Phosphorus pentachloride → Methyl 3-chloro-2,2-dimethylbut-3-enoate

HRID 1991730Notes

Reaction equation

HRID 1991730 reaction equation
P(Cl)(Cl)(Cl)(Cl)[Cl:2].[CH3:7][C:8]([CH3:16])([C:13](=O)[CH3:14])[C:9]([O:11][CH3:12])=[O:10]>C(Cl)Cl.CN(C=O)C>[Cl:2][C:13](=[CH2:14])[C:8]([CH3:16])([CH3:7])[C:9]([O:11][CH3:12])=[O:10]

Participants

5

Reactant 2

HCID 24819Phosphorus pentachlorideHCID 96925Methyl 2,2-dimethylacetoacetate

Product 1

HCID 40423475Methyl 3-chloro-2,2-dimethylbut-3-enoateYield 38.6%

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideCatalystHCID 6344DichloromethaneSolvent

Procedure

To a suspension of PCl5 (270 g, 1.3 mol) in CH2Cl2 (1000 mL) was added dropwise methyl 2,2-dimethyl-3-oxobutanoate (85 g) at 0° C., following by addition of approximately 30 drops of dry DMF. The mixture was heated at reflux overnight. The reaction mixture was cooled to ambient temperature and slowly poured into ice water. The organic layer was separated and the aqueous phase was extracted with CH2Cl2 (500 mL×3). The combined organic layers were washed with saturated aqueous NaHCO3 and dried over anhydrous Na2SO4. The solvent was evaporated and the residue was distilled under reduced pressure to give methyl 3-chloro-2,2-dimethylbut-3-enoate (37 g, 23%). 1H NMR (400 MHz, CDCl3) δ 5.33 (s, 1H), 3.73 (s, 3H), 1.44 (s, 6H).

Workup

  1. temperatureThe mixture was heated
  2. temperatureat reflux overnight
  3. customThe organic layer was separated
  4. extractionthe aqueous phase was extracted with CH2Cl2 (500 mL×3)
  5. washThe combined organic layers were washed with saturated aqueous NaHCO3
  6. dry with materialdried over anhydrous Na2SO4
  7. customThe solvent was evaporated
  8. distillationthe residue was distilled under reduced pressure

Sources & evidence

ORD record
ord-b57724ba30e54d23aa6b91397dd07794
Source dataset
uspto-grants-2010_01
Patent number
US07645789B2

Reaction notes

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