Diethyl Ether → Diethyl 2-pent-4-enylpropanedioate

HRID 2254980Notes

Reaction equation

HRID 2254980 reaction equation
[Na].Br[CH2:3][CH2:4][CH2:5][CH:6]=[CH2:7].C(OCC)C.[Cl-].[Na+].[C:15]([O:23][CH2:24][CH3:25])(=[O:22])[CH2:16][C:17]([O:19][CH2:20][CH3:21])=[O:18]>C(O)C>[CH2:3]([CH:16]([C:17]([O:19][CH2:20][CH3:21])=[O:18])[C:15]([O:23][CH2:24][CH3:25])=[O:22])[CH2:4][CH2:5][CH:6]=[CH2:7]

Participants

7

Reactant 5

HCID 3283Diethyl EtherHCID 5234Sodium ChlorideHCID 7761Diethyl MalonateHCID 707041-Pentene, 5-bromo-HCID 5360545Sodium

Product 1

HCID 361718Diethyl 2-pent-4-enylpropanedioateYield 47.5%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

7.05 g of sodium were dissolved in a solution of 49 g of diethyl malonate in 175 ml of ethanol. The still warm solution (50° C.) was treated dropwise within 15 minutes with 45.6 g of 5-bromo-1-pentene and the mixture was heated to boiling for 2 hours. After cooling the reaction mixture was poured into 500 ml of diethyl ether and 300 ml of semi-saturated sodium chloride solution. The aqueous phase was separated and back-extracted twice with 200 ml of diethyl ether each time. The organic phases were washed twice with 150 ml of semi-saturated sodium chloride solution each time, dried over sodium sulphate, filtered and concentrated. Chromatographic separation of the resulting, yellow liquid (55.2 g) on silica gel with hexane/ethyl acetate (vol. 95:5) gave 33.2 g of diethyl (4-pentenyl)-malonate as a colourless liquid.

Workup

  1. temperaturethe mixture was heated
  2. temperatureAfter cooling the reaction mixture
  3. customThe aqueous phase was separated
  4. extractionback-extracted twice with 200 ml of diethyl ether each time
  5. washThe organic phases were washed twice with 150 ml of semi-saturated sodium chloride solution each time
  6. dry with materialdried over sodium sulphate
  7. filtrationfiltered
  8. concentrationconcentrated
  9. customChromatographic separation of the resulting, yellow liquid (55.2 g) on silica gel with hexane/ethyl acetate (vol. 95:5)

Sources & evidence

ORD record
ord-5e2eababb27445dfbae396a7451cc5bb
Source dataset
uspto-grants-1993_08
Patent number
US05238602

Reaction notes

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