1H NMR (400 MHz, DMSO-d6) δ 11.44 (s, 1H), 8.18 (d, J = 8.1 Hz, 1H), 7.81 – 7.55 (m, 6H), 7.44 (d, J = 7.6 Hz, 2H), 6.75 (d, J = 8.5 Hz, 1H). 13C NMR (101 MHz, DMSO-d6) δ 160.00, 156.01, 152.19, 139.95, 136.55, 135.24, 135.17, 134.50, 131.83, 130.79, 130.27, 128.29, 126.47, 117.22. LCMS m/z: 290 [M+], 291 found. IR (cm-1): 3153.63, 3095.11, 3033.15, 2826.57, 2552.63, 2365.45, 2191.48, 1958.40, 1660.97, 1581.04, 1506.84, 1490.91, 1268.62, 1195.79, 877.15