Hydrochloric Acid → 2-Amino-4,6-dimethoxybenzoic acid

Participants

Reaction Conditions

Reaction Steps

To a heated mixture (in an oversized flask) of 13 g (63 mmol) 4,6-dimethoxyindole-2,3-dione prepared in Example 1 and 108 ml of 33% NaOH solution was carefully added 20 ml of a 30% solution of H2O2. A vigorous exothermic reaction occurs. After all H2O2 was added, the reaction mixture was maintained at 100° C. for an additional 10 min. The pH of the solution was brought to 8 with concentrated HCl and acidified to pH 5-6 with acetic acid. The solid was filtered, washed with water and dried to yield 6.2 g of 4,6-dimethoxyanthranilic acid as a pale brown solid (50% yield).

Provenance & Evidence