1H NMR (400 MHz, CDCl3) δ 7.15-7.26 (m, 3H), 7.03 (d, J = 7.4 Hz, 1H), 6.40 (d, J = 15.9 Hz, 1H), 6.20-6.29 (m, 1H), 2.36 (s, 3H), 1.90 (d, J = 6.5 Hz, 3H); 13C{H} NMR (101 MHz, CDCl3) δ 137.9, 137.9, 131.1, 128.3, 127.5, 126.6, 125.4, 122.9, 21.4, 18.5。