¹H NMR (400 MHz, CDCl₃) δ 9.64 (s, 1H), 6.90 (s, 2H), 3.71 (s, 2H), 2.27 (s, 3H), 2.24 (s, 6H). ¹³C NMR (101 MHz, CDCl₃) δ 199.01, 137.11, 136.94, 129.10, 126.17, 44.70, 20.84, 20.32. GC-MS (m/z): 162。