Reaktion #45908

Reaktionsgleichung

tert-butyl (3S)-3-methyl-5-oxo-1-[(1R)-1-phenylethyl]pyrrolidine-3-carboxylate

trifluoroacetic acid

triethylamine

diphenylphosphorylazide

tert-Butanol

→

compound

Ausbeute 60.0%

tert-Butyl {(3S)-3-methyl-5-oxo-1-[(1R)-1-phenylethyl]pyrrolidin-3-yl}carbamate

Ausbeute 60.0%

Lösungsmittel

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe reaction liquid
2. 2
   Einengenwas concentrated under reduced pressure
3. 3
   workup.DISSOLUTIONdissolved in chloroform
4. 4
   Waschenwashed with saturated brine (60 ml)
5. 5
   TrocknenAfter drying over anhydrous sodium sulfate and concentration under reduced pressure
6. 6
   workup.DISSOLUTIONthe resulting residue was dissolved in toluene (20 ml)
7. 7
   workup.STIRRINGby stirring at room temperature for 30 minutes
8. 8
   workup.STIRRINGby stirring in an oil bath at 125° C. for 3 hours
9. 9
   workup.STIRRINGby stirring in an oil bath at 100° C. for 11 hours
10. 10
    SonstigeThe reaction liquid
11. 11
    Einengenwas concentrated under reduced pressure
12. 12
    workup.DISSOLUTIONthe residue was dissolved in ethyl acetate
13. 13
    Waschenwashed with saturated brine
14. 14
    TrocknenAfter drying over anhydrous sodium sulfate and concentration
15. 15
    Sonstigethe resulting residue was purified by silica gel column chromatography (eluent, n-hexane:ethyl acetate=2:1→1:4, v/v)

Vorschrift

With cooling with ice, trifluoroacetic acid (7 ml) was added to a dichloromethane (14 ml) solution of tert-butyl (3S)-3-methyl-5-oxo-1-[(1R)-1-phenylethyl]pyrrolidine-3-carboxylate (I-342) (800 mg, 2.64 mmol), followed by stirring at room temperature for 13 hours. The reaction liquid was concentrated under reduced pressure, dissolved in chloroform, washed with saturated brine (60 ml). After drying over anhydrous sodium sulfate and concentration under reduced pressure, the resulting residue was dissolved in toluene (20 ml), then triethylamine (735 μl, 5.27 mmol) and diphenylphosphorylazide (739 μl, 3.43 mmol) were added, followed by stirring at room temperature for 30 minutes, then by stirring in an oil bath at 125° C. for 3 hours. tert-Butanol (20 ml) was added to the reaction liquid, followed by stirring in an oil bath at 100° C. for 11 hours. The reaction liquid was concentrated under reduced pressure, the residue was dissolved in ethyl acetate, washed with saturated brine. After drying over anhydrous sodium sulfate and concentration, the resulting residue was purified by silica gel column chromatography (eluent, n-hexane:ethyl acetate=2:1→1:4, v/v) to obtain the entitled compound (500 mg, 60%) as a colorless oily substance.

Quelle