Reaction Steps
A solution of 78 (115 mg. 0.15 mmol) and TFA (2 mL) in DCM (10 mL) was stirred at RT for 3 h. The TFA was removed by co-evaporation with DCM, diluted with a minimum of water, and the pH was adjusted to around 9 with a saturated aqueous solution of sodium bicarbonate (and few drops of 1N NaOH at the end). The aqueous solution was extracted with DCM containing traces of methanol. The organic extract was dried over anhydrous magnesium sulfate, filtered and concentrated. The crude product was purified by Biotage (SNAP 10 g cartridge; 2% of ammonium hydroxide in MeOH/DCM: 5/95 to 20/80 over 20 CV), to afford the title compound 79 (36 mg, 0.05 mmol, 36% yield) as a white sticky solid. 1H NMR (400 MHz, DMSO-d6) δ (ppm): 8.72 (s, 1H), 8.54 (d, J=1.4 Hz, 1H), 8.52 (d, J=5.3 Hz, 1H), 8.32 (s, 1H), 8.24 (d, J=8.0 Hz, 1H), 7.85 (dd, J=8.0, 2.0 Hz, 1H), 7.73 (dd, J=13.4, 2.4 Hz, 1H), 7.38 (t, J=9.1 Hz, 1H), 7.20 (bd, J=10.4 Hz, 1H), 6.64 (d, J=5.3 Hz, 1H), 6.58 (bd, J=2.2 Hz, 1H), 4.26-4.18 (m, 1H), 4.11-4.03 (m, 1H), 3.54 (s, 2H), 3.10 (d, J=5.3 Hz, 1H), 2.59-2.30 (m, 11H), 1.88-1.78 (m, 1H), 0.87 (d, J=6.8 Hz, 3H), 0.83 (d, J=6.7 Hz, 3H), 0.69-0.62 (m, 2H), 0.46-0.40 (m, 2H), NH2 is missing. MS (m/z): 662.7 (M+H).
