Lithium Hydroxide → 6-Tert-butyl-2-[4-[5-[(6,6-dimethyl-4,7-dihydropyrazolo[5,1-c][1,4]oxazin-2-yl)amino]-1-methyl-6-oxo-3-pyridyl]-3-(hydroxymethyl)-2-pyridyl]-8-fluoro-phthalazin-1-one

Participants

Reaction Conditions

Reaction Steps

A mixture of 139f (160 mg, 0.25 mmol) and lithium hydroxide (60 mg, 2.5 mmol) in i-propanol/THF (1:1, 4 mL) and water (1 mL) was stirred at 30° C. for 1 h. The mixture was evaporated under reduced pressure and the residue was diluted with water (5 mL). It was then extracted with ethyl acetate (3×10 mL). The combined ethyl acetate extract was concentrated under reduced pressure and the residue was purified by reverse-phase prep-HPLC to afford 139 (60 mg, 40%) as a light yellow solid. MS-ESI: [M+H]+ 599.8. 1H NMR (500 MHz, DMSO-d6) δ 8.57 (d, J=5.0 Hz, 1H), 8.54 (d, J=2.5 Hz, 1H), 8.34 (s, 1H), 8.08 (d, J=2.5 Hz, 1H), 7.90 (d, J=1.5 Hz, 1H), 7.79-7.76 (m, 1H), 7.51 (d, J=5.0 Hz, 1H), 7.39 (d, J=2.0 Hz, 1H), 5.95 (s, 1H), 4.92 (bs, 1H), 4.73 (s, 2H), 4.42 (s, 2H), 3.80 (s, 2H), 3.60 (s, 3H), 1.40 (s, 9H), 1.26 (s, 6H).

Provenance & Evidence