1H NMR (400 MHz, CDCl3) δ 7.57 – 7.49 (m, 4H), 7.42 – 7.27 (m, 10H), 2.41 (s, 3H). 13C{1H} NMR (101 MHz, CDCl3) δ 169.7, 137.8, 136.3, 130.0, 129.9, 129.7, 129.1, 128.6, 128.5, 126.1, 21.2.