反应详情

To a mixture of 5-fluoro-2-hydroxybenzoic acid (3.08 g, 19.76 mmol) in concentrated H2SO4 (30 mL) below 0° C. was added dropwise a mixture of concentrated HNO3 (2.11 g, 21.74 mmol) and concentrated H2SO4 (6 mL) with stirring below 5° C. After the addition, the mixture was stirred at this temperature for 2 hr. The reaction mixture was poured onto crash ice and the precipitate was collected, then the precipitate was dissolved in ethyl acetate (100 mL), washed with water (50 mL×2), brine (30 mL), dried over anhydrous sodium sulfate and concentrated to give 5-fluoro-2-hydroxy-3-nitrobenzoic acid (3.8 g) as a brown solid. LC-MS (ESI) m/z 202 [M+1]+.

1. additionwas added dropwise
2. additionAfter the addition
3. stirringthe mixture was stirred at this temperature for 2 hr
4. additionThe reaction mixture was poured onto crash ice
5. customthe precipitate was collected
6. dissolutionthe precipitate was dissolved in ethyl acetate (100 mL)
7. washwashed with water (50 mL×2), brine (30 mL)
8. dry with materialdried over anhydrous sodium sulfate
9. concentrationconcentrated