The effect of substitutes on chemoselective C-H functionalization of arens by H2O2-HBr in water

A novel, practical and environmentally friendly method has been developed for bromination of toluene derivatives by using H2O2-HBr system in water as a green solvent with a mild condition. This direct and straightforward method approaches to a chemoselective and regioselective substitution. Different toluene derivatives were used in which, type of functional group has affected on chemoselectivity and the situation of them has affected on regioselectivity of the reaction. Bromination was done on aromatic rings and alkane chain by different reaction conditions.  Brominated toluene derivatives are isolated in moderate to high yields, different spectroscopic techniques were used to characterize the compounds, including GC-MS, 1H NMR, and 13C NMR.