Increasing the Selectivity of Bromination of Aromatic Compounds Using Br2/SiO2

In the presence of silica, a number of aromatic hydrocarbons such as toluene, o-, m-, and p-xylene, anthracene and phenol are brominated by Br2 under mild conditions; for example Br2/SiO2 brominates naphthalene readily at 25 °C to 1-bromonaphthalene. For comparison, we have also brominated all of the substrates in with bromine in the absence of silica gel.