Methyl iodide → 6-bromo-1-methyl-7-phenyl-1H-pyrido[2,3-b][1,4]oxazin-2(3H)-one

Participants

Reaction Steps

In a 15 mL reaction tube was added 6-bromo-7-phenyl-1H-pyrido[2,3-b][1,4]oxazin-2(3H)-one (1.00 g, 3.28 mmol) in anhydrous N,N-dimethylformamide (5 mL), potassium carbonate (1.359 g, 9.83 mmol) and iodomethane (0.246 mL, 3.93 mmol) to give a brown suspension. The reaction mixture was stirred at room temperature under a nitrogen atmosphere for 1 hour. The reaction mixture was diluted with saturated sodium bicarbonate solution (30 mL) and extracted into dichloromethane (3×15 mL). The combined organic phases were dried over anhydrous Na2SO4, filtered and concentrated to dryness under reduced pressure to give a brown oil. The residue was purified via Biotage chromatography (silica 50 g column, cyclohexane:ethyl acetate, gradient elution from 88:12 to 0:100) to give a pale yellow solid (780 mg, 74.6% yield). 1H NMR (500 MHz, CDCl3): 7.51-7.44 (5H, m), 7.20 (1H, s), 4.91 (2H, s), 3.36 (3H, s).

Provenance & Evidence