ZnCl_2-KBH_4还原苯酐合成邻苯二甲醇的研究

Study on Synthesis of 1,2-Benzenedimethanol by Reduction from Phthalic Anhydride with Using ZnCl_2-KBH_4

邻苯二甲醇是一个重要的邻-亚二甲苯基保护剂,也是合成邻苯二甲醛的重要原料。以四氢呋喃为溶剂,使用氯化锌提高硼氢化钾的还原性,通过ZnCl2-KBH4还原苯酐来制取邻苯二甲醇,反应条件温和,收率高,对环境友好。通过对反应物料比例、温度、时间的考察,确定了优化的反应条件为:物料物质的量比为KBH4:ZnCl2:苯酐=3:1.5:1,反应温度为60℃,反应时间为10h时,此时收率大于91%。

1,2-Benzenedimethanol is an important protective agent for o-xylylene,and also a key material for synthesizing o-phthalaldehyde.The ZnCl2 is used to improve the reducibility of KBH4,the reaction conditions for preparing 1,2-benzenedimethanol are mild and friendly to environment which adopted ZnCl2-KBH4 to reduce phthalic anhydride in THF,and the reaction yield is high.The optimal reaction conditions are confirmed by means of investigating raw materials ratio,reaction temperature and time.The optimum reaction conditions are listed as follows： the raw materials molar ratio is KBH4∶ZnCl2∶phthalic anhydride=3∶1.5∶1,the reaction temperature and time is 60℃ and 10h respectively.Under these conditions,the yield is higher than 91%.