| 专利名称 | Process for the preparation of 3,3',4,4'-biphenyltetracarboxylic acid and its derivatives | 申请号 | US19890418059 | 专利类型 | US | 公开（公告）号 | US5081281 | 公开（授权）日 | 1992.01.14 | 申请（专利权）人 | 中国科学院长春应用化学研究所 | 发明（设计）人 | DING MENGXIAN (CN); YANG ZHENGHUA (CN); WANG ZUGIANG (CN); ZHANG JING (CN) | 主分类号 | C07C67/343 | IPC主分类号 | C07C67/343 | 专利有效期 | Process for the preparation of 3,3',4,4'-biphenyltetracarboxylic acid and its derivatives 至Process for the preparation of 3,3',4,4'-biphenyltetracarboxylic acid and its derivatives | 法律状态 | 说明书摘要 | Biphenyl tetracarboxlic acid esters and derivatives thereof are prepared by the coupling reaction of 4-halogen substituted o-benzenedicarboxylic acid ester, carried out in an aprotic polar solvent in the presence of a pre-prepared triphenylphosphine-nickel chloride or trialkylphosphine-nickel chloride catalyst, zinc powder as the reducing agent, and an alkali metal halide promoting agent. The ester may be hydrolyzed in basic solution to afford the corresponding acid. The acid may be heated or boiled with acetic anhydride to afford the biphenyl dianhydride. |
1、源头对接，价格透明
2、平台验证，实名审核
3、合同监控，代办手续
4、专员跟进，交易保障