Dimethylformamide → 1,2-Dimethyl 4-oxo-2-cyclopentene-1,2-dicarboxylate

HRID 1429189Notes

Reaction equation

HRID 1429189 reaction equation
[CH3:1][O:2][C:3]([C@@H:5]1[CH2:9][C:8](=[O:10])[CH2:7][C@@H:6]1[C:11]([O:13][CH3:14])=[O:12])=[O:4].C([O-])([O-])=O.[Ca+2].CN(C=O)C>C1COCC1>[CH3:14][O:13][C:11]([CH:6]1[CH2:7][C:8](=[O:10])[CH:9]=[C:5]1[C:3]([O:2][CH3:1])=[O:4])=[O:12]

Participants

5

Reactant 3

HCID 6228DimethylformamideHCID 10112Calcium CarbonateHCID 108996331,2-dimethyl (1R,2S)-4-oxocyclopentane-1,2-dicarboxylate

Product 1

HCID 591654631,2-Dimethyl 4-oxo-2-cyclopentene-1,2-dicarboxylateYield 45%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
90 °C

Procedure

(1R,2S)-4-oxo-cyclopentane-1,2-dicarboxylic acid dimethyl ester (4.8 g, 23.8 mmol) and CuBr2 (11.9 g, 53.2 mmol) were dissolved in dry THF (70 ml) and the mixture was refluxed for two hours at 90° C. The formed CuBr was filtrated off and the organic phase was concentrated. CaCO3 (2.7 g, 27.2 mmol) and DMF (70 mL) were added and the mixture was held at 100° C. for one hour. The dark brown mixture was poured over ice (35 g) and the formed precipitate was filtrated off. The aqueous layer was extracted with ethyl acetate (1×300 ml+3×150 ml). The organic phases were dried, filtrated and concentrated. Purification by flash chromatography (toluene/EtOAc 9:1) gave the title compound (2.1 g, 45%) as yellow crystals

Workup

  1. filtrationThe formed CuBr was filtrated off
  2. concentrationthe organic phase was concentrated
  3. filtrationthe formed precipitate was filtrated off
  4. extractionThe aqueous layer was extracted with ethyl acetate (1×300 ml+3×150 ml)
  5. customThe organic phases were dried
  6. filtrationfiltrated
  7. concentrationconcentrated
  8. customPurification by flash chromatography (toluene/EtOAc 9:1)

Sources & evidence

ORD record
ord-bbb09f1f7b1d466fbb8647a15e939b01
Source dataset
uspto-grants-2015_01
Patent number
US08937080B2

Reaction notes

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