反应详情

Sodium nitrate (1.7 g) was added to a concentrated sulfuric acid (7 ml) solution containing 2,3-difluorobenzoic acid (1.58 g), followed by stirring at room temperature for 0.5 hours. The reaction solution was poured into ice water, followed by extraction with ethyl acetate. The organic layers were dried over anhydrous sodium sulfate. The solvent was distilled away under reduced pressure, the obtained residue was purified by silica gel chromatography (n-hexane:ethyl acetate=1:0 to 4:1). A light yellow solid of 2,3-difluoro-5-nitrobenzoic acid (1.61 g) was thus obtained.

1. extractionfollowed by extraction with ethyl acetate
2. dry with materialThe organic layers were dried over anhydrous sodium sulfate
3. distillationThe solvent was distilled away under reduced pressure
4. customthe obtained residue was purified by silica gel chromatography (n-hexane:ethyl acetate=1:0 to 4:1)