Diethyl Oxalate → Ethyl 2,4-dichlorobenzoylformate

HRID 322840

反応式

HRID 322840 の反応式
[Mg].[Cl:2][C:3]1[CH:8]=[CH:7][C:6](I)=[C:5]([Cl:10])[CH:4]=1.[CH2:11]([O:13][C:14](=[O:20])[C:15](OCC)=[O:16])[CH3:12].[NH4+].[Cl-]>C(OCC)C.C(Br)C>[CH2:11]([O:13][C:14](=[O:20])[C:15]([C:6]1[CH:7]=[CH:8][C:3]([Cl:2])=[CH:4][C:5]=1[Cl:10])=[O:16])[CH3:12]

参加物

7

反応物 4

HCID 7268Diethyl OxalateHCID 25517Ammonium ChlorideHCID 968642,4-Dichloro-1-iodobenzeneHCID 5462224Magnesium

生成物 1

HCID 2736411Ethyl 2,4-dichlorobenzoylformate収率 80.1%

試薬・触媒・溶媒 2

HCID 6332Ethyl Bromide触媒2 回HCID 3283Diethyl Ether溶媒3 回

反応条件

温度
-70 °C

実験手順

A suspension of magnesium (6.7 g; 0.275 moles) in ethyl ether (125 ml) under stirring and nitrogen flow was added with ethyl bromide (180 mg). A solution of 1,3-dichloro-4-iodobenzene (50 g; 0.183 moles) and ethyl bromide (180 mg) in ethyl ether (100 ml) was dropped in about 1 hour keeping the temperature at 15-20° C. The suspension was stirred for further 2 hours. After decanting the magnesium in excess, the solution was dropped in about 1 hour in a solution of diethyloxalate (29.32 g; 0.2 moles) in ethyl ether (125 ml) cooled to −70° C. At the end of the addition it was stirred at −70° C. for 1 hour, then the temperature was left to rise to 10° C. and the stirring was kept on for another hour. The suspension was added with a saturated solution of NH4Cl (125 ml), the phases were separated and the aqueous one extracted with ethyl acetate (50 ml). The organic phases were washed with a solution of sodium bisulfite and treated with discolouring charcoal. After filtration, the organic solution was distilled under vacuum to give a crude which was purified by chromatography (SiO2; hexane/ethyl ether 9/1) to give 36.2 g of (2,4-dichloro-phenyl)-oxo-acetic acid ethyl ester (yield 80%) as a colourless oil.

後処理

  1. customat 15-20° C
  2. stirringThe suspension was stirred for further 2 hours
  3. customAfter decanting the magnesium in excess, the solution
  4. additionAt the end of the addition it
  5. stirringwas stirred at −70° C. for 1 hour
  6. waitthe temperature was left
  7. customto rise to 10° C.
  8. customthe phases were separated
  9. extractionthe aqueous one extracted with ethyl acetate (50 ml)
  10. washThe organic phases were washed with a solution of sodium bisulfite
  11. additiontreated with discolouring charcoal
  12. filtrationAfter filtration
  13. distillationthe organic solution was distilled under vacuum
  14. customto give a crude which
  15. customwas purified by chromatography (SiO2; hexane/ethyl ether 9/1)

出典と根拠

ORDレコード
ord-499cf529e7db4cc6b9a7c6b8dfd7cdff
出典データセット
uspto-grants-2001_04
特許番号
US06211387B1

関連ノート

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