¹H NMR (400 MHz, CDCl₃) δ 9.93 (s, 1H), 7.43 – 7.31 (m, 5H), 7.23 (t, J = 11.3 Hz, 2H), 7.14 (t, J = 8.5 Hz, 2H), 4.88 (s, 1H). ¹³C NMR (101 MHz, CDCl₃) δ 197.91, 135.73, 134.81, 133.62, 130.42, 130.20, 129.15, 129.08, 127.84, 63.35. GC-MS (m/z): 230。