Chemical Properties
white to light yellow crystal powder
Uses
2,4-Dichloro-5-fluoro-3-nitrobenzoic acid may be used to synthesize:
- ethyl 3-(N,N-dimethylamino)-2-(2,4-dichloro-5-fluoro-3-nitrobenzoyl)acrylate
- 7-chloro-1-cyclopropyl-6-fluoro-8-nitro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid
- ethyl-3-(N,N-dimethylamino)-2-(2,4-dichloro-5-fluoro-3-nitrobenzoyl) acrylate
- substituted 4(1H)-oxoquinoline-3-carboxylic acid
General Description
2,4-Dichloro-5-fluoro-3-nitrobenzoic acid can be prepared from 2,4-dichloro-5-fluorobenzoic acid.
Synthesis
General procedure for the synthesis of 2,4-dichloro-5-fluoro-3-nitrobenzoic acid from 2',4'-dichloro-5'-fluoroacetophenone: 55 g (0.55 mol) of concentrated sulfuric acid was added to a 250 mL three-necked flask with a stirrer and reflux condenser tube. Under stirring (stirring speed of 400 r/min), 19.29 g (0.3 mol) fuming nitric acid was slowly added to the three-necked flask. Subsequently, the reaction mixture was warmed up to 103 °C and 10.46 g (0.05 mol) of pre-melted 2,4-dichloro-5-fluoroacetophenone was slowly added dropwise at this temperature, controlling the dropwise temperature to be between 103 and 110 °C. After the dropwise addition was completed, the reaction temperature was maintained at 106 °C to continue the reaction for 3 hours. After completion of the reaction, the mixture was cooled to 10 °C and separated by filtration. The filtrate was recovered and set aside, and the filter cake was washed with water. Finally, the filter cake was recrystallized with toluene to give 11.67 g of 2,4-dichloro-5-fluoro-3-nitrobenzoic acid with 99% purity and 91% yield.
References
[1] Patent: CN103922942, 2016, B. Location in patent: Paragraph 0026; 0027
[2] Journal of Heterocyclic Chemistry, 1988, vol. 25, p. 927 - 930
