6-Bromo-1,1,4,4-tetramethyl-1,2,3,4-tetrahydronaphthalene

108-86-1

6223-78-5

27452-17-1

The reactor was cooled to 0 °C under nitrogen protection. A mixture (90 mL) containing 2,5-dichloro-2,5-dimethylhexane (110 g, 600 mmol) and aluminum bromobenzenesulfonate (7 g, 52.5 mmol) was added slowly and dropwise to the reactor. After dropwise addition, stirring of the reaction mixture was continued for about 20 minutes. Subsequently, the reaction mixture was extracted with 1 L of a mixed solution of ether and hexane (1:1 v/v). The organic layer was washed sequentially with ice water, 10% hydrochloric acid and 100 mL of brine. After separation of the organic layer, the solvent was removed by concentration under reduced pressure. The residue was dried with magnesium sulfate to give a brown oil. Finally, the target product 6-bromo-1,1,4,4-tetramethyl-1,2,3,4-tetrahydronaphthalene was purified by methanol crystallization to obtain 120 g in 80% yield.