反应详情

4 g (20 mmol) of the product obtained in Stage A are dissolved in 16 ml of concentrated sulfuric acid with stirring and cooling in ice. The solution is brought to 55° C. and 1.3 ml of concentrated nitric acid are added dropwise, care being taken to maintain the temperature between 55° and 60° C. The stirring is continued for 20 minutes and the mixture is then poured onto crushed ice. The product is precipitated by addition of 40% sodium hydroxide. It is filtered off, washed with water and then dried. 3.7 g of product are thus collected. The product is recrystallized from 95° C. ethanol.

1. temperaturecooling in ice
2. customis brought to 55° C.
3. temperatureto maintain the temperature between 55° and 60° C
4. additionthe mixture is then poured
5. customonto crushed ice
6. customThe product is precipitated by addition of 40% sodium hydroxide
7. filtrationIt is filtered off
8. washwashed with water
9. customdried
10. custom3.7 g of product are thus collected
11. customThe product is recrystallized from 95° C. ethanol