6-Bromo-1,4-dihydro-2H-pyrido-[2,3-d][1,3]oxazin-2-one synthesis

Yield:335032-38-7 51%

Reaction Conditions:

with sodium methylate in methanol;

Steps:

41.c Preparation of 6-bromo-2-oxo-1,4-dihydro-2 H -pyrido[2,3- d ]-1,3-oxazine

c) 6-Bromo-2-oxo-1,4-dihydro-2H-pyrido[2,3-d]-1,3-oxazine To a stirred solution of 2-amino-5-bromo-3-(hydroxymethyl)pyridine (3.0 g, 15 mmole) in methanol (30 mL) was added dimethyl carbonate (5 mL, 60 mmole) and sodium methoxide (25 wt% solution in methanol, 4 mL, 17.4 mmole). The reaction was heated at reflux for 18 hr, cooled to RT, and concentrated to dryness. The remaining residue was triturated with saturated aqueous NH₄Cl (50 mL), filtered, washed with cold H₂O (50 mL), and dried under vacuum to give the title compound (1.75 g, 51%) as a beige solid: LCMS (ES) m/e 229.0 (M + H)⁺; ¹H NMR-(400 MHz, DMSO-d₆) δ 10.90 (s, 1 H), 8.31 (s, 1 H), 7.90 (s, 1 H), 5.31 (s, 2 H).

References:

EP1226138,2004,B1