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

HRID 2107633Notes

Reaction equation

HRID 2107633 reaction equation
[CH:1]1([C:4](=[O:11])[CH2:5][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)C>>[CH:1]1([C:4](=[O:11])[C:5](=[CH:12][O:13][CH2:14][CH3:15])[C:6]([O:8][CH2:9][CH3:10])=[O:7])[CH2:3][CH2:2]1

Participants

4

Reactant 3

HCID 7918Acetic AnhydrideHCID 31214Ethyl orthoformateHCID 262979Ethyl 3-cyclopropyl-3-oxopropanoate

Product 1

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

Procedure

Ethyl β-cyclopropyl-β-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-d3a1d73e4bb7462b9daaebf2ba893fb3
Source dataset
uspto-grants-1990_06
Patent number
US04935434

Reaction notes

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