3,5-Dibromopyridine → 3-Bromo-5-methoxypyridine
Reaction equation
[Br:1][C:2]1[CH:3]=[N:4][CH:5]=[C:6](Br)[CH:7]=1.[CH3:9][O-:10].[Na+]>CO.[Cu]>[Br:1][C:2]1[CH:7]=[C:6]([O:10][CH3:9])[CH:5]=[N:4][CH:3]=1Participants
5
Reactant 2
Product 1
Reagents, catalysts & solvents 2
Conditions
- Temperature
- 150 °C
Procedure
A mixture of 3,5-dibromopyridine (20.00 g, 84.42 mmol), sodium methoxide (11.40 g, 211.06 mmol), and copper powder (1 g, 5% by weight of 3,5-dibromopyridine) in dry methanol was heated in a sealed glass tube at 150° C. for 14 h. The reaction mixture was cooled to ambient temperature and extracted with diethyl ether (4×200 mL). The combined ether extracts were dried over sodium sulfate, filtered, and concentrated by rotary evaporation. The crude product was purified by column chromatography over aluminum oxide, eluting with ethyl acetate-hexane (1:9, v/v). Selected fractions were combined and concentrated by rotary evaporation, producing 9.40 g (59.5%) of a colorless oil, which tended to crystallize upon cooling.
Workup
- temperatureThe reaction mixture was cooled to ambient temperature
- extractionextracted with diethyl ether (4×200 mL)
- dry with materialThe combined ether extracts were dried over sodium sulfate
- filtrationfiltered
- concentrationconcentrated by rotary evaporation
- customThe crude product was purified by column chromatography over aluminum oxide
- washeluting with ethyl acetate-hexane (1:9, v/v)
- concentrationconcentrated by rotary evaporation
Sources & evidence
- ORD record
- ord-60607681d50c474699462f2146493682
- Source dataset
- uspto-grants-2001_05
- Patent number
- US06232316B1
Reaction notes
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