1H NMR (400 MHz, CDCl3): δ 8.19 (s, 1H), 8.17 (s, 1H), 7.96 (dd, J = 15.7, 7.8 Hz, 2H), 7.74 (d, J = 7.9 Hz, 1H), 7.52 (t, J = 9.6 Hz, 1H), 7.41 (t, J = 7.9 Hz, 1H), 7.38-7.30 (m, 2H), 2.49 (s, 3H). 13C NMR (100 MHz, CDCl3): δ 179.9, 152.0, 150.1, 138.7, 135.6, 132.3, 132.0, 131.1, 130.2, 130.1, 129.1, 127.8, 124.9, 123.9, 122.9, 122.8, 119.6, 17.9. HRMS (EI): calcd for C18H12Br2O2S: 449.8925; found, 449.8929.