反应详情

温度

-10 °C

(2,3-Difluoro-phenyl)-acetic acid (11, 5 g, 0.0290 mol) is dissolved in concentrated sulfuric acid (20 ml) and the resulting solution cooled to −10° C. with vigorous stirring. A solution of nitric acid (1.88 ml, 69.3%, 0.0290 mol) and sulfuric acid (2 ml) is added dropwise at a rate such that the temperature remains below −5° C. The thickened slurry is stirred for 15 minutes and then poured on ice. The resulting white precipitate is filtered and dried under vacuum (6.3 g, 99%) and consists of a 50/50 mixture of 5 and 6-NO2 regioisomers suitable for use directly in the next step.

1. customremains below −5° C
2. additionpoured on ice
3. filtrationThe resulting white precipitate is filtered
4. customdried under vacuum (6.3 g, 99%)
5. additionconsists of a 50/50 mixture of 5 and 6-NO2 regioisomers suitable for use directly in the next step