Hydrogen Peroxide → 2-Amino-5-methoxy-4-methylbenzoic acid

Participants

Reaction Steps

10% Hydrogen peroxide (H2O2) (80 mL) was added dropwise to a stirring solution of 5-methoxy-6-methyl-1H-indole-2,3-dione (4.7 g, 24.6 mmol) in 3N NaOH (aq.) (100 mL). The H2O2 solution was added over a period of 1.5 h in order to keep the temperature below 35° C. The solution was then acidified to pH 4 with 2.5M sulfuric acid. A precipitate formed and was collected by filtration. The solid was washed with water and dried to give 2-amino-5-methoxy-4-methylbenzoic acid (2.7 g, 14.9 mmol, 61%).

Provenance & Evidence