Water → 5-fluoro-1H-pyrido[2,3-d][1,3]oxazin-2(4H)-one

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Reaction Steps

The solution of the product of Step C (120 mg, 0.4 mmol) in DMSO (1 mL) was stirred at 60° C. for 4 hours under N2. Then water (10 mL) was added and extracted with ethyl acetate (3×15 mL). The combined organic phase was washed with brine, dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was purified by prep-TLC (EtOAc:PE=1:1) to give the title compound (20 mg, 30%) as a solid. 1H-NMR (600 MHz, DMSO-d6) δ 10.95 (s, 1H), 8.21-8.18 (m, 1H), 6.97-6.94 (m, 1H), 5.37 (s, 2H) ppm. MS: M/e 169 (M+1)+.

Provenance & Evidence