¹H NMR (400 MHz, CDCl₃) δ 8.31 (d, J = 8.7 Hz, 1H), 8.15 (d, J = 7.6 Hz, 2H), 7.88-7.76 (m, 2H), 7.51 (t, J = 7.4 Hz, 2H), 7.45 (t, J = 7.1 Hz, 1H), 7.19 (s, 1H), 2.65 (s, 3H), 2.52 (s, 3H). ¹³C NMR (100 MHz, CDCl₃) δ 156.8, 148.8, 139.7, 139.6, 134.0, 133.1, 129.2, 128.9, 128.8, 127.5, 126.9, 124.6, 117.8, 21.9, 18.5.