1H NMR (400 MHz, CDCl3) δ 7.37-7.29 (m, 4H), 6.42 (d, J = 15.7 Hz, 1H), 6.32-6.16 (m, 1H), 1.91 (d, J = 6.6 Hz, 3H), 1.35 (s, 9H); 13C{H} NMR (101 MHz, CDCl3) δ 149.7, 135.2, 130.7, 125.5, 125.3, 124.8, 34.5, 31.3, 18.5。