Diethyl Oxalate → ethyl 2-oxo-2-(2-oxocyclopentyl)acetate

HRID 2053947Notes

Reaction equation

HRID 2053947 reaction equation
[C:1]1(=[O:6])[CH2:5][CH2:4][CH2:3][CH2:2]1.[C:7](OCC)(=[O:13])[C:8]([O:10][CH2:11][CH3:12])=[O:9].[H-].[Na+]>O1CCCC1>[O:13]=[C:7]([CH:2]1[CH2:3][CH2:4][CH2:5][C:1]1=[O:6])[C:8]([O:10][CH2:11][CH3:12])=[O:9]

Participants

5

Reactant 3

HCID 7268Diethyl OxalateHCID 8452CyclopentanoneHCID 24758Sodium hydride

Product 1

HCID 252487ethyl 2-oxo-2-(2-oxocyclopentyl)acetate

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
0 °C

Procedure

A solution of 15.5 mL (0.175 mol) of cyclopentanone and 23.8 mL (0.175 mol) of diethyl oxalate in 90 mL of tetrahydrofuran are added dropwise at 0° C. to a suspension of 7.0 g (0.175 mol) of sodium hydride (50% in oil) in 60 mL of tetrahydrofuran. The mixture is stirred for another 10 minutes at 0° C. and then heated to ambient temperature. After 5 hours, an exothermic reaction sets in and the mixture heats up to 50° C. After 16 hours, it is combined with ice water and extracted with ether. The aqueous phase is adjusted to pH 4 with glacial acetic acid and extracted with ethyl acetate, dried and concentrated by evaporation. The residue is distilled in vacuo. BP(23 mbar)=135° C.-141° C. Yield: 19.6 g (61%).

Workup

  1. temperatureheated to ambient temperature
  2. waitAfter 5 hours
  3. customan exothermic reaction sets in and the mixture
  4. customheats up to 50° C
  5. waitAfter 16 hours
  6. extractionextracted with ether
  7. extractionextracted with ethyl acetate
  8. customdried
  9. concentrationconcentrated by evaporation
  10. distillationThe residue is distilled in vacuo
  11. customBP(23 mbar)=135° C.-141° C

Sources & evidence

ORD record
ord-efd20165feec4afeb89e2cb06dc80392
Source dataset
uspto-grants-2008_02
Patent number
US07326791B2

Reaction notes

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