1H NMR (400 MHz, CDCl3) δ 8.02 (d, J = 17.7 Hz, 2H), 7.91 (dd, J = 13.3, 7.7 Hz, 2H), 7.59 (d, J = 8.0 Hz, 1H), 7.48 (t, J = 7.7 Hz, 1H), 7.40 (dd, J = 15.7, 7.9 Hz, 2H), 7.35 (s, 1H), 2.49 (s, 3H). 13C NMR (100 MHz, CDCl3): δ 180.1, 152.1, 150.1, 138.5, 134.8, 134.8, 132.7, 130.9, 130.0, 129.9, 129.4, 129.1, 127.4, 126.3, 124.5, 124.0, 119.6, 17.9. HRMS (EI): calcd for C18H12Cl2O2S: 361.9935; found, 361.9936.