1H NMR (400 MHz, CDCl3) δ 8.18 (d, J = 8.5 Hz, 2H), 7.88 (s, 1H), 7.84 (d, J = 8.6 Hz, 1H), 7.80 (d, J = 8.1 Hz, 1H), 7.72 (t, J = 7.7 Hz, 1H), 7.66 (d, J = 8.3 Hz, 1H), 7.50 (t, J = 7.4 Hz, 1H), 6.99 (d, J = 8.3 Hz, 1H), 4.05 (s, 3H), 3.96 (s, 3H). 13C NMR (100 MHz, CDCl3) δ 156.8, 150.4, 149.4, 148.1, 136.8, 132.4, 129.7, 129.4, 127.5, 127.0, 126.1, 120.3, 118.7, 111.1, 110.5, 56.1, 56.0