微波辅助L-脯氨酸催化Hantzsch反应一锅法合成多氢喹啉

Microwave irradiation assisted L-proline catalyzed one-pot synthesis of polyhydroquinolines via Hantzsch reaction

基于有机小分子L-脯氨酸独特的刚性结构以及在有机转换领域的广泛研究,结合微波辐射技术快速高效等优势,以芳香醛、二甲基环己二酮、β-二酮酯(乙酰乙酸乙酯/苯甲酰基乙酸乙酯)和乙酸铵为原料,乙醇为溶剂,催化剂用量15%,微波功率300 W和80℃的条件下,通过成环缩合的Hantzsch反应一锅法制备得到多氢喹啉类化合物,合成收率达82%~93%。该方法具有条件温和、操作简单以及环境友好等优点。

In view of L-proline as a unique amino acid possessing special rigidity that has been extensively studied in organic transformations,along with the fast and significant efficiency of microwave-promoted in green chemistry,polyhydroquinoline derivatives were synthesized from the aromatic aldehydes with 5,5-dimethylcyclohexane-1,3-dione,β-keto esters(ethyl acetoacetate/ethyl benzoylacetate)and ammonium acetate by one-pot method via Hantzsch reaction under microwave irradiation.The results indicate that the catalyst is efficient with the amount of 15%in solvent of ethanol under irradiation at 300 W with a temperature of 80℃to afford the target products with good yields of 82%-93%.This procedure has the advantages of mild reaction condition,easy work-up and environmentally benign nature.