1H NMR (400 MHz, CDCl3): δ 7.90 (t, J = 8.4 Hz, 4H), 7.68 (d, J = 7.7 Hz, 2H), 7.60 (d, J = 7.9 Hz, 2H), 7.34 (s, 1H), 2.48 (s, 1H). 13C NMR (100 MHz, CDCl3): δ 180.5, 152.7, 150.2, 135.7, 132.0, 131.8, 130.8, 128.2, 127.8, 123.9, 123.4, 119.0, 18.0. HRMS (EI): calcd for C18H12Br2O2S: 449.8925; found, 449.8924.