一步法合成甘氨酸叔丁酯及其盐酸盐

One-step Synthesis of tert-Butyl Glycinate and Its Hydrochloride Salt

甘氨酸叔丁酯一般经由先合成氨基被保护的甘氨酸叔丁酯,再加氢脱去保护基而间接生成。采用溴乙酸叔丁酯与过量的液氨(1mol溴乙酸叔丁酯 600mL液氨)在-33～-35℃反应,成功地直接合成了甘氨酸叔丁酯。在甘氨酸叔丁酯的乙醚溶液中通入干燥的HCl气体,控制pH值大于6 5,且反复沉淀、过滤的操作方式,制得了甘氨酸叔丁酯盐酸盐。产物分子结构用元素分析、红外光谱及核磁共振谱(1HNMR)进行了鉴定。此法总得率86 3%,目标物的质量分数≥98%。

Generally,glycine tertbutyl ester is obtained indirectly through hydrogenation of Nprotected glycine tertbutyl esters.In this paper it is synthesized directly by reaction of tertbutyl bromoacetate with a large excess of liquid ammonia (1 mol tertbutyl bromoacetate/600 mL liquid ammonia) at -33 - -35 ℃.tertButyl glycinate hydrochloride is produced by treating the anhydrous ether solution of tertbutyl glycinate with dry gaseous hydrogen chloride in a way that pH values are controlled larger than 6.5.The precipitate is filtered off and the filtrate is treated repeatedly in the same way until precipitation is complete.The molecular structure of tertbutyl glycinate hydrochloride is characterized and confirmed by elementary analysis,FTIR and 1HNMR.Yield of the HCl salt (based on tertbutyl bromoacetate) is as high as 86.3% and the purity is ≥98%.