1H NMR (400 MHz, CDCl3) δ 7.48 (d, J = 7.2 Hz, 7H), 7.38 – 7.31 (m, 8H), 4.82 (s, 2H). 13C{1H} NMR (101 MHz, CDCl3) δ 170.4, 136.4, 136.2, 129.9, 129.8, 128.8, 128.7, 128.6, 128.5, 127.8, 42.0.