1H NMR (400 MHz, CDCl3) δ 7.95 (s, 1H), 7.77 (d, J = 8.9 Hz, 2H), 7.64 (t, J = 8.9 Hz, 2H), 7.48 – 7.37 (m, 8H), 7.32 (t, J = 7.0 Hz, 1H), 7.23 – 7.17 (m, 2H). 13C NMR (101 MHz, CDCl3) δ 196.58, 155.51, 145.29, 133.52, 133.22, 132.80, 132.71, 132.24, 130.87, 129.84, 129.42, 129.03, 128.85, 128.62, 128.48, 128.26, 127.56, 127.43, 127.36, 126.33, 125.97, 123.05, 121.31.