Continuous synthesis of tetrabromobisphenol A

Tetrabromobisphenol A is an excellent flame retardant.In this paper tetrabromobisphenol A was synthesized in a continuously stirred tank reactor using chlorobenzene as the solvent and bromine/hydrogen peroxide as brominating reagents.The experimental results indicated that the proper synthesis conditions were as follows:The molecular ratio of bisphenol A,bromine and hydrogen peroxide was 1∶2.1∶2.1,the reaction temperature was 60 ℃,the reaction time was 40 min,the once-through yield of tetrabromobisphenol A was 85.4%(based on weight of bisphenol A) and the melting point of the target compound was between 179.8 ℃ and 181.8 ℃.Upon recycling the solvent under the above-mentioned optimum conditions the yield of tetrabromobisphenol A was above 95.0%(based on weight of bisphenol A) with its melting point being in the range of between 178.9 ℃ and 181.5 ℃.