Uses
2-Chloro-4,5-difluorobenzoic acid (CDFBA) is an important pharmaceutical and pesticide intermediate, mainly used in the production of novel antibacterial drugs such as fluopyridine and cardiovascular drugs.
Chemical Properties
white to light yellow crystal powder
Uses
2-Chloro-4,5-difluorobenzoic acid is an important intermediate in medicinal compounds and pesticides.
Lanthanide complexes with the 2-chloro-4,5-difluorobenzoate (2-cl-4,5-dfba) and 1,10-phenanthroline (phen), have been prepared and their crystal structures have been studied.
Efficient synthesis of 2-chloro-4,5-difluorobenzoic acid v-difluororbenzene has been reported.
General Description
2-Chloro-4,5-difluorobenzoic acid is an important intermediate in medicinal compounds and pesticides. Lanthanide complexes with the 2-chloro-4,5-difluorobenzoate (2-cl-4,5-dfba) and 1,10-phenanthroline (phen), have been prepared and their crystal structures have been studied. Efficient synthesis of 2-chloro-4,5-difluorobenzoic acid v-difluororbenzene has been reported.
Synthesis
Example 2 Preparation of 2-chloro-4,5-difluorobenzoic acid: 280.4 g (0.4 mol) of 12% sodium hypochlorite aqueous solution was added to 19.1 g (0.1 mol) of 1-(2-chloro-4,5-difluorophenyl)ethanone. The reaction mixture was stirred under reflux conditions for 4 hours. After completion of the reaction, the reaction was cooled to room temperature and the pH was adjusted slowly and dropwise with concentrated hydrochloric acid to 1. The precipitated white crystals were dissolved with dichloromethane and the organic and aqueous phases were separated. The aqueous phase was extracted twice with dichloromethane and the organic phases were combined. The solvent was removed by distillation to give 16.4 g (yield: 85.1%) of 2-chloro-4,5-difluorobenzoic acid as white crystals.
References
[1] Organic Preparations and Procedures International, 1991, vol. 23, # 5, p. 655 - 658
[2] Patent: US4994610, 1991, A
[3] Patent: US5093515, 1992, A
[4] Organic Preparations and Procedures International, 1996, vol. 28, # 2, p. 245 - 246
[5] Patent: EP342849, 1990, A3
