Trimethylsilylacetylene → 1-Ethynyl-4-pentylbenzene

HRID 1613527Notes

Reaction equation

HRID 1613527 reaction equation
[CH2:1]([C:6]1[CH:11]=[CH:10][C:9](I)=[CH:8][CH:7]=1)[CH2:2][CH2:3][CH2:4][CH3:5].C[Si]([C:17]#[CH:18])(C)C>C(NCC)C.[Cu]I>[CH2:1]([C:6]1[CH:11]=[CH:10][C:9]([C:17]#[CH:18])=[CH:8][CH:7]=1)[CH2:2][CH2:3][CH2:4][CH3:5]

Participants

5

Reactant 2

HCID 66111TrimethylsilylacetyleneHCID 1450574-Iodopentylbenzene

Product 1

HCID 27751311-Ethynyl-4-pentylbenzene

Reagents, catalysts & solvents 2

HCID 24350Copper(1+) iodide; Copper(I) iodide; Cuprous iodide; Cuprous iodide (CuI)CatalystHCID 8021DiethylamineSolvent

Procedure

A mixture of 0.1 mol of 4-pentyliodobenzene, 0.12 mol of trimetylsilylacetylene, 0.0014 mol of bis(triphenylphosphine)-palladium(II) Chloride Pd(PPh3)2Cl2 and 0.7 mmol of copper (I) iodide in 250 ml diethylamine is stirred at room temperature for 20 hours. After evaporation of the solvent the crude product is purified by chromatography on alumina (4:1 petrol/dichloromethane) to give 2-(4-pentylphenyl)-1-trimethylsilyacetylene. Removal of the trimethylsilylgroup is accomplished by treatment this acetylene is methanol with 1 M KOH for 1 hour at room temperature. Evaporation of the methanol and either extraction yields 4-pentylphenylacetylene.

Workup

  1. customAfter evaporation of the solvent the crude product
  2. customis purified by chromatography on alumina (4:1 petrol/dichloromethane)
  3. customto give 2-(4-pentylphenyl)-1-trimethylsilyacetylene
  4. customRemoval of the trimethylsilylgroup
  5. customfor 1 hour
  6. customat room temperature
  7. customEvaporation of the methanol
  8. extractioneither extraction

Sources & evidence

ORD record
ord-8d3750c7882344f3845bdb3d1508da83
Source dataset
uspto-grants-1993_03
Patent number
US05194178

Reaction notes

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