1H NMR (400 MHz, CDCl3) δ 7.34 (s, 5H), 7.26 – 7.19 (m, 3H), 7.07 – 6.97 (m, 3H), 5.72 (s, 1H), 2.22 (s, 3H), 1.79 (s, 3H). 13C NMR (101 MHz, CDCl3) δ 149.15, 140.21, 140.19, 139.89, 137.90, 129.87, 128.49, 128.18, 128.14, 128.00, 127.67, 123.04, 105.44, 13.49, 11.22. HRMS (EI): calcd for C19H18N2: 274.1470, found: 274.1469。