1H NMR (600 MHz, DMSO‑d 6) δ 8.36 (s, 1H), 8.25 (s, 1H), 8.13 (s, 1H), 8.11 (s, 1H), 7.34 (br. s, 2H), 7.25 (br. s, 2H), 7.23–7.17 (m, 2H), 7.17–7.11 (m, 2H), 6.00 (d, J = 6.2 Hz, 1H), 5.84 (d, J = 5.0 Hz, 1H), 5.45–5.39 (m, 2H), 5.27 (d, J = 4.8 Hz, 1H), 5.12 (d, J = 5.4 Hz, 1H), 4.58 (q, J = 5.5 Hz, 1H), 4.48 (dd, J = 6.2 Hz, J = 4.8 Hz, 1H), 4.30 (td, J = 4.6 Hz, J = 2.9 Hz, 1H), 4.04 (q, J = 5.1 Hz, 1H), 4.02–3.96 (m, 2H), 3.70–3.63 (m, 2H), 3.60–3.48 (m, 4H), 2.80 (dd, J = 14.0 Hz, J = 4.5 Hz, 1H), 2.67 (dd, J = 13.9 Hz, J = 7.0 Hz, 1H), 2.61 (q, J = 6.1 Hz, 2H).