Reaktion #158355

Reaktionsgleichung

Lawesson's reagent

ethyl (3R)-2-oxo-3-(3,4,5-trifluorophenoxy)piperidine-3-carboxylate

→

ethyl (3S)-2-thioxo-3-(3,4,5-trifluorophenoxy)piperidine-3-carboxylate

Ausbeute 142.8%

Lösungsmittel

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturAfter cooling to room temperature
2. 2
   Sonstigethe reaction mixture was purified by silica gel column chromatography (NH, ethyl acetate/hexane)

Vorschrift

Lawesson's reagent (4.46 g) was added to a mixture of ethyl (3R)-2-oxo-3-(3,4,5-trifluorophenoxy)piperidine-3-carboxylate (5.00 g) in toluene (50 mL) at room temperature, and the mixture was stirred with heating at 100° C. for 1 hr. After cooling to room temperature, the reaction mixture was purified by silica gel column chromatography (NH, ethyl acetate/hexane) to give ethyl (3S)-2-thioxo-3-(3,4,5-trifluorophenoxy)piperidine-3-carboxylate (5.25 g). To a mixture of ethyl (3S)-2-thioxo-3-(3,4,5-trifluorophenoxy)piperidine-3-carboxylate (5.25 g) in acetonitrile (25 mL) was added methyl iodide (2.94 mL) at room temperature, and the mixture was stirred under a nitrogen atmosphere at 50° C. for 1 hr. The reaction mixture was concentrated under reduced pressure, to the residue was added 10% aqueous potassium carbonate solution, and the mixture was extracted with ethyl acetate. The extract was washed with saturated brine, dried over anhydrous sodium sulfate, and purified by silica gel column chromatography (NH, ethyl acetate) to give the title compound (5.65 g).

Quelle