Acetic Acid → 4-Aminobenzoic Acid

Participants

Reaction Steps

10% Pd/C (1.98 g) was added to a 450 mL hydrogenation flask, and the flask was flushed with N2. A solution of nitro benzoic acid 1 (21.9 g, 118.3 mmol) in 140 mL ethanol and acetic acid (1 mL) were added to the flask. Hydrogenation was conducted at 15 psi in a carefully controlled manner, wherein after the pressure of H2 drops to zero, the shaking of the flask was continued for a couple of minutes before re-pressurizing. After the hydrogen uptake ceased, the pressure was raised to 40 psi, and continued shaking for an additional 30 minutes to insure completion of the reduction. The catalyst was filtered through Celite, and solvent was removed in vacuo to afford amino benzoic acid 2 as an off-white solid.

Provenance & Evidence