Sulfuric Acid → Ethyl 2,4-dioxoheptanoate

HRID 2371454Notes

Reaction equation

HRID 2371454 reaction equation
[O-]CC.[Na+].[CH3:5][C:6](=[O:10])[CH2:7][CH2:8][CH3:9].[C:11]([O:18][CH2:19][CH3:20])(=[O:17])[C:12]([O:14]CC)=O.S(=O)(=O)(O)O>C(O)C>[O:14]=[C:12]([CH2:5][C:6](=[O:10])[CH2:7][CH2:8][CH3:9])[C:11]([O:18][CH2:19][CH3:20])=[O:17]

Participants

6

Reactant 4

HCID 1118Sulfuric AcidHCID 7268Diethyl OxalateHCID 78952-PentanoneHCID 2723922Sodium ethoxide

Product 1

HCID 3006750Ethyl 2,4-dioxoheptanoateYield 38.1%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

To refluxing solution of sodium ethoxide (51.2 g, 0.75 mmol) in ethanol (170 ml) was added dropwise over 30 minutes a solution of 2-pentanone (59 g, 0.68 mol) in diethyl oxalate (99 g, 0.68 mol). The resulting turbid yellow mixture was refluxed further for 2 hours, cooled to room temperature, poured over 500 g ice with stirring and adjusted to pH 1-2 with concentrated sulfuric acid (~40 ml). The organic phase was extracted with benzene (3×300 ml), washed once with saturated aqueous sodium chloride and dried over anhydrous sodium sulfate, before being filtered, concentrated, and fractionally distilled at 0.1 mm Hg to give 48.2 g (38%) of the title compound as a yellow liquid; b.p. 85°-95° C.

Workup

  1. temperatureThe resulting turbid yellow mixture was refluxed further for 2 hours
  2. extractionThe organic phase was extracted with benzene (3×300 ml)
  3. washwashed once with saturated aqueous sodium chloride
  4. dry with materialdried over anhydrous sodium sulfate
  5. filtrationbefore being filtered
  6. concentrationconcentrated
  7. distillationfractionally distilled at 0.1 mm Hg

Sources & evidence

ORD record
ord-bb6b1e03d65e4dcb8eb8404930b49531
Source dataset
uspto-grants-1992_03
Patent number
US05093346

Reaction notes

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