1H NMR (400 MHz, CDCl3) δ 7.36 (s, 1H), 6.36 (dd, J = 3.2, 1.7 Hz, 1H), 6.27 (d, J = 3.2 Hz, 1H), 5.66 (s, 1H), 5.09 (s, 1H), 3.63 – 3.52 (m, 2H), 2.65 (s, 2H), 1.80 – 1.71 (m, 6H). 13C NMR (101 MHz, CDCl3) δ 175.78, 150.71, 142.78, 140.38, 111.36, 109.31, 107.69, 52.42, 37.55, 30.04, 28.96, 23.48. HRMS (EI): calcd for C12H15NO2: 205.1103, found: 205.1107。