Citric Acid → 2-Amino-3-nitrobenzoic acid

Reaction equation

[N+:1]([C:4]1[CH:5]=[CH:6][CH:7]=[C:8]2[C:12]=1[NH:11]C(=O)[C:9]2=[O:14])([O-:3])=[O:2].OO.C(O)(=O)CC(CC(O)=O)(C(O)=O)[OH:20]>[OH-].[Na+]>[NH2:11][C:12]1[C:4]([N+:1]([O-:3])=[O:2])=[CH:5][CH:6]=[CH:7][C:8]=1[C:9]([OH:14])=[O:20]

Participants

Procedure

To a ice cold solution of 7-nitro-1H-indole-2,3-dione (9 g, 47 mmol) in 2 M aqueous sodium hydroxide (50 mL), an aq. solution of 30% hydrogen peroxide (9 mL) was added drop wise. The mixture was warmed to room temperature and stirred overnight. The resulting mixture was carefully acidified by the addition of an aq. saturated citric acid solution. The solid precipitate was collected by filtration, washed with water and dried in a vacuum oven to get 6 g of the required product as a yellow coloured solid (70%).