To a beaker add 1.2 mL of conc. sulfuric acid and 14.5 mL of water to this solution 1.96 g of anthranilic acid is added with heating the solution to almost boiling, thereafter the solution is cooled down to 5°C in a freezer. A solution is prepared from 1.07 g of sodium nitrite and 5 mL of water which is slowly dropped to the cold solution of anthranilic acid. Then a solution is made by dissolving 3.6 g of potassium iodide in 18 mL of 1M sulfuric acid, thereafter the solution is slowly poured into the earlier solution. With stirring the solution is boiled for 6 minutes, cooled down in a freezer and filtered. The crude product is recrystallized from hot 1:1 ethanol-water solution then recrystallized twice from hot water. Decolorizing can be used to make the product more pure and white.
The crude product crystallizing out from the mother solution
The crude product
The recrystallized product