反应详情

16.9 g (0.11 mol) of 3,4-dihydroxybenzoic acid in 170 ml of tetrahydrofuran are treated with 5 g (0.1 mol) of hydrazine hydrate and 1.1 g (0.01 mol) of 1-hydroxy-2-(1H)-pyridone. A solution of 22.7 g (0.11 mol) of dicyclohexylcarbodiimide in 200 ml of tetrahydrofuran is added to the reaction mixture at 20° within 15 minutes. The reaction mixture is stirred at 20° for 16 hours. The resulting dicyclohexylurea is filtered off and the filtrate is evaporated. The residue is stirred with 60 ml of ethanol at 20° for 2 hours and the crystalline crude product is subsequently filtered off under suction and dried firstly in a water-jet vacuum and then in a high vacuum at 40°, whereby 3,4-dihydroxybenzoic acid hydrazide is obtained as a beige powder.

1. filtrationThe resulting dicyclohexylurea is filtered off
2. customthe filtrate is evaporated
3. stirringThe residue is stirred with 60 ml of ethanol at 20° for 2 hours
4. filtrationthe crystalline crude product is subsequently filtered off under suction
5. dry with materialdried firstly in a water-jet vacuum