1035229-32-3

871101-87-0

79-04-9

1035229-32-3

1-(3-Amino-4-(benzyloxy)-2-hydroxyphenyl)ethanone (5.20 g, 20.2 mmol) and chloroacetyl chloride (1.77 mL) were reacted in DMF (30 mL) in the presence of sodium bicarbonate (3.74 g, 44.5 mmol). Chloroacetyl chloride was slowly added dropwise to the stirred reaction mixture and stirring was continued for 2 hours. Subsequently, cesium carbonate (7.90 g, 24.2 mmol) was added and the reaction mixture was heated to 100 °C and maintained for 20 hours. After completion of the reaction, the mixture was cooled to room temperature and the reaction was quenched with methanol (500 mL). After dilution with water, the mixture was extracted with ethyl acetate (2 x 200 mL) and the organic layers were combined and washed sequentially with water (3 x 300 mL) and brine. The organic layer was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The resulting solid residue was treated with ether, filtered and dried to afford 8-acetyl-5-(benzyloxy)-2H-benzo[b][1,4]oxazin-3(4H)-one (5.70 g, 19.2 mmol, 95% yield) as a beige solid.MS (ESI+) m/z: 298 [M + H]+.