Reaction Steps
To a solution of Intermediate 176b (0.188 mmol) and N-ethylmethylamine (32.3 μL, 0.38 mmol) in DCM (3 mL), sodium triacetoxyborohydride (59.8 mg, 0.28 mmol) was added. The mixture was stirred at RT for 1 h. Water was added and the mixture extracted with DCM. The combined organics were passed through a phase separator and concentrated to dryness. The resulting residue was purified by RP-HPLC (C, 18, 18 mL/min, 20-85% MeCN in H2O+0.1% HCO2H) and the relevant fractions combined and concentrated to dryness. The title product was isolated as an off white solid (26.1 mg). LCMS (Method 5): Rt 3.65 min, m/z 690.6 [MH+]. 1H NMR (400 MHz, d6-DMSO): 0.91 (3H, d, J=6.4 Hz), 1.02 (3H, t, J=7.1 Hz), 1.27 (9H, s), 1.50 (2H, m), 1.66 (2H, m), 1.74-1.97 (4H, m), 1.98-2.11 (2H, m), 2.12 (3H, s), 2.40 (2H, q, J=7.1 Hz), 2.90 (1H, m), 3.16 (1H, m, obscured by solvent), 3.49 (2H, s, obscured by solvent), 4.81 (1H, m), 5.51 (1H, t, J=4.6 Hz), 6.33 (1H, s), 7.09 (1H, d, J=8.6 Hz), 7.19 (1H, dd, J=9.6, 2.1 Hz), 7.24-7.47 (8H, m), 7.64 (1H, d, J=10.2 Hz), 7.69 (1H, d, J=1.6 Hz), 8.09 (1H, s), 8.17 (1H, s).
