One-stage procedure of synthesis of highly reactive α-chloro-β-ketoacetals. 4-chloropyrazoles from α-chloro-β-ketodimethoxyacetals
作者:G. V. Bozhenkov、V. A. Savosik、A. N. Mirskova、G. G. Levkovskaya
DOI:10.1134/s1070428008020024
日期:2008.2
Conditions were developed where the reaction of alkyl 1,2-dichlorovinyl ketones with alcohols and 1,2-dihydroxybenzenes led to the formation of the corresponding open-chain and cyclic α-chloro-β-ketoacetals. The reaction of α-chloro-β-alkylketodimethoxyacetals with alkyl-, benzyl-, and arylhydrazines resulted in 1,3-substituted 4-chloropyrazoles in 70–90% yields demonstrating that primarily formed 2,2-dimethoxy-1-chloroethyl alkyl ketones hydrazones underwent heterocyclization.
开发了一些条件,使得烷基1,2-二氯乙烯酮与醇和1,2-二羟基苯的反应生成相应的开放链和环状α-氯-β-酮乙缩醛。α-氯-β-烷基酮二甲氧基乙缩醛与烷基、苄基和芳基肼的反应生成了1,3-取代的4-氯吡唑,产率为70-90%,表明主要生成的2,2-二甲氧基-1-氯乙基烷基酮肼类化合物发生了杂环化反应。