5-Methyl-2-hexanone → 3-Chloro-2-isobutyl-but-2-enal

HRID 1676102Notes

Reaction equation

HRID 1676102 reaction equation
P(Cl)(Cl)([Cl:3])=O.[CH3:6][CH:7]([CH3:13])[CH2:8][CH2:9][C:10](=[O:12])C.[CH3:14][C:15]([O-])=O.[Na+]>CN(C=O)C>[Cl:3][C:15]([CH3:14])=[C:9]([CH2:8][CH:7]([CH3:6])[CH3:13])[CH:10]=[O:12]

Participants

5

Reactant 3

HCID 80345-Methyl-2-hexanoneHCID 24813Phosphorus oxychlorideHCID 517045Sodium Acetate

Product 1

HCID 866457643-Chloro-2-isobutyl-but-2-enalYield 125.9%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
5 °C

Procedure

Phosphorusoxychloride (53.7 g, 350 mmol) is slowly added to DMF (60 mL) stirred at 5° C. Upon complete addition, the clear solution is stirred for further 30 min at 5° C. before 5-methyl-2-hexanone (20 g, 175 mmol) is added dropwise. The yellow solution is stirred for 30 min at 0° C., then for 90 min at rt. The mixture becomes warm (40° C.) and a thick suspension forms. The mixture is cooled to 25° C. and stirring is continued for 1 h before it is poured into an aq. solution of NaOAc (80 g)/ice mixture. The mixture is extracted twice with diethyl ether. The organic extracts are washed with water, combined, dried over MgSO4, filtered and evaporated to give crude 3-chloro-2-isobutyl-but-2-enal (35.4 g) as a yellow oil, LC-MS: tR=0.97 min.

Workup

  1. additionUpon complete addition
  2. additionis added dropwise
  3. stirringThe yellow solution is stirred for 30 min at 0° C.
  4. temperatureThe mixture becomes warm (40° C.)
  5. temperatureThe mixture is cooled to 25° C.
  6. stirringstirring
  7. waitis continued for 1 h before it
  8. extractionThe mixture is extracted twice with diethyl ether
  9. washThe organic extracts are washed with water
  10. dry with materialdried over MgSO4
  11. filtrationfiltered
  12. customevaporated

Sources & evidence

ORD record
ord-0c9bccf4b12b414da79762c9ba2603e2
Source dataset
uspto-grants-2011_08
Patent number
US08003800B2

Reaction notes

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