1,6-Dibromohexane → HCID 18921940, compound

HRID 1289612Notes

Reaction equation

HRID 1289612 reaction equation
CC(C)(C)C#C.C([Li])CCC.BrCCCCCCBr.[CH3:20][C:21]([CH3:31])([CH3:30])[C:22]#[C:23][CH2:24][CH2:25][CH2:26][CH2:27][CH2:28][CH3:29].[NH:32]1[CH:36]=[CH:35][N:34]=[CH:33]1.[Na]>CN(C=O)C.CS(C)=O.C1COCC1>[CH3:20][C:21]([CH3:30])([CH3:31])[C:22]#[C:23][CH2:24][CH2:25][CH2:26][CH2:27][CH2:28][CH2:29][N:32]1[CH:36]=[CH:35][N:34]=[CH:33]1

Participants

9

Reactant 5

HCID 123681,6-Dibromohexane2×HCID 135123,3-Dimethyl-1-butyneHCID 12625810HCID 12625810, compoundHCID 57373095Imidazole sodiumHCID 178418339Butyllithium

Product 1

HCID 18921940HCID 18921940, compound

Reagents, catalysts & solvents 3

HCID 679Dimethyl SulfoxideSolventHCID 6228DimethylformamideSolventHCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
-78 °C

Procedure

Add 5 ml. freshly distilled THF and 413 mg. 3,3-dimethyl-1-butyne to a dry reaction flask, cool to -78° C. then add 2.01 ml. n-butyl lithium (2.5M in hexane), stir about 30 minutes at -78° C., transfer into 3 ml. THF and 4.9 gm. 1,6-dibromo hexane at 0° C., stir 6 hours and add 2 ml. dry DMSO to form a precipitate. Wash with water, in methylene chloride. Elute through a short bed of silica with hexane to remove polar material giving a mixture of 1,6-dibromo hexane and 1 bromo-(9,9-dimethyl-dec-7-yne. (b) Stir overnight at room temperature 4.73 gm. of the mixture prepared in step (a), 5 ml. DMF and 2.1 gm. sodium imidazole, in a reaction flask. Add methylene chloride, wash with water, then brine and dry over sodium sulfate. Elute on a coarse silica column with methylene chloride, then 2% methanol/methylene chloride. Combine fractions containing product and chromatograph on a coarse silica column with 25% ethylacetate/methylene chloride, then 35% ethylacetate/ methylene chloride to isolate the title compound.

Workup

  1. additionAdd 5 ml
  2. additionthen add 2.01 ml
  3. additionadd 2 ml
  4. washWash with water, in methylene chloride
  5. washElute through a short bed of silica with hexane
  6. customto remove polar material
  7. customgiving
  8. washAdd methylene chloride, wash with water
  9. dry with materialbrine and dry over sodium sulfate
  10. washElute on a coarse silica column with methylene chloride
  11. additionCombine fractions containing product and chromatograph on a coarse silica column with 25% ethylacetate/methylene chloride

Sources & evidence

ORD record
ord-0d75e9c4d80a4fdb97a7cb42ebbc5008
Source dataset
uspto-grants-1998_05
Patent number
US05750532

Reaction notes

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