N-bromobutanimide → 5-Bromo-2-(4-bromo-2-fluorophenylamino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylic acid

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Reaction Steps

Preparation of 5-bromo-2-(4-bromo-2-fluorophenylamino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylic acid methyl ester: To a solution of 2-(4-bromo-2-fluorophenylamino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylic acid methyl ester (0.390 g, 1.34 mmol) in DMF (10 mL) was added N-bromosuccinimide (0.263, 1.48 mmol). The reaction mixture was stirred at room temperature for 25 minutes and then quenched with saturated sodium bisulfite. The reaction mixture was diluted with H2O and partitioned between EtOAc/diethyl ether and saturated NaCl. The layers were separated and the aqueous layer was reextracted with EtOAc (1×). The combined organic layers were dried (Na2SO4) and concentrated under reduced pressure. Purification by flash column chromatography (methylene chloride/EtOAc, 15:1) gave 0.424 g (85%) pure desired product as a lavender foamy solid.

Provenance & Evidence