1H NMR (400 MHz, CDCl3) δ 7.54 (d, J = 9.3 Hz, 2H), 7.42-7.35 (m, 6H), 7.34-7.25 (m, 2H), 6.85 (s, 1H), 2.30 (s, 3H); 13C{H} NMR (101 MHz, CDCl3) δ 144.0, 138.3, 137.4, 129.1, 128.3, 128.2, 127.7, 127.2, 126.4, 126.0, 17.5。