Tandem grinding reactions involving aldol condensation and Michael addition in sequence for synthesis of 3,4,5-trisubstituted isoxazoles
作者:Xiao-Mu Hu、Hai Dong、Yue-Dan Li、Ping Huang、Zhuang Tian、Ping-An Wang
DOI:10.1039/c9ra04864b
日期:——
A one-pot, base-catalyzed, tandem grinding process involving carrying out aldol condensation and Michael addition in sequence to produce 3,4,5-trisubstituted isoxazoles from 3,5-dimethyl-4-nitroisoxazole, aromatic aldehydes and activated methylene compounds has been developed. In the presence of 10 mol% of pyrrolidine, aldol condensations of 3,5-dimethyl-4-nitroisoxazole with various aromatic aldehydes
一种一锅、碱催化、串联研磨工艺,包括依次进行醇醛缩合和迈克尔加成,由3,5-二甲基-4-硝基异恶唑、芳香醛和活化的亚甲基化合物生产3,4,5-三取代异恶唑,已开发。在 10 mol% 吡咯烷存在下,3,5-二甲基-4-硝基异恶唑与各种芳香醛进行羟醛缩合,研磨 3-10 分钟,得到良好的 5-苯乙烯基-3-甲基-4-硝基异恶唑。无需进一步纯化即可达到定量收率。然后,在 10 mol% Et 3 N 存在下,在同一研钵中进行 5-苯乙烯基-3-甲基-4-硝基异恶唑与活化亚甲基化合物(包括 2-硝基乙酸乙酯和 2-氰基乙酸烷基酯)之间的迈克尔加成反应。连续研磨 3-5 分钟即可以良好至优异的产率生产 3,4,5-三取代异恶唑。