反应详情

温度

10 °C

A mixture of 2-amino-N,3-dimethylbenzamide (i.e. the product of Step A) (16.6 g, 100 mmol) and N,N-dimethylformamide (15.0 g) was cooled to 10° C. and concentrated hydrochloric acid (70 g, 700 mmol) was slowly added. Then the mixture was heated to 30° C., and 30% aqueous hydrogen peroxide (18.5 g, 160 mmol) was added dropwise over 15 minutes at 30-35° C. After stirring at about 35° C. for 3 h, the mixture was cooled to about 10° C., and then water (200 mL) was added. Sodium sulfite (7.56 g, 60 mmol) was added, and then the pH was adjusted to 2.2 by slow addition of 50% aqueous sodium hydroxide (38.1 g). After stirring at 10° C. for 15 minutes, the mixture was filtered, and the solids were washed with water (2×50 mL), and dried in the vacuum oven to afford the title compound as pink solids, 14.61 g (72.7% yield). Quantitative HPLC of the solid product showed 99.1 wt % of the title compound.

1. temperatureThen the mixture was heated to 30° C.
2. temperaturethe mixture was cooled to about 10° C.
3. stirringAfter stirring at 10° C. for 15 minutes
4. filtrationthe mixture was filtered
5. washthe solids were washed with water (2×50 mL)
6. customdried in the vacuum oven