Reaction Steps
To a solution of 161g (120 mg, 0.18 mmol) in methanol (20 mL) was added NaBH4 (21 mg, 0.54 mmol) at room temperature. After the reaction was stirred for 1 h, LCMS indicated the reaction was complete. Then the mixture was poured into water (20 mL) and concentrated under reduced pressure. The residue was extracted with dichloromethane (3×40 mL). The combined organic layer was washed with brine (20 mL), dried over Na2SO4, filtered, and concentrated. The residue solid was purified by prep-HPLC to afford 161 (97 mg, 81%) as white solid. MS-ESI: [M+H]+ 665. 1H NMR (500 MHz, CDCl3) δ 8.63 (s, 1H), 8.50 (d, J=5.0 Hz, 1H), 7.93 (s, 1H), 7.84-7.82 (m, 2H), 7.35 (d, J=4.5 Hz, 1H), 7.28 (s, 1H), 6.82 (d, J=9.0 Hz, 1H), 6.32 (s, 1H), 5.01-4.99 (m, 1H), 4.73-4.64 (m, 5H), 4.45-4.40 (m, 1H), 4.30 (t, J=12.0 Hz, 1H), 3.94-3.91 (m, 1H), 3.85-3.83 (m, 2H), 3.72 (s, 3H), 3.55-3.53 (m, 1H), 3.34-3.32 (m, 1H), 3.14-3.12 (m, 2H), 3.04-2.92 (m, 2H), 2.84-2.82 (m, 2H), 2.59-2.57 (m, 1H), 2.46-2.44 (m, 2H), 2.38-2.36 (m, 1H), 2.06-2.01 (m, 2H), 1.90-1.86 (m, 2H), 1.68-1.66 (m, 1H), 1.43-1.39 (m, 1H), 0.82 (t, J=7.5 Hz, 3H).
