易分离磁性纳米复合固体酸Fe_3O_4@SiO_2-SO_3H催化香豆素衍生物的合成

Synthesis of Coumarin Derivatives Catalyzed by Easily Separable Magnetic Nanocomposite Solid Acid Fe_3O_4@SiO_2-SO_3H

采用共沉淀法制备四氧化三铁,以它做磁性核包覆二氧化硅,进一步磺化得到磺酸基修饰的Fe_3O_4@SiO_2-SO_3H纳米复合材料,将其用于催化合成香豆素衍生物的反应中.采用X射线衍射仪、透射电镜、综合物性测量系统等方法对合成的催化剂进行了表征.通过多元苯酚与取代乙酸乙酯的合成反应,研究了该纳米复合材料的催化活性.结果表明所得五个香豆素衍生物液相收率在89%～96%之间.在不加新催化剂情况下第二次使用催化剂,7-羟基-4-甲基香豆素液相收率为81%.

Ferroferric oxide was prepared with coprecipitation method,which was used as magnetic core coated silica.Fe3O4@SiO2-SO3H nanocomposite was obtained through sulfonation.The catalysts were characterized by x-ray diffractometer,transmission electron microscopy and comprehensive physical property measurement system.Further,the catalyst was used to the synthesis of coumarin derivatives.The catalytic activity of the nanocomposite was compared by the synthesis reaction of polyphenol and substituted ethyl acetate.The results showed that the yield (HPLC) of the five coumarin derivatives was between 89% and 96%.The catalyst was used a second time without the addition of new catalyst,and the yield (HPLC) of 7-hydroxy-4-methylcoumarin was 81%.