环丙基甲酸的合成工艺研究

Synthesis of Cyclopropylcarboxylic Acid

标题化合物是一种重要的化学中间体。在氯化锌的作用下,1,4-丁内酯与异丙醇、SOCl2反应经一步开环-酯化反应生成4-氯丁酸异丙酯。在Na OH作用下,4-氯丁酸异丙酯合环缩合生成环丙基甲酸异丙酯,优化环丙基甲酸异丙酯水解酸化生成环丙基甲酸的工艺。在环丙基甲酸异丙酯水解之后,先蒸出异丙醇再酸化,可以防止蒸馏过程中环丙基甲酸与异丙醇再次酯化生成环丙基甲酸异丙酯。将文献中的萃取剂乙酸乙酯换为二氯甲烷,优点是除去了后处理过程中的副产物环丙基甲酸乙酯和乙酸异丙酯。经优化后不仅减少了副反应而且提高了产率,总收率为75.1%。目标产物及中间体经1HNMR和IR表征并确认结构。

Cyclopropylcarboxylic acid is an important chemical intermediate. Under the action of thionyl chloride,1,4-butyrolactone and isopropanol,SOCl2 reaction by one-step ring-esterification to produce 4-chlorobutyric acid isopropyl ester.Under the action of Na OH,4-chlorobutyric acid isopropyl ester ring condensation to produce cyclopropanecarboxylic acid isopropyl ester. Optimization of hydrolysis and acidification of isopropyl formate with cyclopropane to produce formic acid. The first distillation of isopropyl alcohol can be removed during the post-treatment cyclopropyl formic acid and isopropyl alcohol esterification again to produce propyl cyclopropylchloroformate.The isopropyl alcohol is distilled off and then the acid extract of the extractant in the original document is changed to methylene chloride.The advantage is that the by-product cyclopropanecarboxylic acid ethyl ester and isopropyl acetate are removed during the post-treatment.The optimization has not only reduced the side effects but also increased the yield.The overall yield was 75. 1%.The target product and intermediates were confirmed by1 HNMR and IR.