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

Participants

Reaction Conditions

Reaction Steps

0.16 mL (2.62 mmol) of methyl iodide is added to a suspension of 0.5 g (2.18 mol) of 7-bromo-2-oxo-2,3-dihydro-1H-pyrido[2,3-b][1,4]oxazine, 0.24 g (1.09 mmol) of benzyltriethylammonium chloride and 0.75 g (5.46 mmol) of potassium carbonate in 25 mL of acetonitrile. The mixture is stirred for 6 hours at 60° C. After this time, a precipitate is removed by filtration. The filtrate is concentrated under reduced pressure and the resulting solid is taken up in 15 mL of dichloromethane and then washed successively with 20 ml of water, 10 mL of 0.1N hydrochloric acid solution, 10 mL of saturated sodium hydrogen carbonate solution and then 10 mL of water. After drying over sodium sulfate, the solution is finally concentrated under reduced pressure to give the expected product, which is used without further purification in the following step.

Provenance & Evidence