Dimethylformamide → diazomethyl-(2-(S)-(3,4-dichlorophenyl)-pent-4-en-yl)-ketone

HRID 974878Notes

Reaction equation

HRID 974878 reaction equation
[Cl:1][C:2]1[CH:3]=[C:4]([C@H:9]([CH2:13][CH:14]=[CH2:15])[C:10](O)=O)[CH:5]=[CH:6][C:7]=1[Cl:8].[C:16](Cl)(=[O:20])[C:17](Cl)=O.CN(C)C=O.[N+:27](=C)=[N-:28]>ClCCl.CCOCC>[N+:27](=[CH:17][C:16]([CH2:10][C@@H:9]([C:4]1[CH:5]=[CH:6][C:7]([Cl:8])=[C:2]([Cl:1])[CH:3]=1)[CH2:13][CH:14]=[CH2:15])=[O:20])=[N-:28]

Participants

7

Reactant 4

HCID 6228DimethylformamideHCID 9550DiazomethaneHCID 65578Oxalyl chlorideHCID 15261879(S)-2-(3,4-dichlorophenyl)pent-4-enoic acid

Product 1

HCID 54285560diazomethyl-(2-(S)-(3,4-dichlorophenyl)-pent-4-en-yl)-ketoneYield 84%

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 6344DichloromethaneSolvent

Procedure

To a solution of 2-(S)-(3,4-dichlorophenyl)-pent-4-enoic acid (5.04 g, 20.6 mmol) in 60 mL of dichloromethane was added 2.15 mL (24.6 mmol) of oxalyl chloride and 0.1 mL of dimethylformamide with cooling in an ice-water bath. The cooling bath was then removed and the reaction mixture was stirred at rt overnight. The solvent was removed under reduced pressure, and the resulting material was diluted in ethyl acetate and concentrated in vacuo in order to remove residual HCl. The residual crude acid chloride was dissolved in 70 mL of ether and was slowly added to a 100 mL ether solution of diazomethane (77 mmol). After stirring for 2 hr at rt, the solvent was removed under vacuum. The resulting yellow oil was chromatographed on silica gel column eluting with a gradient of hexane:ethyl acetate=20:1 to 3:1 to give 4.66 g (84%) of diazomethyl-(2-(S)-(3,4-dichlorophenyl)-pent-4-enyl)-ketone.

Workup

  1. temperaturewith cooling in an ice-water bath
  2. customThe cooling bath was then removed
  3. customThe solvent was removed under reduced pressure
  4. additionthe resulting material was diluted in ethyl acetate
  5. concentrationconcentrated in vacuo in order
  6. customto remove residual HCl
  7. dissolutionThe residual crude acid chloride was dissolved in 70 mL of ether
  8. stirringAfter stirring for 2 hr at rt
  9. customthe solvent was removed under vacuum
  10. customThe resulting yellow oil was chromatographed on silica gel column
  11. washeluting with a gradient of hexane

Sources & evidence

ORD record
ord-e17265ec19ca4dcf8df9e7d3f0a52668
Source dataset
uspto-grants-1997_03
Patent number
US05607936

Reaction notes

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