100 g of terphenyl and 1 L of bromobenzene were placed in a 2 L reaction flask, and 174 g of liquid bromine was added to it with stirring, and the mixture was further heated to 110 °C for 40 h. At least a portion of the Br2 vapour produced by heating the terphenyl and liquid bromine is condensed back to the reaction flask using low temperature (-10-0 °C) condensation, and at least a portion of the Br2 and hydrogen bromide vapour is absorbed using water. After cooling to 25 °C, the reaction solution of terphenyl and liquid bromine was poured into 2 L of methanol, stirred for 0.5 hours, filtered, and the filter cake was washed at least once with 800 mL of methanol. The filtered cake was dried in a forced air oven at 60 °C for 2 hours. The dried crude product was added to 200 mL of toluene and refluxed for 12 hours. After hot filtration, the filter cake was rinsed once with 200 mL of toluene and drained. The dried filter cake was added to 200 mL of toluene and refluxed for 4 hours. After hot filtration, the filter cake was rinsed once with 200 mL of toluene.Drain.The obtained filter cake was placed in a blast oven and dried at 80 °C for 24 hours to obtain 119 g of a white solid. The product was 4,4''-Dibromo-p-terphenyl, and the yield was 70.6 percent.
