13 g of 4-bromo-2-nitrotoluene is combined with 26 mL of acetic acid, 14.5 ml of acetic anhydride and slowly with stirring 14 mL of sulfuric acid. The solution is cooled to 5°C and a solution is made of 16.5 g of chromium (IV) oxide, 10 mL of water and 66 mL of acetic acid. The chromium solution is added to the main solution over the course of 8 h with stirring while maintaining the temperature between 5-10°C. After the addition the mixture is stirred for another hour and then poured to 200 g of ice, filtered and washed with some cold water. The product is dried and recrystallized in hot ethanol.
Addition of the chromic acid solution
The pure product