1H NMR (400 MHz, CDCl3) δ 7.44 (d, J = 7.5 Hz, 2H), 7.39-7.32 (m, 2H), 7.29 (d, J = 6.4 Hz, 1H), 6.75 (dd, J = 17.6, 10.9 Hz, 1H), 5.78 (d, J = 17.4 Hz, 1H), 5.27 (d, J = 10.9 Hz, 1H). 13C{H} NMR (101 MHz, CDCl3) δ 137.6, 136.9, 128.5, 127.8, 126.2, 113.8。