KF/Al_2O_3合成香豆素-3-羧酸的工艺研究

Catalytio Synthesis of Coumaria-3-Carboxylic Acid by KF/Al_2O_3

以水杨醛、丙二酸二乙酯为原料,KF/Al2O3为催化剂合成了香豆素-3-羧酸乙酯,产物不经分离,直接进行皂化、酸解环合制备香豆素-3-羧酸。采用元素分析、熔点测定、红外光谱(IR)等手段对中间体和产物进行了结构表征。考察了各反应条件对香豆素-3-羧酸收率的影响,确定了最佳工艺条件为:水杨醛4.0g(0.033mol),水杨醛和丙二酸二乙酯物质量比为1.0∶1.2,反应时间100min,香豆素-3-羧酸的收率>85%。

Salicylaldehyde and diethyl malonate were used as raw material to sgnthesize coumarins-3-carboxylate acid.The structure of intermediate product was characterized by FT-IR,melting point and elemental analysis.The optimum conditions were as follows：mol（diethyl malonate）∶ mol（with salicylaldehyde）= 1.0∶1.2,the amount of sodium methoxide 0.6 g,ethanol 20 ml（both salicylaldehyde 4.0 g）,and reaction time 100 min.In those conditions,the yield of coumarin-3-carboxylic acid was more than 85%.