Reaction Steps
To a solution of methyl(2S)-2-(tert-butoxy)-2-{15-fluoro-4,26-dimethyl-10-oxo-19,25-dioxa-1,7,11,31-tetraazapentacyclo[24.2.2.16,9.02,7.013,18]hentriaconta-2,4,6(31),8,13(18),14,16-heptaen-3-yl}acetate (22 mg, 0.035 mmol, 1 equiv) in 9:1 MeOH:water (1 mL) was added LiOH.H2O (44 mg, 1.06 mmol, 30 equiv). The reaction was heated to 60° C. for 1 h. Upon cooling to ambient temperature, the reaction was filtered and purified via preparative LC/MS with the following conditions: Column: XBridge C18, 19×mm, 5-μm particles; Mobile Phase A: 5:95 acetonitrile:water with 10-mM ammonium acetate; Mobile Phase B: 95:5 acetonitrile:water with 10-mM ammonium acetate; Gradient: 20-60% B over 20 minutes, then a 5-minute hold at 100% B; Flow: 20 mL/min to provide the product (10.2 mg, 46%). 1H NMR (500 MHz, DMSO-d6) δ 8.72-8.62 (m, 1H), 8.01 (s, 1H), 7.29-7.18 (m, 2H), 7.05 (dd, J=8.4, 2.9 Hz, 1H), 6.97 (dd, J=8.7, 4.4 Hz, 1H), 5.91 (br. s., 1H), 4.31 (br. s., 2H), 4.08-3.95 (m, 2H), 3.86-3.79 (m, 2H), 3.50-3.40 (m, J=5.2 Hz, 2H), 2.95 (d, J=7.9 Hz, 1H), 2.60 (d, J=7.6 Hz, 1H), 2.38 (s, 3H), 1.89-1.60 (m, 10H), 1.21 (s, 3H), 1.17 (s, 9H); LCMS (ESI, M+1): 611.5. —OH
