2-氟环丙烷甲酸的合成

Synthesis of 2-Fluorocyclopropane Carboxylic Acid

以烯丙醇为原料,经苄基保护、环化、脱苄基、脱溴、氧化后制得2-氟环丙烷甲酸,总产率为35.3%。采用1HNMR、MS法对中间产物和目标产物进行结构表征。并通过考察各步的反应条件,得出最佳的工艺条件为:环化反应中n(烯丙基苄基醚)∶n(二溴氟甲烷)=1∶1.2,以苄基三乙基氯化铵为相转移催化剂;采用锌粉为还原剂,温度为70℃;氧化反应中最佳溶剂为体积比4∶1的丙酮-水混合溶剂。

In this study, the target product 2-fluorocyclopropane carboxylic acid has been prepared from allyl alcohol in five steps. First, allyl alcohol was protected by benzyl group, then after cyclization benzyl group was removed,which was followed by debromination and oxidation. The title compound has been synthesized with an overall yield of 35.3 %. The characterization methods of 1HNMR and MS were applied to confirm the structures of the intermediates and the final product. By investigating the reaction conditions of each step, the optimal conditions were determined as follows：In the cyclization reaction, n （ allylbenzyl ether） ： n （dibromofluoromethane） = 1 ： 1.2 and benzyl triethylammonium chloride was used as phase transfer catalyst; zinc powder was used as reducing agent at 70 ℃;the best solvent for oxidation was a mixed solvent of acetone and water（ volume ratio 4：1 ）.