1H NMR (400 MHz, CDCl3) δ 7.99 (t, J = 6.3 Hz, 4H), 7.52 (d, J = 7.6 Hz, 2H), 7.45 (d, J = 8.2 Hz, 2H), 7.35 (s, 1H), 2.48 (s, 3H). 13C NMR (100 MHz, CDCl3): δ 180.3, 152.6, 150.2, 139.2, 135.3, 135.1, 130.7, 129.0, 128.9, 127.8, 127.6, 123.9, 118.8, 18.0. HRMS (EI): calcd for C18H12Cl2O2S: 361.9935; found, 361.9938.