Short-RInChIKey=SA-FUHFF-UHFFFADPSC-TTXGKCVKGX-UHFFFADPSC-NUHFF-NUHFF-NUHFF-ZZZ

N-[4,5-dibromo-2-(tosylamino)phenyl]-4-Methyl-benzenesulfonamide (20.7 g, 36.0 mmol, 1.00 equiv) was dissolved in sulfuric acid (73.6 g, 40.0 mL, 735 mmol, 20.4 equiv). The reaction was stirred at 110 °C for 15 minutes. The crude mixture was allowed to cool for 15 minutes then it was poured on ice-water. The aqueous solution was basified using 10 M NaOH to form the precipitate.