1H NMR (400 MHz, CDCl3) δ 7.53 (s, 1H), 7.40 (d, J = 7.9 Hz, 2H), 7.32 (t, J = 8.9 Hz, 3H), 7.13 (d, J = 7.6 Hz, 2H), 7.09 (d, J = 7.6 Hz, 2H), 7.03 (d, J = 7.7 Hz, 1H), 2.33 (s, 3H). 13C NMR (101 MHz, CDCl3) δ 194.98, 152.90, 143.10, 138.25, 135.43, 135.03, 132.96, 132.68, 132.27, 130.95, 129.87, 129.73, 129.29, 129.07, 127.05, 123.67, 121.74, 21.35.