1H NMR (400 MHz, CDCl3) δ 9.75 (s, 1H), 7.68 – 6.92 (m, 4H), 3.74 (s, 2H). 13C NMR (101 MHz, CDCl3) δ 197.97, 161.16 (d, J = 246.2 Hz), 131.63 (d, J = 4.3 Hz), 129.43 (d, J = 8.0 Hz), 124.45 (d, J = 3.7 Hz), 119.44 (d, J = 16.3 Hz), 115.55 (d, J = 21.6 Hz), 43.92. GC-MS (m/z): 138。