1H NMR (400 MHz, CDCl3): δ 8.14 (t, J = 9.4 Hz, 4H), 7.82 (d, J = 7.9 Hz, 2H), 7.74 (d, J = 8.0 Hz, 2H), 7.39 (s, 1H), 2.52 (s, 1H). 13C NMR (101 MHz, CDCl3) δ 180.5, 151.9, 150.4, 139.8, 134.2 (d, J = 32.8 Hz), 132.4, 130.6 (d, J = 32.8 Hz), 129.6, 126.5, 125.7 (q, J = 3.8 Hz), 125.6 (q, J = 3.8 Hz), 125.1 (d, J = 24.5 Hz), 123.8, 122.3 (d, J = 25.1 Hz), 120.8, 17.8. HRMS (EI): calcd for C20H12F6O2S: 430.0462; found, 430.0465.