1,4-Dibromobutane → Benzyl 1-(4-bromobutyl)-2-oxo-cyclopentanecarboxylate

HRID 1875299Notes

Reaction equation

HRID 1875299 reaction equation
[H-].[Na+].[O:3]=[C:4]1[CH2:8][CH2:7][CH2:6][CH:5]1[C:9]([O:11][CH2:12][C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1)=[O:10].[Br:19][CH2:20][CH2:21][CH2:22][CH2:23]Br.[Cl-].[NH4+]>C1COCC1.CCOCC.CN(P(N(C)C)(N(C)C)=O)C>[Br:19][CH2:20][CH2:21][CH2:22][CH2:23][C:5]1([C:9]([O:11][CH2:12][C:13]2[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=2)=[O:10])[CH2:6][CH2:7][CH2:8][C:4]1=[O:3]

Participants

8

Reactant 4

HCID 80561,4-DibromobutaneHCID 24758Sodium hydrideHCID 25517Ammonium ChlorideHCID 9794427Benzyl 2-oxocyclopentane-1-carboxylate

Product 1

HCID 68781908Benzyl 1-(4-bromobutyl)-2-oxo-cyclopentanecarboxylate

Reagents, catalysts & solvents 3

HCID 3283Diethyl EtherSolventHCID 8028TetrahydrofuranSolvent2×HCID 12679HexamethylphosphoramideSolvent

Procedure

In a 500 mL three-necked flask provided with magnetic stirring and a condenser, under an inert nitrogen atmosphere, sodium hydride 95% (2.2 g; 87.1 mmol; 1.25 eq.) is suspended in a mixture of anhydrous THF (115 mL) and HMPA (14.6 mL). A solution of benzyl 2-oxocyclopentanecarboxylate (15.3 g; 70.3 mmol) in 45 mL of anhydrous THF is added dropwise so as to keep the temperature below 45° C. The reaction mixture is stirred for 1 hour at ambient temperature. 1,4-Dibromobutane (12.6 mL; 105.4 mmol; 1.5 eq.) is added to the clear yellow solution. The reaction mixture is stirred again, for 14 hours, at reflux. After coming back to ambient temperature, 80 mL of saturated aqueous ammonium chloride solution are added. The mixture is poured into 500 mL of ether and the organic phase is washed five times with 100 mL of water and then with 100 mL of saturated aqueous sodium chloride solution. The organic phase is dried over MgSO4, filtered and concentrated.

Workup

  1. customIn a 500 mL three-necked flask provided
  2. customthe temperature below 45° C
  3. stirringThe reaction mixture is stirred for 1 hour at ambient temperature
  4. stirringThe reaction mixture is stirred again, for 14 hours
  5. temperatureat reflux
  6. customAfter coming back to ambient temperature
  7. washthe organic phase is washed five times with 100 mL of water
  8. dry with materialThe organic phase is dried over MgSO4
  9. filtrationfiltered
  10. concentrationconcentrated

Sources & evidence

ORD record
ord-a6f4d74de9794138b8574fc0a8f97cc7
Source dataset
uspto-grants-2012_11
Patent number
US08309341B2

Reaction notes

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