申请人:Gulf Research and Development Company
公开号:US04173573A1
公开(公告)日:1979-11-06
A process for preparing 3,4,3',4'-benzophenonetetracarboxylic dianhydride which comprises condensing an impure ortho-xylene mixture with acetaldehyde in contact with an acid catalyst to obtain an impure 1,1-bis(3,4-dimethylphenyl)ethane mixture, oxidizing the 1,1-bis(3,4-dimethylphenyl)ethane mixture with nitric acid to obtain a mixture of carboxylic acids, from which by crystallization and dehydration substantially pure 3,4,3',4'-benzophenonetetracarboxylic dianhydride is recovered.
一种制备3,4,3',4'-苯并苯酮四羧酸酐的过程,包括将不纯的邻二甲苯混合物与乙醛在酸催化剂的作用下缩合,得到不纯的1,1-双(3,4-二甲基苯基)乙烷混合物,将该混合物用硝酸氧化得到一种羧酸混合物,通过结晶和脱水得到基本纯净的3,4,3',4'-苯并苯酮四羧酸酐。