¹H NMR (400 MHz, ) δ 9.74 (t, J = 2.1 Hz, 1H), 7.56 – 7.45 (m, 2H), 7.15 – 7.01 (m, 2H), 3.67 (d, J = 2.1 Hz, 2H). ¹³C NMR (101 MHz, ) δ 198.51, 132.08, 131.28, 130.75, 121.53, 49.85. GC-MS (m/z): 197。