dl-酒石酸的合成工艺研究

Study on the synthetic process of dl-tartaric acid

改进了外消旋酒石酸(dl-酒石酸)的合成工艺:以顺丁烯二酸酐为原料,经环氧化反应合成相应的环氧丁二酸(氢)钙中间体,然后经酸化、抽滤除去钙离子,滤液通过水解反应获得目标产物dl-酒石酸。最后调节母液pH值获得产物酒石酸氢钾。同时考察了反应温度、反应时间、催化剂用量、氧化剂用量等对收率的影响,得到适宜的反应条件:制备环氧丁二酸钙,摩尔比n(顺丁烯二酸酐):n(碳酸钙):n(过氧化氢):n(催化剂)=1:0.98:1.50:0.006,50℃反应4 h,收率为92.5%;制备环氧丁二酸氢钙,n(顺丁烯二酸酐):n(碳酸钙)=1:0.54,70℃反应4 h,收率为95.0%;制备dl-酒石酸,n(Ca2+):n(H2SO4)=1:1.50,室温下酸化4 h,收率为82.2%。中间体母液套用3次,收率仍然稳定;dl-酒石酸母液套用3次,每次收率均大于95%。中间体和产品结构经熔点仪、傅里叶红外光谱仪(FTIR)表征,均与标准样品一致。

An improved process was designed for the synthesis of racemic tartaric acid(dl-tartaric acid).Calcium epoxysuccinate and calcium hydrogen epoxysuccinate intermediates were synthesized via epoxidation reaction using maleic anhydride as a raw material.Calcium ions were then removed by acidification and filtration,and dl-tartaric acid was prepared via hydrolysis reaction.Finally,the pH value of mother liquor was adjusted to obtain potassium hydrogen tartrate.The effects of experimental parameters,such as reaction temperature,reaction time,catalyst dosage and oxidant dosage were investigated.The optimum synthetic conditions of calcium epoxysuccinate is the molar ratio of n(maleic anhydride):n(calcium carbonate):n(hydrogen peroxide):n(catalyst)=1:0.98:1.50:0.006 at 50℃for 4 h℃with a yield of 92.5%.For calcium hydrogen epoxysuccinate,this condition is n(maleic anhydride):n(calcium carbonate)=1:0.54 at 70℃for 4 h with a yield of 95.0%,and for dl-tartaric acid,n(Ca2+):n(H2SO4)=1:1.50 at 25 for 4 h with a yield of 82.2%.The yield remains stable when intermediates mother liquors are recycled for three times.The yield of dl-tartaric acid is over 95%each time when reused for 3 times.The structures of intermediates and products were identified by melting points and Fourier infrared spectrum(FTIR),which are consistent with standard samples.