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

Participants

Reaction Steps

2H-Pyrido[3,2-b]-1,4-oxazin-3(4H)-one (1 g, 6.66 mmol) was refluxed with boron hydride methyl sulfide complex (2 mL) in THF (10 mL) for 30 min to give 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, 2H-pyrido[3,2-b]-1,4-oxazine was nitrated, reduced and reacted with 2,4-dichloro-5-fluoropyrimidine (400 mg) and 3-methylaminocarbonylmethyleneoxyaniline (500 mg) to give 5-fluoro-N2-(3-methylaminocarbonylmethyleneoxyphenyl)-N4-[2H-pyrido[3,2-b]-1,4-oxazin-7-yl]-2,4-pyrimidinediamine as a gray solid. 1H NMR (CDCl3): δ 2.91 (d, J=4.8 Hz, 3H), 3.55 (t, J=4.2 Hz, 2H), 4.24 (t, J=4.5 Hz, 2H), 4.49 (s, 2H), 4.90 (br, 1H), 6.51 (dd, J=2.7 and 8.1 Hz, 1H), 6.64 (s, 1H), 6.90 (dd, J=2.1 and 8.1 Hz, 1H), 7.08 (s, 1H), 7.14 (br, 1H), 7.18 (t, J=8.1 Hz, 1H), 7.28 (d, J=2.1 Hz, 1H), 7.51 (t, J=2.1 Hz, 1H), 7.93 (d, J=3.0 Hz, 1H), 7.95 (d, J=2.4 Hz, 1H); LCMS: ret. time: 11.91 min.; purity: 100%; MS (m/e): 426.12 (MH+).

Provenance & Evidence