Using method C with 30 (167 mg, 0.16 mmol, 1.00 eq) and a 0–40% linear gradient of acetonitrile in TEAAc buffer 50 mM, pH 7 for purification, 10 (25 mg, 20%) was obtained as a white powder with 97% purity determined by HPLC analysis at 260 nm. 1H NMR (500 MHz, DMSO‑d 6) δ 8.32 (s, 1H), 8.28 (s, 1H), 8.13 (s, 2H), 7.77 (d, J = 9.0 Hz, 1H), 7.44 (dd, J = 8.5 Hz, J = 2.6 Hz, 1H), 7.34 (br. s, 2H), 7.29 (br. s, 2H), 6.99 (dd, J = 9.0 Hz, J = 2.6 Hz, 1H), 5.95 (d, J = 5.2 Hz, 1H), 5.83 (d, J = 5.5 Hz, 1H), 5.65 (br. s, 1H), 5.49 (br. s, 1H), 5.38 (t, J = 5.7 Hz, 1H), 5.27 (br. s, 1H), 4.66 (t, J = 5.2 Hz, 1H), 4.37 (t, J = 5.1 Hz, 1H), 4.33–4.26 (m, 1H), 4.17–4.08 (m, 2H), 3.93 (q, J = 3.6 Hz, 1H), 3.84 (s, 3H), 3.80–3.62 (m, 3H), 3.60–3.37 (m, 5H). 13C NMR (125 MHz, DMSO‑d 6) δ 162.6, 156.1, 156.2, 152.6, 152.6, 149.3, 149.0, 148.9, 139.9, 139.8, 131.5, 123.3, 119.2 (2C), 116.7, 109.7, 87.8, 86.3, 85.8, 81.8, 81.5, 72.5, 71.5, 68.1, 66.4, 61.1, 56.6, 50.3, 47.1. HRMS (ESI+): m/z calcd for C29H35N12O12S [M+H]+: 775.2218, Found 775.2225.