1H NMR (400 MHz, CDCl3) δ 7.37 (s, 1H), 7.29 (d, J = 7.5 Hz, 2H), 7.22 (t, J = 7.6 Hz, 4H), 7.13 (d, J = 7.3 Hz, 1H), 7.01 (d, J = 7.4 Hz, 1H), 6.80 (d, J = 8.0 Hz, 2H), 3.79 (s, 3H), 2.40 (s, 3H), 2.36 (s, 3H). 13C NMR (101 MHz, CDCl3) δ 197.26, 159.05, 154.32, 142.77, 139.19, 138.85, 133.20, 131.27, 131.19, 131.07, 130.20, 129.44, 128.47, 123.88, 123.53, 120.86, 113.62, 55.17, 21.50, 21.33.