Synthesis
The general procedure for the synthesis of 2,3-difluoro-6-nitroaniline from 2,3,4-trifluoronitrobenzene was as follows: 8.85 g (50 mmol) of 2,3,4-trifluoronitrobenzene was dissolved in 50 ml of ethanol. To this solution was added 13.62 g (200 mmol equivalent) of 25% ammonia followed by stirring the reaction mixture for 8 hours at room temperature. After completion of the reaction, ethanol was removed by distillation and then the reaction mixture was filtered. The crude product obtained was washed with water and subsequently dried under reduced pressure to afford 7.94 g (45.6 mmol, 91.2% yield) of 2,3-difluoro-6-nitroaniline. The structure of the resulting compound was confirmed by 1H-NMR analysis.
References
[1] Patent: JP2015/227293, 2015, A. Location in patent: Paragraph 0033; 0034
[2] Patent: WO2010/20363, 2010, A1. Location in patent: Page/Page column 96-97, 119-120
[3] Patent: US2013/287686, 2013, A1. Location in patent: Paragraph 0135; 0136
