Potassium Carbonate → Ethyl 4-oxobutanoate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of 4-[4-(3-chloro-propoxy)-phenyl]-3-methyl-4-oxo-butyric acid ethyl ester (7 g, 22 mmol), K2CO3 (9.3 g, 67 mmol), Nat (330 mg, 2.2 mmol), and (R)-methyl-pyrrolidinium benzenesulfonate (11 g, 47 mmol) in CH3CN (160 mL) was heated under argon at 80° C. for 36 h. The reaction mixture was concentrated at reduced pressure and partitioned between saturated aqueous sodium bicarbonate solution and methylene chloride. The aqueous layer was extracted twice with methylene chloride and the combined organics was washed with brine, dried (Na2SO4), filtered, and concentrated to provide a crude material. The crude material was purified by ISCO (80 g siliga gel column) chromatography using 2% to 9% methanol in methylene chloride to 10% methanol containing 2.5 mL ammonium hydroxide in methylene chloride to afford a pure product. The pure product was dissolved in methylene chloride and washed with saturated aqueous sodium bicarbonate solution, brine, dried (Na2SO4), filtered, and concentrated to give 3-methyl-4-{4-R-2-methyl-pyrrolidin-1-yl)-propoxy]-phenyl}-4-oxo-butyric acid ethyl ester (8.39 g, quantitative yield), MS m/z 362 (M+H).

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