1H NMR (400 MHz, CDCl3) δ 7.86 (s, 1H), 7.51-7.39 (m, 5H), 7.39-7.33 (m, 1H), 2.17 (s, 3H); 13C{H} NMR (101 MHz, CDCl3) δ 174.4, 141.1, 135.6, 129.8, 128.7, 128.4, 127.6, 13.7。