic peaks of 7 hydroxy 4 methylcoumarin are in line with the absorption peaks of other functional groups The melting point of 7 hydroxy 4 methylcoumarin is 189℃ to 192℃