Reaction Steps
To a solution of 137a (200 mg, 0.29 mmol) in propan-2-ol (8 mL), tetrahydrofuran (8 mL), and water (2.0 mL) was added LiOH (690 mg, 29 mmol). The mixture was stirred at 30° C. for 2 h. It was then evaporated and the residue was purified by reverse-phase prep-HPLC to afford 137 (143 mg, 76%) as a white solid. LCMS: (M+H)+ 651.4. 1H NMR (500 MHz, DMSO-d6) δ 8.63 (d, J=2.0, 1H), 8.49 (d, J=5.0, 1H), 8.45 (s, 1H), 7.84 (d, J=2.5, 1H), 7.47 (d, J=2.0, 1H), 7.37-7.39 (m, 1H), 7.35 (d, J=5.5, 1H), 7.25 (d, J=9.5, 1H), 6.58 (s, 1H), 4.95 (t, J=4.0, 1H), 4.54-4.58 (m, 2H), 4.40-4.49 (m, 4H), 4.11-4.26 (m, 3H), 3.86-3.88 (m, 1H), 3.68 (s, 1H), 3.61 (s, 3H), 3.37-3.42 (m, 1H), 3.08-3.11 (m, 1H), 2.95 (t, J=9.0, 1H), 2.62-2.67 (m, 1H), 2.54-2.59 (m, 2H), 2.48 (t, J=6.0, 2H), 2.30-2.36 (m, 2H), 2.19 (t, J=8.0, 1H), 1.81 (s, 2H), 1.68-1.72 (m, 2H), 0.93 (d, J=6.0, 3H)
