申请人:FMC Corporation
公开号:US04081488A1
公开(公告)日:1978-03-28
1,1-Dihalo-4-methyl-1,3-pentadienes, key intermediates in the syntehsis of insecticidal dihalovinylcyclopropanecarboxylates, may be prepared in three steps beginning with the Friedel Crafts condensation of a vinylidene halide and an isobutyryl halide in the presence of a Lewis acid catalyst, followed by reduction of the 1,1-dihalo-4-methyl-1-penten-3-one produced thereby, and dehydration of the resulting 1,1-dihalo-3-hydroxy-4-methyl-1-pentene.
1,1-二卤代-4-甲基-1,3-戊二烯是合成杀虫剂二卤乙烯基环丙酸酯的关键中间体,可通过三步反应制备。首先,在路易斯酸催化下,将乙烯基卤化物和异丁酰卤化物进行弗里德尔-克拉夫茨缩合反应,然后还原所产生的1,1-二卤代-4-甲基-1-戊烯-3-酮,最后脱水得到1,1-二卤代-3-羟基-4-甲基-1-戊烯。