5.0 g of 4-pentafluorosulfanylaniline was dissolved in 20 ml of acetic acid, and, at 0 ℃, a saturated aqueous HBr solution was added. Then, at 0 ℃, a solution of 1.9 of NaNO2 in 5 ml of water was slowly added dropwise over the course of 5 minutes. The reaction mixture was stirred at 0 C. for 10 minutes and then added in portions to a suspension of 6.5 g of CuBr in 20 ml of a half-saturated aqueous HBr solution at 0 ℃. Nitrogen is liberated during this. The mixture was stirred at 0 ℃. for 30 minutes and then at RT for 1 h. It was subsequently extracted 3 times with 100 ml of HEP each time, and then the HEP was washed twice with 50 ml of a saturated aqueous Na2CO3 solution each time. The residue, after drying over MgSO4 and removal of the solvent in vacuo, was chromatographed on silica gel with HEP. 1.8 g of a colorless oil 1-Bromo-4-(pentafluorosulfanyl)benzene were obtained.
