1H NMR (400 MHz, CDCl3) δ 7.33 (d, J = 7.4 Hz, 2H), 7.24 (d, J = 6.5 Hz, 3H), 7.09-6.97 (m, 5H), 6.91 (d, J = 9.7 Hz, 2H), 6.70 (d, J = 7.4 Hz, 2H), 3.74 (s, 3H), 2.11 (s, 3H); 13C{H} NMR (101 MHz, CDCl3) δ 157.9, 143.8, 143.3, 138.8, 136.2, 135.1, 130.8, 130.4, 130.0, 128.1, 127.4, 126.4, 125.6, 113.2, 55.1, 23.3。