1H NMR (400 MHz, CDCl3) δ 9.20 (s, 1H), 8.30 (s, 1H), 8.13 (t, J = 9.3 Hz, 1H), 7.88 (d, J = 8.1 Hz, 1H), 7.70 (dd, J = 20.3, 7.6 Hz, 3H), 7.62 – 7.52 (m, 3H), 1.40 (s, 9H). 13C{1H} NMR (101 MHz, CDCl3) δ 151.3, 149.9, 147.2, 134.9, 133.7, 132.9, 129.2, 129.2, 128.1, 127.9, 127.1, 126.9, 126.2, 34.7, 31.3.