1H NMR (400 MHz, CDCl3) δ 9.24 (s, 1H), 9.08 (s, 2H), 8.05 (s, 1H), 7.99 (d, J = 8.5 Hz, 1H), 7.91 (dd, J = 13.7, 4.4 Hz, 2H), 7.68 (d, J = 8.4 Hz, 1H), 7.58 – 7.54 (m, 2H). 13C NMR (101 MHz, CDCl3) δ 157.42, 155.06, 134.30, 133.47, 133.15, 131.46, 129.36, 128.26, 127.75, 126.96, 126.92, 126.35, 124.25.
