Ethyl Acetate → 4-(Diethylboranyl)pyridine

HRID 550317Notes

Reaction equation

HRID 550317 reaction equation
[Li+].CCC[CH2-].Br[C:7]1[CH:12]=[CH:11][N:10]=[CH:9][CH:8]=1.[CH2:13]([B:15]([CH2:18][CH3:19])OC)[CH3:14].C(OCC)(=O)C>CCOCC.[Cl-].[Na+].O>[CH2:13]([B:15]([CH2:18][CH3:19])[C:7]1[CH:12]=[CH:11][N:10]=[CH:9][CH:8]=1)[CH3:14]

Participants

7

Reactant 4

HCID 8857Ethyl AcetateHCID 142684-BromopyridineHCID 61028n-Butyl lithiumHCID 522516Diethylmethoxyborane

Product 1

HCID 133188714-(Diethylboranyl)pyridine

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolvent3×HCID 57417360Sodium chloride; waterSolvent

Conditions

Temperature
-40 °C

Procedure

N-Butyllithium (1.6M in hexanes, 20 ml) was added to dry ether (100 ml) and cooled to −40° C. under nitrogen. The solution was stirred and a solution of 4-Bromopyridine (32 mmols) dissolved in dry ether was added drop wise. The ethereal solution was stirred for 30 minutes at −40° C. then cooled to −70° C. Diethyl methoxy borane (4.6 ml) dissolved in dry ether (50 ml) was added drop wise and the mixture was allowed to warm to room temperature over night. Ethyl acetate (100 ml) and brine (70 ml) were added to the resulting brown solution and the organic layer was separated. This was dried over magnesium sulfate, filtered and evaporated to yield a brown tar. The product was purified by column chromatography on silica eluted with toluene to yield (0.94 g, 6.4 mmols) of Diethyl (4-pyridyl borane) (I) as a white solid.

Workup

  1. additionwas added drop wise
  2. stirringThe ethereal solution was stirred for 30 minutes at −40° C.
  3. temperaturethen cooled to −70° C
  4. additionwas added drop wise
  5. temperatureto warm to room temperature over night
  6. customthe organic layer was separated
  7. dry with materialThis was dried over magnesium sulfate
  8. filtrationfiltered
  9. customevaporated
  10. customto yield a brown tar
  11. customThe product was purified by column chromatography on silica
  12. washeluted with toluene

Sources & evidence

ORD record
ord-aef0eb0048104713961a7ed5854b4671
Source dataset
uspto-grants-2011_05
Patent number
US07947255B2

Reaction notes

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