1H NMR (400 MHz, CDCl3) δ 7.56 – 7.50 (m, 5H), 7.44 – 7.35 (m, 9H). 13C{1H} NMR (101 MHz, CDCl3) δ 169.1, 136.4, 134.6, 132.9, 130.1, 130.0, 130.0, 128.6, 128.3, 127.8, 126.2, 124.1.