包结法分离联苯甲酸同分异构体

Research on separation of biphenylcarboxylic acid isomers by inclusion isolation method

以β-环糊精(-βCD)为主体,利用包结分离法实现3-联苯甲酸和4-联苯甲酸同分异构体的分离。分别考察了加热温度、搅拌时间、包结时间、物料配比对分离结果的影响,最终确定搅拌时间为2.5 h,加热温度控制在60—70℃。通过设计正交试验,确定了影响4-联苯甲酸收率和选择性的主要因素为β-CD与联苯甲酸原料的物料配比,并且选择了最佳分离条件:当加热温度为60℃,搅拌时间为2.5 h,包结时间为2 d,-βCD与联苯甲酸原料的摩尔比为1∶2时,分离效果最佳,4-联苯甲酸的收率可达35.47%,而纯度(质量分数)可达99%以上。

The inclusion isolation method was used to separate the isomers of 4-biphenylcarboxylic acid and 3-biphenylcarboxylic acid by taking β-cyclodextrin（β-CD） as host.The influence of heating temperature,stirring time,inclusion time and material ratio on the separation results was studied respectively.The stirring time is defined at 2.5 h and the heating temperature is controlled at 60-70 ℃.Orthogonal test shows that molar ratio of β-CD to biphenylcarboxylic acid is the most important factor to influence the yield and selectivity of 4-biphenylcarboxylic acid.The best separation conditions are as follows： molar ratio of β-cyclodextrin to biphenylcarboxylic acid is 1∶2,heating temperature is 60 ℃,stirring time is 2.5 h,and inclusion time is 2 d.Under these conditions,the separation result is the best.The yield of 4-biphenylcarboxylic acid can reach 35.47%,and the purity can reach more than 99%.