¹H NMR (400 MHz, CDCl₃) δ 9.66 (s, 1H), 6.81 (d, J = 8.1 Hz, 1H), 6.71 (d, J = 8.1 Hz, 1H), 6.67 (s, 1H), 3.81 (s, 7H), 3.56 (s, 2H). ¹³C NMR (101 MHz, CDCl₃) δ 199.14, 149.03, 148.11, 123.92, 121.55, 112.40, 111.38, 55.60, 55.57, 49.77. GC-MS (m/z): 180。