Acetic Anhydride → Ethyl beta-cyclopropyl-alpha-ethoxymethylene-beta-ketopropionate

HRID 477497Notes

Reaction equation

HRID 477497 reaction equation
[CH:1]1([CH2:4][C:5](=O)[C:6]([O:8][CH2:9][CH3:10])=[O:7])[CH2:3][CH2:2]1.[CH:12](OCC)(OCC)[O:13][CH2:14][CH3:15].C(OC(=O)C)(=[O:24])C>>[CH:1]1([C:4](=[O:24])[C:5](=[CH:12][O:13][CH2:14][CH3:15])[C:6]([O:8][CH2:9][CH3:10])=[O:7])[CH2:2][CH2:3]1

Participants

4

Reactant 3

HCID 7918Acetic AnhydrideHCID 31214Ethyl orthoformateHCID 22285629Ethyl 3-cyclopropyl-2-oxopropanoate

Product 1

HCID 57004106Ethyl beta-cyclopropyl-alpha-ethoxymethylene-beta-ketopropionateYield 96%

Procedure

Ethyl β-cyclopropyl-α-ketopropionate (247.0 g, 1.58 mole) [prepared according to the procedure described in J. Am. Chem. Soc., 70 , 497 (1948)], triethyl orthoformate (468.3 g, 3.16 mole) and acetic anhydride (484.0 g, 4.74 mole) were combined and the solution was stirred at reflux for 4 h and at ambient temperature for 17 h. The excess reagents were distilled at water aspirator pressure (maximum head temperature permitted was 72° C.) and the oily pot residue was stirred at 10° C. with a mixture of ether and water. The ether layer was separated, washed once with cold water and dried over Na2SO4. Removal of the solvent gave 321.5 g (96%) of an orange-red liquid that was used directly in the next step.

Workup

  1. distillationThe excess reagents were distilled at water aspirator pressure (maximum head temperature permitted was 72° C.)
  2. stirringthe oily pot residue was stirred at 10° C. with a mixture of ether and water
  3. customThe ether layer was separated
  4. washwashed once with cold water
  5. dry with materialdried over Na2SO4
  6. customRemoval of the solvent

Sources & evidence

ORD record
ord-a0d39fae3c504fb89f5e8a2ba069a86e
Source dataset
uspto-grants-1989_12
Patent number
US04888357

Reaction notes

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