Diethyl methylmalonate → Diethyl 2-methyl-2-(pent-4-ynyl)malonate

HRID 1197362

Reaction equation

HRID 1197362 reaction equation
[CH3:1][CH:2]([C:8]([O:10][CH2:11][CH3:12])=[O:9])[C:3]([O:5][CH2:6][CH3:7])=[O:4].[H-].[Na+].CS(O[CH2:20][CH2:21][CH2:22][C:23]#[CH:24])(=O)=O>O1CCCC1>[CH3:1][C:2]([CH2:24][CH2:23][CH2:22][C:21]#[CH:20])([C:3]([O:5][CH2:6][CH3:7])=[O:4])[C:8]([O:10][CH2:11][CH3:12])=[O:9]

Participants

5

Reactant 3

HCID 11857Diethyl methylmalonateHCID 24758Sodium hydrideHCID 12476209Pent-4-yn-1-yl methanesulfonate

Product 1

HCID 19373418Diethyl 2-methyl-2-(pent-4-ynyl)malonate

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent3×

Procedure

A solution of diethyl methylmalonate (Aldrich Chemical Company, 35.6 ml) in dry tetrahydrofuran (200 ml) was added, dropwise, to a stirred suspension of sodium hydride (60% dispersion in mineral oil, 9.1 g) in tetrahydrofuran (50 ml) under nitrogen. After the addition was complete, the mixture was heated to gentle reflux for 1 hour and then allowed to cool before a solution of pent-4-ynyl methanesulphonate (35.2 g) in tetrahydrofuran (50 ml) was added. The resulting mixture was heated to gentle reflux for a further 2 hours. The bulk of the solvent was then removed in vacuo and the residue was partitioned between diethyl ether and water. The organic phase was separated and washed with water and brine before drying over anhydrous magnesium sulphate and evaporation under reduced pressure. Distillation gave diethyl 2-methyl-2-(pent-4-ynyl)malonate (45.8 g) as a colourless oil (b.p. 92°-97°, 0.5 mm Hg).

Workup

  1. additionAfter the addition
  2. temperaturethe mixture was heated
  3. temperatureto gentle reflux for 1 hour
  4. additionwas added
  5. temperatureThe resulting mixture was heated
  6. temperatureto gentle reflux for a further 2 hours
  7. customThe bulk of the solvent was then removed in vacuo
  8. customthe residue was partitioned between diethyl ether and water
  9. customThe organic phase was separated
  10. washwashed with water and brine
  11. dry with materialbefore drying over anhydrous magnesium sulphate and evaporation under reduced pressure
  12. distillationDistillation

Sources & evidence

ORD record
ord-8b26beca42b24cb99a0ab323cdfbbf78
Source dataset
uspto-grants-1992_05
Patent number
US05116862

Linked notes

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