反应详情

2 g (11.48 mmol) of 2,8-dimethyl-4H-chromen-4-one are dissolved in 15 ml of concentrated sulfuric acid and, at 0° C., 0.7 g (11.48 mmol) of fuming nitric acid is added, during which the temperature should not exceed 5° C. The mixture is then stirred at room temperature for 1 h. The reaction mixture is poured into ice-water, whereupon a colorless solid precipitates. This is filtered off and washed several times with water and ice-cold methanol. 2.3 g (90.8% of theory) of the title compound are obtained.

1. customexceed 5° C
2. customprecipitates
3. filtrationThis is filtered off
4. washwashed several times with water and ice-cold methanol