1H NMR (400 MHz, CDCl3) δ 8.29 (d, J = 7.2 Hz, 3H), 8.18 (d, J = 8.5 Hz, 1H), 7.87 (t, J = 8.0 Hz, 2H), 7.82-7.75 (m, 3H), 7.58 (t, J = 7.5 Hz, 1H). 13C NMR (100 MHz, CDCl3) δ 154.9, 148.2, 143.7, 137.4, 132.6, 130.2, 129.9, 128.1, 127. 6, 127.5, 127.2, 118.8, 118.6, 112.8.