6-Nitro-2H-pyrido[3,2-B][1,4]oxazin-3(4H)-one → 6-nitro-2H-pyrido[3,2-b]-1,4-oxazine

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Reaction Steps

6-Nitro-2H-pyrido[3,2-b]-1,4-oxazin-3(4H)-one (500 mg) was refluxed with boron hydride methyl sulfide complex (1 mL) in THF (10 mL) for 30 min to give 6-nitro-2H-pyrido[3,2-b]-1,4-oxazine. In a manner analogous to the preparation of 5-fluoro-N2-(3-methylaminocarbonylmethyleneoxyphenyl)-N4-[2H-pyrido[3,2-b]-1,4-oxazin-3(4H)-one-7-yl]-2,4-pyrimidinediamine, 6-nitro-2H-pyrido[3,2-b]-1,4-oxazine was reduced and reacted with 2,4-dichloro-5-fluoropyrimidine (500 mg) and 3-methylaminocarbonylmethyleneoxyaniline (500 mg) to give 5-fluoro-N2-(3-methylaminocarbonylmethyleneoxyphenyl)-N4-[2H-pyrido[3,2-b]-1,4-oxazin-6-yl]-2,4-pyrimidinediamine as a gray solid. 1H NMR (CD3OD): δ 2.81 (s, 3H), 3.48 (t, J=4.5 Hz, 2H), 4.14 (t, J=4.5 Hz, 2H), 4.44 (s, 2H), 6.60 (ddd, J=1.5 and 2.7 and 7.5 Hz, 1H), 6.94 (d, J=8.1 Hz, 1H), 7.14 (d, J=3.0 Hz, 1H), 7.17 (t, J=7.8 Hz, 1H), 7.40 (d, J=8.9 Hz, 1H), 7.42 (t, J=2.1 Hz, 1H), 7.92 (d, J=3.3 Hz, 1H); 19F NMR (282 MHz, CD3OD): δ−168.20; LCMS: ret. time: 25.49 min.; purity: 97.56%; MS (m/e): 426.23 (MH+).

Provenance & Evidence