1H NMR (400 MHz, CDCl3) δ 7.47 (d, J = 7.1 Hz, 4H), 7.42 – 7.26 (m, 11H), 3.93 (t, J = 7.7 Hz, 2H), 3.03 (t, J = 7.7 Hz, 2H). 13C{1H} NMR (101 MHz, CDCl3) δ 170.6, 138.1, 136.1, 129.8, 129.8, 128.9, 128.6, 128.6, 128.5, 126.6, 39.6, 34.6.