反应详情

温度

40 °C

Methyl 3-amino-2-fluorobenzoate hydrochloride (18.65 g, 0.09 mol) was dissolved in a 37% formalin solution. While maintaining the temperature at 40° C. or lower, 98% sulfuric acid (680.81 g, 6.80 mol) was added dropwise thereto. Thereafter, the mixture was naturally cooled, and agitated for 2 hours at room temperature. The reaction mixture was poured into ice water, and was neutralized with sodium bicarbonate. The neutralized liquid was filtered, and washed with ethyl acetate. Then, the filtrate was extracted, and dried over anhydrous sodium sulfate. The sodium sulfate was filtered away, and then the concentration residue was purified by silica gel column chromatography (developer solvent: ethyl acetate/n-hexane=1/4), as a result of which 6.27 g (yield: 38%) of the indicated compound was obtained.

1. temperatureThereafter, the mixture was naturally cooled
2. filtrationThe neutralized liquid was filtered
3. washwashed with ethyl acetate
4. extractionThen, the filtrate was extracted
5. dry with materialdried over anhydrous sodium sulfate
6. filtrationThe sodium sulfate was filtered away
7. customthe concentration residue was purified by silica gel column chromatography (developer solvent: ethyl acetate/n-hexane=1/4)