1H NMR (400 MHz, CDCl3) δ 7.68-7.37 (m, 7H), 7.12-6.97 (m, 2H), 5.56 (dd, J = 17.3, 1.4 Hz, 2H), 3.93 (s, 3H). 13C{H} NMR (101 MHz, CDCl3) δ 159.3, 149.5, 141.7, 133.9, 129.3, 128.2, 128.0, 127.5, 113.5, 112.8, 55.0。