Preparation of Tetrabromobisphenol A by Sodium Nitrite Catalyzed Aerobic Oxybromination of Bisphenol A

A novel and efficient catalytic system for the aerobic oxybromination of bisphenol A to the corresponding tetrabromobisphenol A utilizing a combination of molecular bromine and molecular oxygen as the reactants and sodium nitrite as the catalyst was developed.Under the optimum conditions,n(bisphenol A)∶n(Br2)∶n(NaNO2)=1∶2.15∶0.1,reaction temperature 25 ℃ and reaction time 2 h,yield of tetrabromobisphenol A is 95.0%(based on bisphenol A).The newly developed catalytic system has many advantages,such as high bromine atom economy and innocuous water as the only by-product.