1H NMR (400 MHz, CDCl3) δ 7.52 (s, 1H), 7.44 – 7.37 (m, 3H), 7.32 – 7.23 (m, 7H), 6.72 (d, J = 2.4 Hz, 1H), 5.87 (d, J= 2.5 Hz, 1H), 2.30 (s, 3H). 13C NMR (101 MHz, CDCl3) δ 149.18, 140.15, 137.96, 129.81, 129.63, 129.19, 128.97, 128.25, 127.88, 127.39, 127.00, 125.33, 106.54, 13.29. HRMS (EI): calcd for C18H16N2: 260.1313, found: 260.1310。