反应详情

A total of 7.2 g of 3,4-dihydroxy-5-nitrobenzonitrile are introduced portionwise into 130 ml of conc. sulfuric acid while stirring within 10 minutes, whereupon the mixture is stirred at 50° for 4 hours. The reaction mixture is poured into 800 ml of ice-water. The separated precipitate is filtered under suction, washed with water and taken up in ethyl acetate. The organic phase is dried over sodium sulfate and evaporated. After recrystallization from acetone/ethyl acetate there is obtained 3,4-dihydroxy-5-nitrobenzamide in the form of orange crystals of m.p. 235°-236°.

1. stirringis stirred at 50° for 4 hours
2. filtrationThe separated precipitate is filtered under suction
3. washwashed with water
4. dry with materialThe organic phase is dried over sodium sulfate
5. customevaporated
6. customAfter recrystallization from acetone/ethyl acetate there