The rate of Sulfuryl bromide fluoride formation depends upon the rate at which the following equilibrium is established: Br2 + BrF3 = 3BrF. Sulfur dioxide (120 g) is gradually distilled at +12℃ into an iron autoclave containing a mixture of 20 ml. of bromine and 21.2 ml of BrF3. After letting stand for several days, during the autoclave is which shaken once daily, the product is distilled from the pressure vessel and collected in a quartz trap at -196℃ For purification, the SO2BrF is passed through a wash bottle filled with mercury (removal of traces of bromine and BrF3), then over NaF (removal of HF), and finally over P2O5 (removal of water). The product is then fractionated and the first cut discarded. There is no residue. The yield is 88%, based on BrF3.
