Reaktion #340238

Reaktionsgleichung

4-chlorophenylacetic acid

carbonyldiimidazole

ethyl malonate potassium salt

magnesium chloride

HCl

→

ethyl 4-(4-chlorophenyl)-3-oxobutyrate

Ausbeute 95.3%

Lösungsmittel

acetonitrile

acetonitrile

triethylamine

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeprepared above at room temperature
2. 2
   workup.STIRRINGthe mixture was stirred at the same temperature for 30 minutes and at 80° C. for 2 hours
3. 3
   workup.STIRRINGthe mixture was stirred
4. 4
   WaschenThe organic layer was washed with an aqueous sodium hydrogencarbonate solution
5. 5
   Trocknena brine, dried over magnesium sulfate
6. 6
   Filtrationfiltered
7. 7
   EinengenThe filtrate was concentrated in vacuo
8. 8
   Sonstigethe resultant crude product was purified by column chromatography on silica gel (solvent: hexane/ethyl acetate=8/1 to 6/1)

Vorschrift

To a solution of ethyl malonate potassium salt (39 g) in acetonitrile (100 mL) was added magnesium chloride (26 g) and triethylamine (48.6 g) and the mixture was stirred at room temperature for 2 hours (solution A). To a solution of 4-chlorophenylacetic acid (18.6 g) in acetonitrile (100 mL) was added carbonyldiimidazole (19.5 g) at room temperature and the mixture was stirred at the same temperature fro 1.5 hours. To the reaction mixture was added the solution A prepared above at room temperature and the mixture was stirred at the same temperature for 30 minutes and at 80° C. for 2 hours. After cooling the reaction mixture to room temperature, thereto was added 2N HCl solution (260 mL) and the mixture was stirred. The organic layer was washed with an aqueous sodium hydrogencarbonate solution and a brine, dried over magnesium sulfate and filtered. The filtrate was concentrated in vacuo and the resultant crude product was purified by column chromatography on silica gel (solvent: hexane/ethyl acetate=8/1 to 6/1) to obtain ethyl 4-(4-chlorophenyl)-3-oxobutyrate (25 g, yield: 95%) as a liquid.

Quelle