Hydrochloric Acid → 7-bromo-1H,2H,3H-pyrido[2,3-b][1,4]oxazin-2-one

Participants

Reaction Conditions

Reaction Steps

Ethyl [(5-bromo-3-nitropyridin-2-yl)oxy]acetate (intermediate 212) (4.3 g, 14.1 mmol) was dissolved in anhydrous THF (10 mL) and concentrated HCl (10 mL) was added at 0° C. Tin chloride (5.0 g, 26.4 mmol) was added in small portions. The reaction was stirred for 1 hr and heated at 65° C. overnight. The reaction mixture was concentrated under reduced pressure, extracted with chloroform, dried over magnesium sulfate and concentrated. Chromatography on silica gel with methanol/chloroform gave the product as a light pink solid (1.2 g, 37% yield).

Provenance & Evidence