氯铝酸咪唑离子液体催化法合成4,4′-二氟二苯甲酮

Synthesis of 4,4'-Difluorobenzophenone Catalyzed by Acidic Imidazolium Chloroaluminate Ionic Liquid

4，4’-二氟二苯甲酮（1）是重要的医药和化工中间体，可用于合成强效脑血管扩张药氟桂利嗪（flunarizine）及中枢兴奋药阿米三嗪（almitrine）等，可由氟苯与光气直接酰化缩合制得，收率66％，但含有25％的副产物2，4’-二氟二苯甲酮。。文献用4，4’-二氨基二苯甲烷为原料，在氟硼酸作用下经重氮化、分解、氧化等反应制得1，纯度〉99％，但步骤较多，总收率约54％。

4,4＇-Difluorobenzophenone was prepared from fluorobenzene with diphosgene in acidic imidazolium chloroaluminate ionic liquid （[Bmim] C1-AIC13）. The mole ratio of [Bmim] Cl-AlCl3-fluorobenzene-diphosgene is 1.9 ： 3.6 ： 1. In the presence of a small amount of activated carbon, the reaction was carried out for 4 h at 70 ℃ with a yield of 85%.