General procedure for the synthesis of 2-aminodiphenyl sulfone from 2-nitrodiphenyl sulfone: 5.22 g (0.09315 mol) of iron powder was added in batches to a 60 mL suspension of acetic acid containing 4.9 g (0.01863 mol) of 2-nitrodiphenyl sulfone. The reaction mixture was stirred at 70°C for 3 hours, followed by cooling and filtration to remove inorganic impurities. To the filtrate was added 100 mL of water, and the precipitate precipitated was filtered, washed with water, and dried under vacuum to give 4 g (92% yield) of 2-(phenylsulfonyl)aniline (10f). The product was analyzed by mass spectrometry (LS MC m/z 234 (M + 1)) and 1H NMR (DMSO-d6, 400 MHz) δ 7.91 (d, J = 8Hz, 2H), 7.67 (t, J = 9.6Hz, 2H), 7.58 (t, J = 7.6Hz, 2H), 7.29 (t, J = 7.2Hz, 1H), 6.77 (d, J = 8.4 Hz, 1H), 6.67 (t, J = 7.6 Hz, 1H), 6.12 (s, 2H) confirmed.
