Abstract: The laboratory preparation of 3,3′,4,4′-biphenyltetracarboxylic anhydride, which is an important monomer of polyimide, was investigated.The improvement of the synthesis method was on the halogenating reaction of o-phthalic anhydride and the dehalogenation-dimerization of monosodium 4-bromo-o-phthalate.The circulation of the catalyst was discussed.The optimal reaction conditions (solvent,temperature, time, yield)were as follows, brominating: water, 75 ℃,4 h, 78%; dehalogenation-dimerization: water, 100 ℃, 3 h, 90.4%; cyclization: acetic anhydride, reflux, 2 h, 97%.High purity product was obtained with overall yield of 68.4%.

摘要： 3,3′,4,4′-联苯四甲酸二酐是合成全芳香族聚酰亚胺的重要单体.对其合成路线进行了优化：以邻苯二甲酸酐为原料，经溴化、催化脱卤偶联、脱水环化得到高纯度的3,3′,4,4′-联苯四甲酸二酐.同时通过对Pd/C的循环利用进行了研究，确定了Pd/C的合理使用方案.各步反应的最佳条件（反应试剂、反应温度、反应时间、摩尔收率）分别为，溴化：水，75 ℃，4 h，78％; 脱卤偶联：水，100 ℃， 2 h，90.4％;脱水环化：乙酸酐，回流， 2 h，97％.优化后路线操作简单，各步反应副反应少，收率较高，总收率达68.4％，产品纯度高，金属离子含量符合要求.