Use of Microwave Irradiation and Solid Acid Catalysts in an Enhanced and Environmentally Friendly Synthesis of Coumarin Derivatives
作者:Antonio de la Hoz、Andrés Moreno、Ester Vázquez
DOI:10.1055/s-1999-2674
日期:1999.5
Condensation of phenol, 1,3-dihydroxybenzene and 1,3,5-trihydroxybenzene with propynoic and propenoic acids and ethyl acetoacetate using solid acid catalysts and microwave irradiation produces coumarins in excellent yields. The use of hterogeneous catalystas eliminates the production of acidic waste streams associated with conventional (Lewis) acid catalysts. This quick, efficient and environmentally friendly procedure permits the synthesis of substituted coumarins as well as coumarins without 4-alkyl substituents, which are the most difficult to synthesize.
使用固体酸催化剂和微波辐照,将苯酚、1,3-二羟基苯和 1,3,5-三羟基苯与丙炔酸、丙烯酸和乙酰乙酸乙酯进行缩合,可生产出产率极高的香豆素。使用均相催化剂可避免产生与传统(路易斯)酸催化剂相关的酸性废液。这种快速、高效和环保的方法可以合成取代香豆素和不含 4-烷基取代基的香豆素,而 4-烷基取代基是最难合成的。