1H NMR (400 MHz, CDCl3) δ 7.50-7.37 (m, 2H), 7.10-6.94 (m, 2H), 5.32 (s, 1H), 5.08 (t, J = 1.5 Hz, 1H), 2.15 (t, 3H).13C{H} NMR (101 MHz, CDCl3) δ 162.3 (d, J = 246.3 Hz), 142.2, 137.3 (d, J = 3.3 Hz), 127.1 (d, J = 8.0 Hz), 115.0 (d, J = 21.3 Hz), 112.2 (d, J = 1.5 Hz), 21.9。