Methyl bromoacetate → 7-Bromo-2-methyl-2H-benzo[b][1,4]oxazin-3(4H)-one

Participants

Reaction Conditions

Reaction Steps

1,8-Diazabicyclo[5.4.0]undec-7-ene (145.0 μL, 0.975 mmol) was added at room temperature to a solution of 2-amino-5-bromophenol A-1 (200.0 mg, 1.064 mmol) and methyl 2-bromoacetate (115.0 μL, 0.886 mmol) in anhydrous 1-methylpyrrolidin-2-one (4.20 mL) under an atmosphere of argon, in a 10 mL microwave reactor vial. The sealed reaction mixture was heated at 180° C. for 3 mins under microwave irradiation and then diluted with ethyl acetate (25 mL). The organic layer was washed with brine (3×20 mL), dried over anhydrous magnesium sulfate, filtered and concentrated to dryness under reduced pressure. The crude residue was purified by flash column chromatography on silica gel (hexanes:ethyl acetate gradient) to give 7-bromo-2-methyl-2H-benzo[b][1,4]oxazin-3(4H)-one A-2 (217.0 mg, Yield=100%). MS (ESI) [M+1]+ 242, 244.

Provenance & Evidence