3-Nitrophthalic acid → 3-Aminophthalic acid

Reaction equation

[N+:1]([C:4]1[CH:12]=[CH:11][CH:10]=[C:6]([C:7]([OH:9])=[O:8])[C:5]=1[C:13]([OH:15])=[O:14])([O-])=O.[H][H]>[Pd].C(O)C>[NH2:1][C:4]1[CH:12]=[CH:11][CH:10]=[C:6]([C:7]([OH:9])=[O:8])[C:5]=1[C:13]([OH:15])=[O:14]

Participants

Procedure

10% Pd/C (2.5 g), 3-nitrophthalic acid (75.0 g, 355 mmol) and ethanol (1.5 L) were charged to a 2.5 L Parr hydrogenator, under a nitrogen atmosphere. Hydrogen was charged to the reaction vessel for up to 55 psi. The mixture was shaken for 13 hours, maintaining hydrogen pressure between 50 and 55 psi. Hydrogen was released and the mixture was purged with nitrogen 3 times. The suspension was filtered through a celite bed and rinsed with methanol. The filtrate was concentrated in vacuo. The resulting solid was reslurried in ether and isolated by vacuum filtration. The solid was dried in vacua to a constant weight, affording 54 g (84% yield) of 3-aminopthalic acid as a yellow product. 1H-NMR (DMSO-d6) δ: 3.17 (s, 2H), 6.67 (d, 1H), 6.82 (d, 1H), 7.17 (t, 1H), 8-10 (brs, 2H). 13C-NMR DMSO-d6)δ: 112.00, 115.32, 118.20, 131.28, 135.86, 148.82, 169.15, 170.09.