超声辅助快速合成4H-吡喃衍生物

Ultrasonic-assisted Rapid Syntheses of 4H-pyran Derivatives

采用浸渍法制备水滑石(LDH)负载路易斯酸催化剂,并通过傅里叶红外(FT-IR)、热重分析(TG)和扫描电子显微镜(SEM)对其结构进行分析。以芳香醛、丙二腈及苯甲酰乙腈为原料,LDH负载路易斯酸为催化剂,超声辅助快速合成4H-吡喃衍生物。采用单因素法研究了催化剂、溶剂、超声时间、原料摩尔比、催化剂用量、催化剂循环等对产率的影响。结果表明:超声辅助下,LDH/ZnCl_(2)催化5 min即可合成4H-吡喃衍生物(4a~4i),产率82.8%~98.2%;扩大原料用量至克级,4a产率94.6%,且催化剂循环5次仍保持较高的催化性能。

The hydrotalcite(LDH)supported Lewis acid catalyst were prepared by impregnation method,and the structures were confirmed by FT-IR,TG and SEM.4H-pyran derivatives were rapid synthesized using cyano acetophenone,benzaldehyde,malononitrile as raw materials with LDH-supported Lewis acid as catalyst under ultrasonic conditions.Effects of catalysts,solvents,ultrasonic time,molar ratio of raw materials and amount of catalyst on yields were investigated using single factor methods.The results show that:synthesis of 4H-pyran derivatives with LDH/ZnCl_(2)under ultrasonic assisted conditions for 5 min and the yield of 4a~4i compound was 82.8%~98.2%.Increasing the of raw materials to gram grade and 4a yield of 94.6%.The catalyst still maintained high catalytic performance after cycle for five times.