超声条件下低共熔溶剂中的Biginelli反应

摘要

Nine 3,4-dihydropyrimidin-2(1H)-one derivatives(4a～4i) were synthesized in the pres-ence of deep eutectic solvent, assisting by ultrasonic and using zinc chloride as catalyst.The structures were confirmed by 1H NMR and IR.The reaction conditions, including ultrasonic time, catalyst type and dosage, reaction temperature and molar ratio of raw materials, were optimized using synthesis of 4a as an example.The results indicated that the highest yield of 4a was up to 86.3%under optimal con-ditions[choline chloride/urea as solvent, ZnCl2as catalyst, n(benzaldehyde)( acetoacetic ether) (urea)＝1.0/0.9/1.0, reaction at 90 ℃for 20 min].%在超声辅助下和低共熔溶剂中,使用氯化锌催化Biginelli反应合成了9个3,4-二氢嘧啶-2(1H)-酮衍生物(4a～4i),其结构经1H NMR和IR确证.以4a的合成为例,研究了超声时间、催化剂种类及用量、反应温度和原料摩尔比对反应的影响.结果表明:在最佳反应条件[氯化胆碱/尿素为溶剂,氯化锌作催化剂,n(苯甲醛) (乙酰乙酸乙酯)(尿素)＝1.0/0.9/1.0,于90 ℃反应20 min]下,4a产率最高可达86.3%.