巯基乙酸的合成

Synthesis of Thioglycollic Acid

本实验以氯乙酸和多硫化钠为原料经中和、巯基化、还原等三步反应合成了巯基乙酸。考察了物料配比、反应温度、酸化还原的时间及酸化还原时采用不同的酸四因素对合成巯基乙酸收率的影响 ,确定了最优化的反应条件。最优化的反应条件为 :n(氯乙酸 )∶n(多硫化钠 ) =2∶1,于 70℃～ 75℃反应 1h ,酸化还原的时间为 :40min ,酸化还原时采用硫酸 (与水体积比为 1∶1) ,并获得了较好的收率。对产品进行了相关理化指标、红外光谱分析 。

Thioglycollic acid is synthesized with chloroacetic acid and sodium polysulfide as raw materials by neutralization, sulfhydrylition and reduction.In the course of the experiment we study conditions of four factors, for example material proportion, reduction reaction temperature, reaction time and sorts of acid. The optimum technological conditions were obtained the molar ratio of n(ClCH 2 COOH):n(Na 2 S 2 )= 1:2; reaction temperature was 70～75℃, reduction reaction time was 40 min with H 2 SO 4 .Excellent yield was 89.7%.We found the best condition and got the optimum yield.The process is very simple. Related specifieation and IR character of the products were determined.