3,5-Dibromopyridine → 3-Bromo-5-(propan-2-yloxy)pyridine

HRID 969618Notes

Reaction equation

HRID 969618 reaction equation
[K].[CH3:2][CH:3]([CH3:5])[O-:4].[K+].Br[C:8]1[CH:9]=[N:10][CH:11]=[C:12]([Br:14])[CH:13]=1>CC(O)C.[Cu]>[Br:14][C:12]1[CH:13]=[C:8]([O:4][CH:3]([CH3:5])[CH3:2])[CH:9]=[N:10][CH:11]=1

Participants

6

Reactant 3

HCID 693693,5-DibromopyridineHCID 5462222PotassiumHCID 23663646Potassium propan-2-olate

Product 1

HCID 105848083-Bromo-5-(propan-2-yloxy)pyridineYield 71.2%

Reagents, catalysts & solvents 2

HCID 23978CopperCatalystHCID 3776IsopropanolSolvent

Procedure

Potassium metal (6.59 g, 168.84 mmol) was dissolved in dry 2-propanol (60.0 mL) under nitrogen. The resulting potassium isopropoxide was heated with 3,5-dibromopyridine (20.00 g, 84.42 mmol) and copper powder (1 g, 5% by weight of 3,5-dibromopyridine) at 140° C. in a sealed glass tube 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 obtained 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 a pale-yellow oil (12.99 g, 71.2%).

Workup

  1. extractionextracted with diethyl ether (4×200 mL)
  2. dry with materialThe combined ether extracts were dried over sodium sulfate
  3. filtrationfiltered
  4. concentrationconcentrated by rotary evaporation
  5. customThe crude product obtained
  6. customwas purified by column chromatography over aluminum oxide
  7. washeluting with ethyl acetate-hexane (1:9, v/v)
  8. concentrationconcentrated by rotary evaporation

Sources & evidence

ORD record
ord-7a5dd7414bf445a69287bd321071ce95
Source dataset
uspto-grants-2007_12
Patent number
US07307092B2

Reaction notes

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