α-溴代异丁酸叔丁酯合成方法的改进

Improvement on the Synthetic Method of tert-Butyl α-Bromoisobutyrate

以异丁酸、二氯亚砜、叔丁醇和单质溴为原料,经过酰化、酯化、溴代3步反应合成了α-溴代异丁酸叔丁酯,以元素分析、IR、HNMR确认了目标化合物的结构。重点研究了影响酯化反应的因素,确定了酯化反应的最佳条件:三聚磷酸钠为吸收剂,氯仿为溶剂,异丁酰氯与叔丁醇的物质的量比1∶1.3、反应时间2 .5h、收率85 .1%。

Tert-butyl α-bromoisobutyrate was prepared from iso-butanoic acid,thionyl chloride,tert-butanol and bromine through acylation,esterification and bromization.The structure of the title compound was affirmed by EA,IR and NMR.The primary factors of the esterification were studied and the optimum reaction conditions were determined as follows:sodium triphosphate as absorbent,chloroform as solvent,molar ratio of iso-butanoyl chloride to tert-butanol equacto 1.0∶1.3,reaction time 2.5h,and the yield is 85.1%.