To a solution of 2-(6-tert-butyl-8-fluoro-1-oxophthalazin-2(1H)-yl)-6-(6-(5-(morpholine-4-carbonyl)pyridin-2-ylamino)pyrimidin-4-yl)benzyl acetate (90 mg, 0.14 mmol) in 1,4-dioxane (5 mL) was added 1N NaOH (10 mL). The mixture was stirred at room temperature for 2 hrs. The mixture was acidified to pH=2, followed by addition of ethyl acetate (50 mL) and H2O (20 mL). The organic phase was washed with H2O (2×20 mL), then brine (2×20 mL) and dried over Na2SO4. After filtration and concentration, the residue was purified by prep-HPLC to afford 6-tert-butyl-8-fluoro-2-(2-(hydroxymethyl)-3-(6-(5-(morpholine-4-carbonyl)pyridin-2-ylamino)pyrimidin-4-yl)phenyl)-phthalazin-1(2H)-one (30 mg, 36%). 1H NMR (300 MHz, CD3OD): δ 8.98 (s, 1H), 8.52-8.48 (m, 2H), 8.39 (s, 1H), 7.99-7.95 (m, 1H), 7.85 (s, 1H), 7.73-7.68 (m, 5H), 4.55 (s, 2H), 3.72 (brs, 8H), 1.46 (s, 9H). LC-MS (ESI): 610.3, [M+1]+ HPLC: 97.17% at 214 nm, 99.01% at 254 nm, tR=5.761 min.
