反应详情

Potassium nitrate (0.625 g) was added with stirring to a solution of the compound prepared in Example 278 (0.500 g) in sulfuric acid (2.47 mL) at 0° C. The mixture was allowed to warm up to room temperature and then heated slowly to 75° C. After heating for 2 hours, the mixture was cooled to room temperature, poured into ice, pH adjusted to 4 with 10% aqueous sodium hydroxide, and the precipitated to obtain the title compound (0.440 g) having the following physical data.

1. temperatureheated slowly to 75° C
2. temperatureAfter heating for 2 hours
3. temperaturethe mixture was cooled to room temperature
4. additionpoured into ice
5. customthe precipitated