1H NMR (400 MHz, CDCl3) δ 7.41 (d, J = 7.5 Hz, 2H), 7.35 (dd, J = 16.2, 7.8 Hz, 4H), 7.29 - 7.24 (m, 1H), 6.92 (d, J = 7.6 Hz, 2H), 6.20 (s, 1H), 4.62 (d, J = 9.7 Hz, 1H), 4.53 (s, 2H), 3.81 (s, 3H), 2.76 - 2.59 (m, 2H). 13C NMR (100 MHz, CDCl3) δ 159.2, 140.1, 134.6, 134.5, 128.5, 127.4, 127.4, 124.8, 122.3, 113.9, 75.6, 66.9, 55.4, 34.8.