Sodium hydride → 4-(3,5-dibromo-4-methoxy-benzoyl)-4H-pyrido[4,3-b][1,4]oxazin-3-one

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Reaction Steps

By the same method as in Example 56, 4H-pyrido[4,3-b][1,4]oxazin-3-one (200 mg, 1.33 mmol), sodium hydride (56 mg, 1.40 mmol) and 3,5-dibromo-4-methoxy-benzoyl chloride (437 mg, 1.33 mmol) were reacted, and then water was added thereto and the mixture was extracted with ethyl acetate. The combined organic layer was dried over anhydrous sodium sulfate (Na2SO4), filtered and evaporated under reduced pressure. The residue was purified by column chromatography on silica eluting with a solvent of ethyl acetate:methanol=9:1. The fractions containing the product were collected and evaporated to obtain the target compound 57, i.e., 4-(3,5-dibromo-4-methoxy-benzoyl)-4H-pyrido[4,3-b][1,4]oxazin-3-one, as white solid (125 mg, 21%).

Provenance & Evidence