Reaktion #1590370

Reaktionsgleichung

lithium bis(trimethylsilyl)amide

trimethylphosphonoacetate

4′-(trifluoromethyl)propiophenone

THF

→

3-(4-trifluoromethylphenyl)pent-2-enoic acid methyl ester

Ausbeute 85.0%

Lösungsmittel

NH4Cl

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigethe temperature below 10° C
2. 2
   TemperaturThe solution was slowly heated to 50° C. for eight hours
3. 3
   TemperaturThe solution was cooled to room temperature
4. 4
   Extraktionextracted with ethyl acetate (2×100 mL)
5. 5
   Trocknendried over MgSO4
6. 6
   Filtrationfiltered
7. 7
   Einengenthe filtrate concentrated to a white solid which
8. 8
   Sonstigewas recrystallized from hexane/ethyl acetate

Vorschrift

To a chilled (0° C.) solution of lithium bis(trimethylsilyl)amide (1.0 M, 50 mL) was dropwise added a solution of trimethylphosphonoacetate, keeping the temperature below 10° C. The solution was then allowed to warm to room temperature and stirred for an additional five minutes, after which a solution of 4′-(trifluoromethyl)propiophenone in THF (25 mL) was added in one portion. The solution was slowly heated to 50° C. for eight hours. The solution was cooled to room temperature, then diluted with a 10% NH4Cl solution (100 mL), and extracted with ethyl acetate (2×100 mL). The organic layers were combined and dried over MgSO4, filtered, and the filtrate concentrated to a white solid which was recrystallized from hexane/ethyl acetate to give 5.42 grams of 3-(4-trifluoromethylphenyl)pent-2-enoic acid methyl ester intermediate (85% yield).

Quelle