环丙胺合成的新方法

采用γ 丁内酯和异丙醇为起始原料 ,经 5步反应合成环丙胺 :γ 丁内酯开环酯化得γ 氯代丁酸异丙酯 (Ⅰ ) ,产率 93% ;通过固 /液相转移催化 (PTC) ,由Ⅰ合成了环丙烷甲酸异丙酯 (Ⅱ ) ,产率 92 % ;Ⅱ经液 /液PTC水解、中和制得环丙烷甲酸 (Ⅲ ) ,产率 85 % ;Ⅲ和尿素发生酰化反应 ,生成环丙甲酰胺 (Ⅳ ) ,产率 82 9% ;最后Ⅳ经Hofmann降解 ,得目的产物环丙胺 (Ⅴ ) ,产率87 2 % ,总收率达 5 2 6 %。在环化和水解这关键的两步采用了相转移催化 ,使得整个路线反应条件温和 ,时间短 ,原材料价廉易得 ,可望适合工业规模生产。

A New Approach to Synthesis of Cyclopropylamine

A new approach to synthesize cyclopropylamine was described from γ butyrolactone and isopropanol by the following five step reactions.Isopropyl γ chlorobutyrate(Ⅰ) was prepared by the reaction of γ butyrolactone with isopropanol and thionyl chloride and was cyclized to produce isopropyl cyclopropanecarboxylate(Ⅱ) by solid/liquid phase transfer catalysis (PTC).Compound Ⅱ was hydrolyzed by liquid/liquid PTC and the hydrolysate was further neutralized with acid to give cyclopropanecarboxylic acid(Ⅲ).Then cyclopropylamide(Ⅳ) was prepared by the reaction of compound Ⅲ with urea,and finally,cyclopropylamine was synthesized by Hofmann degradation of compound Ⅳ.Phase transfer catalysis was used in the two key steps of cyclization and hydrolysis,and effects of types and amount of PTC,reaction temperature and molar ratio of reactants on the yield were discussed.Results of experiments show that this new route is superior to the former ones and feasible for production with simple processes,mild reaction conditions and cheap materials.The total yield of cyclopropylamine was summed up to 52 6%.