Reaktion #584749

Reaktionsgleichung

Methyl magnesium bromide

tert-butyl (1S)-2-[methoxy(methyl)amino]-1-methyl-2-oxoethylcarbamate

ammonium chloride

→

title compound

Ausbeute 51.0%

tert-Butyl (1S)-1-methyl-2-oxopropylcarbamate

Ausbeute 51.0%

Lösungsmittel

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   Extraktionaqueous phase was extracted with diethyl ether (2×76 ml)
2. 2
   WaschenThe combined organic extracts were then washed with saturated aqueous ammonium chloride solution and brine
3. 3
   TrocknenThe organic phase was then dried (MgSO4)
4. 4
   Filtrationfiltered
5. 5
   Einengenconcentrated under reduced pressure
6. 6
   SonstigeThe residue was purified by column chromatography on silica gel
7. 7
   Wascheneluting with a solvent gradient of dichloromethane:methanol (99:1 to 98:2)

Vorschrift

Methyl magnesium bromide (3.0M solution in diethyl ether, 4.3 ml, 12.9 mmol) was added to a stirred solution of tert-butyl (1S)-2-[methoxy(methyl)amino]-1-methyl-2-oxoethylcarbamate (Tetrahedron: Asymmetry 1996, 7, 985) (1 g, 4.3 mmol) in anhydrous tetrahydrofuran (20 ml) at −60° C. under a nitrogen atmosphere. The mixture was allowed to warm to 0° C. and to then room temperature and was stirred at room temperature for 1 hour. Aqueous saturated ammonium chloride was added and aqueous phase was extracted with diethyl ether (2×76 ml). The combined organic extracts were then washed with saturated aqueous ammonium chloride solution and brine. The organic phase was then dried (MgSO4), filtered, and concentrated under reduced pressure. The residue was purified by column chromatography on silica gel, eluting with a solvent gradient of dichloromethane:methanol (99:1 to 98:2), to afford the title compound as a colorless solid, 412 mg, 51% yield.

Quelle