Dichloromethane → 5-Bromo-1-isopropyl-6-methyl-4-oxo-1,4-dihydropyridine-3-carboxylic acid

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Reaction Steps

To a solution of 1-isopropyl-6-methyl-4-oxo-1,4-dihydro-pyridine-3-carboxylic acid (preparation 1b, 1.50 g, 6.92 mmol based on 90% purity) in glacial acetic acid (10 ml) is added at room temperature bromine (0.60 mL, 11.7 mmol). After stirring for 3 d at room temperature, additional bromine (1.00 mL, 19.5 mmol) is added to the reaction mixture and stirring is continued for 2 h at room temperature. The reaction mixture is diluted with water. Upon addition of dichloromethane a precipitate forms which is filtered off and dried. Yield: 2.55 g; ESI mass spectrum: [M+H]+=274 (bromine isotope pattern); r.t. HPLC: 0.76 min (Z002_002).

Provenance & Evidence