1H NMR (400 MHz, DMSO-d6) δ
8.37 (d, J = 14.1 Hz, 2H), 8.30 (d, J = 8.6 Hz, 2H), 8.08 (t, J = 8.6 Hz, 4H), 7.82 (d, J = 9.0 Hz, 2H), 7.66 (t, J = 7.7 Hz, 2H),
7.52 (t, J = 7.5 Hz, 2H), 6.42 (d, J = 14.3 Hz, 2H), 4.35 (t, J = 7.5 Hz, 4H), 3.17 (s, 1H), 2.78 (t, J = 6.2 Hz, 4H), 1.96 (s, 12H),
1.90 (s, 15H), 1.78 (p, J = 7.7 Hz, 5H).