1H NMR (400 MHz, CDCl3) δ 7.34-7.14 (m, 2H), 6.84 (d, J = 8.5 Hz, 2H), 6.36 (d, J = 15.6 Hz, 1H), 6.22-6.00 (m, 1H), 3.81 (s, 3H), 1.87 (d, J = 6.5 Hz, 3H); 13C{H} NMR (101 MHz, CDCl3) δ 158.6, 130.8, 130.3, 126.8, 123.5, 113.9, 55.3, 18.4。