Benzyl Bromide → HCID 561517, compound

HRID 881890Notes

Reaction equation

HRID 881890 reaction equation
[CH:1]1([C:6]([OH:8])=[O:7])[CH2:5][CH2:4][CH2:3][CH2:2]1.C([O-])([O-])=O.[K+].[K+].[CH2:15](Br)[C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1>CN(C=O)C>[CH2:15]([O:7][C:6]([CH:1]1[CH2:5][CH2:4][CH2:3][CH2:2]1)=[O:8])[C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1

Participants

5

Reactant 3

HCID 7498Benzyl BromideHCID 11430Potassium CarbonateHCID 18840Cyclopentanecarboxylic acid

Product 1

HCID 561517HCID 561517, compound

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To a stirred solution of cyclopentanecarboxylic acid (1.14 g, 10 mmol) in DMF (15 mL) is added K2CO3 (2.07 g, 15 mmol) and benzyl bromide (1.71 g, 10 mmol). The suspension is stirred at room temperature for 18 hours. The mixture is quenched with water and extracted with ethyl acetate. The organic layer is washed with water, brine, dried over MgSO4 and filtered. The solvent is removed under reduced pressure and the residue is purified by flash chromatography (heptane:EtOAc, 10:1) to give cyclopentanecarboxylic acid benzyl ester. Next, to a stirred solution of LDA (4 mmol, 2M in Hexane) in THF (8 mL) at −78° C. is added a solution of cyclopentanecarboxylic acid benzyl ester (817 mg, 4 mmol) in THF (3 mL) dropwise. After the addition, the mixture is stirred at −78° C. for 5 hours then allyl bromide (726 mg, 6 mmol) is added dropwise. The mixture is warmed to room temperature during 4 hours then the reaction mixture is quenched with saturated NaHCO3. Magnesium sulfate (2 g) is added and stirred until all the MgSO4 is dissolved. The mixture is extracted with ethyl acetate and the organic layer is washed with water, brine, dried over MgSO4 and filtered. The solvent is removed under reduced pressure and the residue is purified by flash chromatography (hep:EtOAc, 10:1) to give 1-allyl-cyclopentanecarboxylic acid benzyl ester. Next, Ozone is bubbled through a solution of 1-allyl-cyclopentanecarboxylic acid benzyl ester in methylene chloride (15 mL) for 30 min then PS-triphenolphosphine (300 mg) is added and the mixture is stirred at room temperature for 5 hours. The resin is filtered and solvent is removed under reduced pressure. The residue is purified by flash chromatography (heptane:EtOAc, 10:1) to give 1-(2-oxo-ethyl)-cyclopentanecarboxylic acid benzyl ester MS 247.3 (M+1).

Workup

  1. customThe mixture is quenched with water
  2. extractionextracted with ethyl acetate
  3. washThe organic layer is washed with water, brine
  4. dry with materialdried over MgSO4
  5. filtrationfiltered
  6. customThe solvent is removed under reduced pressure
  7. customthe residue is purified by flash chromatography (heptane:EtOAc, 10:1)

Sources & evidence

ORD record
ord-4c9ad84f476542fe8f211990169de626
Source dataset
uspto-grants-2015_03
Patent number
US08993631B2

Reaction notes

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