1,1'-Carbonyldiimidazole → (S)-N-(3-chloropropyl)-5-(4-(5-fluoro-2-methoxypyridin-3-yl)-2-oxooxazolidin-3-yl)pyrazolo[1,5-a]pyrimidine-3-carboxamide

To a solution of (S)-N-(3-chloropropyl)-5-(1-(5-fluoro-2-methoxypyridin-3-yl)-2-hydroxyethylamino)pyrazolo[1,5-a]pyrimidine-3-carboxamide (60 mg, 0.14 mmol) in ACN (2 mL) was added CDI (35 mg, 0.21 mmol). The solution was stirred at ambient temperature for 16 hours then partitioned between saturated NH4Cl solution (20 mL) and EtOAc (10 mL) and the layers separated. The aqueous layer was extracted with EtOAc (2×10 mL) and the combined organic phases were washed with brine (10 mL), dried over Na2SO4, filtered and concentrated. The residue was purified by flash column chromatography eluting with 1% MeOH/DCM to afford (S)-N-(3-chloropropyl)-5-(4-(5-fluoro-2-methoxypyridin-3-yl)-2-oxooxazolidin-3-yl)pyrazolo[1,5-a]pyrimidine-3-carboxamide (37 mg, 58% yield) as a white solid. MS (apci) m/z=449.0 (M+H).