General procedure for the synthesis of 3-bromo-5-(methylsulfonyl)aniline from 1-bromo-3-(methylsulfonyl)-5-nitrobenzene: 1-bromo-3-(methylsulfonyl)-5-nitrobenzene (100 mg, 0.4 mmol) was dissolved in tetrahydrofuran (THF, 10 mL). Raney nickel catalyst was added and the hydrogenation reaction was carried out under 1 bar hydrogen pressure. Upon completion of the reaction, the mixture was filtered to remove the catalyst and the filtrate was subsequently concentrated. 3-Bromo-5-(methylsulfonyl)aniline (30 mg, 0.16 mmol, 40% yield) was finally obtained as a yellow solid.
