1H NMR (500 MHz, DMSO‑d 6) δ 8.37 (s, 1H), 8.33 (s, 1H), 8.14 (s, 1H), 8.13 (s, 1H), 7.38 (br. s, 2H), 7.29 (br. s, 2H), 5.97 (d, J = 6.3 Hz, 1H), 5.84 (d, J = 5.3 Hz, 1H), 5.52–5.32 (m, 3H), 5.19 (d, J = 5.3 Hz, 1H), 4.62 (q, J = 5.4 Hz, 1H), 4.49 (dd, J = 6.3, 4.7 Hz, 1H), 4.30 (dd, J = 4.8, 2.8 Hz, 1H), 4.04 (q, J = 4.9 Hz, 1H), 3.99–3.96 (m, 1H), 3.95–3.87 (m, 1H), 3.66 (dt, J = 12.1, 4.1 Hz, 1H), 3.62–3.45 (m, 6H), 2.79 (dd, J = 14.1, 4.6 Hz, 1H), 2.71–2.52 (m, 3H), 2.45–2.28 (m, 2H), 2.14 (td, J = 7.4, 5.9 Hz, 2H), 1.58–1.46 (m, 2H).