A process for the preparation of a di-(halo)-vinyl compound, useful as an intermediate in the manufacture of pyrethroid insecticides, of the general formula:
wherein Hal represents a halogen atom and R' an alkyl group or a substituted cyclopropyl group of the general formula:
wherein R2 represents a substituted or unsubstituted alkyl group, wherein (a) a tri(dialkylamino)phosphine or an alkyl ester of an ortho-phosphorous acid bis(dialkylamide) is reacted with a tetrahalomethane or a trihalomethane and (b) the product resulting from the first step is reacted with an aldehyde of the general formula:
wherein R' has the same meaning as in the general formula I, both steps being carried out in the presence of a substantially inert solvent.
一种制备二(卤代)
乙烯基化合物的工艺,该化合物可作为生产拟
除虫菊酯类杀虫剂的中间体,其通式为: 其中 Hal 代表卤原子,R' 代表烷基或取代的环丙基,其通式为: 其中 R2 代表取代或未取代的烷基,其中 (a) 三(二烷基
氨基)膦或正
磷酸双(二烷基酰胺)的烷基酯与四卤
甲烷或三卤
甲烷反应,(b) 第一步得到的产物与通式为: 其中 R' 的醛反应,其含义与通式 I 中的含义相同,这两个步骤均在基本惰性的溶剂存在下进行。