High selectively oxidative bromination of toluene derivatives by the H2O2–HBr system

An aqueous solution of hydrogen peroxide and hydrogen bromide illuminated by a 60W incandescent light bulb serves as a source of bromine radicals. Various substituted toluenes (NO2, Cl, Br, H, CH3) were high selectively brominated at the benzyl position for monobromination in CH2Cl2at ice water with catalyst free. This simple but effective bromination of toluene derivatives with an aqueous H2O2–HBr system is characterized with the use of inexpensive reagents and a lower impact on the environment, which make it a good alternative to the existing bromination methods.