A solution of compound 118 (0.55 g, 1.427 mmol) in 2 M NH3 in methanol (10 mL) was treated with Pd—C (0.05 g) and flushed with hydrogen gas. The reaction was stirred at room temperature overnight (16 h) under hydrogen atmosphere (balloon pressure). The solution was filtered through a celite bed using methanol washes (2×10 mL). The solvent was evaporated and crude was purified by column chromatography (2 M NH3 in methanol: CH2Cl2, 2.5:97.5) to obtain compound 119 (0.43 g, 84%) as a solid in 2:3 ratio of diastereomers. 1H NMR (DMSO-d6) δ: 0.99, 1.07 (2t, 3H, J=7.2, 6.6 Hz), 1.37-1.51 (m, 11H), 1.63-1.78 (m, 4H), 2.01-2.18 (m, 2H), 2.98-3.04 (m, 1H), 3.11-3.17 (m, 2H), 3.68-3.80 (m, 1H), 4.52 (brs, 2H), 6.44-6.47 (m, 1H), 6.66-6.70 (m, 1H), 6.86-6.88, 6.99-7.06 (2m, 2H), 10.23, 10.27 (2s, 1H); ESI-MS m/z (%): 380 (M+Na, 6), 358 (MH+, 5), 302 (100), 258 (54); ESI-HRMS calculated for C21H32N3O2 (MH+), Calculated: 358.2507; Observed: 358.2489.
