Diethyl Malonate → Ethyl pivaloylacetate

HRID 542328Notes

Reaction equation

HRID 542328 reaction equation
[C:1]([O:9][CH2:10][CH3:11])(=[O:8])[CH2:2][C:3]([O:5]CC)=O.[O-]CC.[Na+].[Na].[C:17](Cl)(=O)[C:18](C)([CH3:20])[CH3:19]>C1(C)C(C)=CC=CC=1.C(O)C>[C:3]([CH2:2][C:1]([O:9][CH2:10][CH3:11])=[O:8])(=[O:5])[C:18]([CH3:20])([CH3:19])[CH3:17]

Participants

7

Reactant 4

HCID 7761Diethyl Malonate2×HCID 62493Pivaloyl chlorideHCID 2723922Sodium ethoxideHCID 5360545Sodium2×

Product 1

HCID 86950Ethyl pivaloylacetate

Reagents, catalysts & solvents 2

HCID 702EthanolSolvent2×HCID 7237O-XyleneSolvent

Procedure

Ethyl pivaloylacetate was prepared from diethyl malonate in the following manner. Diethyl malonate (64 g, 0.4 mol) was dissolved in 350 ml of a mixture of xylene isomers. A solution of sodium ethoxide, prepared by dissolving sodium (9.66 g, 0.42 g at) in absolute ethanol (150 ml), was then added with stirring at ambient temperature. Ethanol was removed by distillation. After the mixture was cooled to 50° C., pivaloylchloride (53 g, 0.4 mol) was added with stirring over a period of one hour and the resulting slurry stirred for a further hour. The mixture obtained was then filtered to remove sodium chloride and the filtrate added to dry sodium ethoxide, which had been prepared by dissolving sodium (9.29 g; 0.4 g at) in 250 ml of absolute ethanol and evaporating to dryness. After stirring for 90 minutes at 50° C., the mixture was acidified with dilute hydrochloric acid and the organic phase separated and dried over anhydrous magnesium sulphate. Evaporation of the solvent in a rotary evaporator followed by vacuum distillation afforded essentially pure ethyl pivaloylacetate product as a colorless liquid (b.p. 167° C. at 65 mbar). Structure of the product was confirmed with NMR analysis. The product yield, determined by GLC, was 0.343 mol (86%).

Workup

  1. additionwas then added
  2. customEthanol was removed by distillation
  3. temperatureAfter the mixture was cooled to 50° C.
  4. stirringwith stirring over a period of one hour
  5. stirringthe resulting slurry stirred for a further hour
  6. customThe mixture obtained
  7. filtrationwas then filtered
  8. customto remove sodium chloride
  9. additionthe filtrate added to dry sodium ethoxide, which
  10. customhad been prepared
  11. customevaporating to dryness
  12. stirringAfter stirring for 90 minutes at 50° C.
  13. customthe organic phase separated
  14. dry with materialdried over anhydrous magnesium sulphate
  15. customEvaporation of the solvent
  16. customin a rotary evaporator
  17. distillationfollowed by vacuum distillation

Sources & evidence

ORD record
ord-4f93abc586014ec899354bd3eea346e2
Source dataset
uspto-grants-1987_04
Patent number
US04656309

Reaction notes

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