超声辅助水滑石/ZnCl2高效催化Knoevenagel缩合反应

Ultrasound-assisted hydrotalcite/ZnCl catalytic Knoevenagel condensation

以芳香醛、丙二腈为原料,水滑石(LDH)/ZnCl2为催化剂,室温下超声辅助Knoevenagel反应。筛选催化剂及催化剂用量、溶剂、反应时间、原料物质的量比对产率的影响,产物结构经1H NMR、IR、MP确证。结果表明,水滑石/ZnCl2可以在中性条件下高效催化Knoevenagel缩合反应。该方法操作简单、速度快,室温下超声5 min即可完成,合成3a^3i的化合物的产率为85.5%~99.3%。扩大苯甲醛和丙二腈的用量至克级,产率为94.1%,说明该催化剂对于该反应有较好的工业发展潜力。

Aromatic formalin and malononitrile were used as raw materials,hydrotalcite(LDH)/ZnCl2 was used as catalyst.The effects of catalyst and catalyst dosage,solvent,reaction time and raw material ratio on the yield were investigated by ultrasonic assisted reaction at room temperature.The structure of the product was characterized by 1H NMR,IR and MP.The results show that hydrotalcite/ZnCl2 can efficiently catalyze the Knoevenagel condensation reaction without the aid of alkali.The method is simple and fast,and can be completed by ultrasonication at room temperature for 5 min.The yield of the compound synthesized from 3 a^3 i is 85.5%~99.3%.The amount of benzaldehyde and malononitrile was increased in a yield of 94.1%,indicating that the catalyst has a good industrial development potential for the reaction.