Reaktion #328745

Reaktionsgleichung

acetic anhydride

tert-butyl 3-oxopyrrolidine-1-carboxylate

sodium bis(trimethylsilyl)amide

→

desired product

tert-Butyl 3-acetyl-4-oxopyrrolidine-1-carboxylate

Lösungsmittel

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGstirred at room temperature for 20 min
2. 2
   SonstigeThe reaction mixture was quenched by the dropwise addition of water
3. 3
   Einengenconcentrated under vacuum
4. 4
   workup.ADDITIONTo the basic residue, ethyl acetate (50 mL) and saturated aqueous sodium bicarbonate solution (30 mL) with an equal volume of water were added
5. 5
   SonstigeThe aqueous layer was separated
6. 6
   workup.ADDITIONacidified by careful addition of hydrochloric acid to pH 3
7. 7
   Extraktionextracted with ethyl acetate (75 mL)
8. 8
   WaschenThe organic layer was washed with brine
9. 9
   Trocknendried over anhydrous sodium sulfate
10. 10
    Filtrationfiltered
11. 11
    Sonstigeevaporated

Vorschrift

To a solution of tert-butyl 3-oxopyrrolidine-1-carboxylate (370 mg) in tetrahydrofuran (20 mL) at −78° C. was added sodium bis(trimethylsilyl)amide (4.18 mL, 1.0M in tetrahydrofuran). The reaction mixture was stirred for 1.5 h, then treated with acetic anhydride (0.21 mL) and stirred at room temperature for 20 min. The reaction mixture was quenched by the dropwise addition of water and concentrated under vacuum. To the basic residue, ethyl acetate (50 mL) and saturated aqueous sodium bicarbonate solution (30 mL) with an equal volume of water were added. The aqueous layer was separated, acidified by careful addition of hydrochloric acid to pH 3 and extracted with ethyl acetate (75 mL). The organic layer was washed with brine, dried over anhydrous sodium sulfate, filtered and evaporated to yield desired product which was used in the next step without further purification.

Quelle