反应详情

To a solution of ethyl acetoacetate (64 mL; 504 mmol) in dry DMF (240 mL) under a nitrogen atmosphere was added potassium carbonate (69.6 g; 504 mmol), which has been dried at 120° C. for 12 h before its use. After stirring for 15 minutes at room temperature, ethyl 2-bromovalerate (81.6 mL; 480 mmol) was slowly added under nitrogen and the mixture was vigorously stirred at room temperature for 20 h. The reaction mixture was poured in water (240 mL) and neutralized by adding HCl 2N. The product was extracted with diethyl ether (2×240 mL) and the combined organic layers were dried over magnesium sulphate and concentrated under reduced pressure. The crude yellow oil was purified by distillation under reduced pressure (160° C./6 mbar) to give 61.8 g of the title compound as a colorless liquid (HPLC purity 60%). ESI/APCI(+): 259 (M+H);

1. customhas been dried at 120° C. for 12 h before its use
2. stirringthe mixture was vigorously stirred at room temperature for 20 h
3. extractionThe product was extracted with diethyl ether (2×240 mL)
4. dry with materialthe combined organic layers were dried over magnesium sulphate
5. concentrationconcentrated under reduced pressure
6. distillationThe crude yellow oil was purified by distillation under reduced pressure (160° C./6 mbar)