1,2-Dibromoethane → HCID 67370279, compound

HRID 1925791Notes

Reaction equation

HRID 1925791 reaction equation
[Mg].BrCCBr.Br[CH2:7][CH2:8][CH2:9][CH2:10]Br.[CH3:12][C:13](=[C:21]([CH3:23])[CH3:22])[CH2:14][CH2:15][C:16]([O:18]CC)=O.[Cl-].[NH4+]>C(OCC)C>[CH3:12][C:13](=[C:21]([CH3:22])[CH3:23])[CH2:14][CH2:15][C:16]1([OH:18])[CH2:10][CH2:9][CH2:8][CH2:7]1

Participants

7

Reactant 5

HCID 78391,2-DibromoethaneHCID 80561,4-DibromobutaneHCID 25517Ammonium ChlorideHCID 5462224MagnesiumHCID 86647572HCID 86647572, compound

Product 1

HCID 67370279HCID 67370279, compoundYield 78.2%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent3×

Procedure

Magnesium turnings (9.53 g, 0.39 mol) were covered with dry diethyl ether (50 ml) at room temperature under nitrogen. 1,2-Dibromoethane (0.5 ml) was added in one portion. As soon as a visible reaction had started (bubbling), magnetic stirring was switched on and a solution of 1,4-dibromobutane (50 g, 0.225 mol) in dry diethyl ether (360 ml) was added at a rate such as to maintain a constant reflux (1 hour). The reaction was further refluxed for 1 hour before cooling in an ice-water bath. Ethyl 4,5-dimethyl-4-hexenoate (26.5 g, 0.156 mol) in dry diethyl ether (30 ml) was added dropwise. Then the reaction was warmed up to room temperature and the reaction was refluxed for 1 hour. It was recooled in an ice-water bath before adding a saturated aqueous ammonium chloride solution (250 ml, slowly). After warming up to room temperature and shaking vigorously, the phases were separated. The organic phase was washed with aqueous saturated bicarbonate (250 ml) and water (500 ml). Each aqueous phase was re-extracted with diethyl ether (250 ml). Combined extracts were dried over anhydrous sodium sulfate. The product was purified by column chromatography on silica gel (eluting with heptanes/ethyl acetate 11:1 to 3:1) followed by bulb-to-bulb distillation (110° C./1 mbar). 22.62 g of the title compound (99.6% pure, 0.122 mol, 78%) were obtained.

Workup

  1. customAs soon as a visible reaction
  2. custom(bubbling)
  3. additionwas added at a rate such as
  4. temperatureto maintain
  5. temperaturea constant reflux (1 hour)
  6. temperatureThe reaction was further refluxed for 1 hour
  7. temperaturebefore cooling in an ice-water bath
  8. temperaturethe reaction was refluxed for 1 hour
  9. customIt was recooled in an ice-water bath
  10. temperatureAfter warming up to room temperature
  11. stirringshaking vigorously
  12. customthe phases were separated
  13. washThe organic phase was washed with aqueous saturated bicarbonate (250 ml) and water (500 ml)
  14. extractionEach aqueous phase was re-extracted with diethyl ether (250 ml)
  15. dry with materialCombined extracts were dried over anhydrous sodium sulfate
  16. customThe product was purified by column chromatography on silica gel (eluting with heptanes/ethyl acetate 11:1 to 3:1)
  17. distillationfollowed by bulb-to-bulb distillation (110° C./1 mbar)

Sources & evidence

ORD record
ord-53f6f5a7d5d64a79a1a6710f4ca5d541
Source dataset
uspto-grants-2012_05
Patent number
US08178732B2

Reaction notes

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