2-Oxime 2,3-butanedione → HCID 23076475, compound

HRID 2221589Notes

Reaction equation

HRID 2221589 reaction equation
[CH:1]([C:3]1[O:7][C:6]([C:8]([O:10][CH2:11][CH3:12])=[O:9])=[CH:5][CH:4]=1)=[O:2].[CH3:13][C:14](=[N:18]O)[C:15](=O)[CH3:16].[ClH:20].C(OCC)(=O)C>C(OCC)C>[Cl:20][CH2:13][C:14]1[N:18]=[C:1]([C:3]2[O:7][C:6]([C:8]([O:10][CH2:11][CH3:12])=[O:9])=[CH:5][CH:4]=2)[O:2][C:15]=1[CH3:16]

Participants

5

Reactant 3

HCID 63989692-Oxime 2,3-butanedioneHCID 15589950Ethyl 5-formylfuran-2-carboxylateHCID 21866389Hydrogen chloride-ethyl acetate

Product 1

HCID 23076475HCID 23076475, compoundYield 30%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Procedure

A mixture of ethyl 5-formyl-2-furancarboxylate (5.33 g), 2,3-butanedione-2-oxime (3.21 g) and 4N hydrogenchloride-ethyl acetate solution (100 mL) was stirred at room temperature for 3 days. After concentration of the reaction mixture, diethyl ether was added to the residue and the precipitated crystals were collected by filtration. A mixture of the obtained crystal, tetrahydrofuran (100 mL) and thionyl chloride (5.66 g) was heated under reflux for 3 hrs. The reaction mixture was concentrated and ethyl acetate was added to the residue. The ethyl acetate layer was washed successively with saturated aqueous sodium hydrogen carbonate solution and saturated brine, dried over anhydrous magnesium sulfate and concentrated. The residue was subjected to silica gel column chromatography to give ethyl 5-(4-chloromethyl-5-methyl-1,3-oxazol-2-yl)-2-furancarboxylate as colorless crystals (2.60 g, yield 30%) from a fraction eluted with ethyl acetate-hexane (1:4, v/v). Recrystallization from ethyl acetate-hexane gave colorless prism crystals. melting point: 117-118° C.

Workup

  1. filtrationthe precipitated crystals were collected by filtration
  2. additionA mixture of the obtained crystal, tetrahydrofuran (100 mL) and thionyl chloride (5.66 g)
  3. temperaturewas heated
  4. temperatureunder reflux for 3 hrs
  5. concentrationThe reaction mixture was concentrated
  6. additionethyl acetate was added to the residue
  7. washThe ethyl acetate layer was washed successively with saturated aqueous sodium hydrogen carbonate solution and saturated brine
  8. dry with materialdried over anhydrous magnesium sulfate
  9. concentrationconcentrated

Sources & evidence

ORD record
ord-20801aece3ab469da59433dc58dc0948
Source dataset
uspto-grants-2008_05
Patent number
US07368578B2

Reaction notes

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