Sodium hydride → 4-[2-(3,5-dibromo-4-hydroxy-phenyl)-2-oxo-ethyl]-4H-pyrido[4,3-b][1,4]oxazin-3-one

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Reaction Steps

In a 10 ml flask, 4H-pyrido[4,3-b][1,4]oxazin-3-one (50 mg, 0.33 mmol) was dissolved in N,N-dimethyl formamide (2.0 ml) and then cooled to 0□. Sodium hydride (15 mg, 0.37 mmol) was added thereto at 0□ and then stirred at room temperature for 30 minutes. The reaction mixture was cooled to 0□, 2-bromo-1-(3,5-dibromo-4-hydroxy-phenyl)-ethanone (124 mg, 0.33 mmol) was added thereto dropwise and stirred at 0□ for 30 minutes, and then the mixture was stirred at room temperature for 1 hour. The precipitates formed were filtered and washed with acetonitrile. The resulting solid was recrystallized from methanol to obtain the target compound 56, i.e., 4-[2-(3,5-dibromo-4-hydroxy-phenyl)-2-oxo-ethyl]-4H-pyrido[4,3-b][1,4]oxazin-3-one, as white solid (48 mg, 33%).

Provenance & Evidence