Reaktion #40680

Reaktionsgleichung

lithium chloride

potassium carbonate

m-cresol

t-butyl (1R)-2-(benzyloxy)-1-(hydroxymethyl)ethylcarbamate

methanesulfonyl chloride

→

t-butyl (1S)-2-(benzyloxy)-1-[(3-methylphenoxy)methyl]ethylcarbamate

Lösungsmittel

dimethylformamide

dichloromethane

dimethylformamide

ethyl acetate

dichloromethane

triethylamine

Reaktionsbedingungen

Aufarbeitung

1. 1
   Waschenafter washing with water
2. 2
   Trocknenthe organic layer was dried over anhydrous sodium sulfate
3. 3
   SonstigeThe solvent was evaporated
4. 4
   Sonstigeto give a crude product
5. 5
   workup.STIRRINGthe mixture was stirred overnight at 40° C
6. 6
   SonstigeThe solvent was evaporated
7. 7
   workup.ADDITIONthe residue was diluted with ethyl acetate
8. 8
   Waschenwashed with water
9. 9
   TrocknenThe organic layer was dried over anhydrous sodium sulfate
10. 10
    Sonstigethe solvent was evaporated
11. 11
    Sonstigeto give a crude product
12. 12
    workup.STIRRINGthe mixture was stirred overnight at 90° C
13. 13
    Waschenafter washing with water
14. 14
    Trocknenthe organic layer was dried over anhydrous sodium sulfate
15. 15
    SonstigeThe solvent was evaporated
16. 16
    Sonstigethe obtained crude product
17. 17
    Sonstigewas purified by silica gel chromatography (ethyl acetate-hexane)

Vorschrift

To t-butyl (1R)-2-(benzyloxy)-1-(hydroxymethyl)ethylcarbamate (3.23 g) obtained in Step 1 were added dichloromethane (40 ml), methanesulfonyl chloride (1.07 ml) and triethylamine (3.20 ml), and the mixture was stirred at 0° C. for 3 hrs. The reaction mixture was diluted with dichloromethane and, after washing with water, the organic layer was dried over anhydrous sodium sulfate. The solvent was evaporated to give a crude product. To this crude product were added dimethylformamide (30 ml) and lithium chloride (2.4 g), and the mixture was stirred overnight at 40° C. The solvent was evaporated, and the residue was diluted with ethyl acetate and washed with water. The organic layer was dried over anhydrous sodium sulfate, and the solvent was evaporated to give a crude product. To this crude product were added dimethylformamide (20 ml), potassium carbonate (2.4 g) and m-cresol (1.47 ml), and the mixture was stirred overnight at 90° C. The mixture was diluted with ethyl acetate and, after washing with water, the organic layer was dried over anhydrous sodium sulfate. The solvent was evaporated and the obtained crude product was purified by silica gel chromatography (ethyl acetate-hexane) to give t-butyl (1S)-2-(benzyloxy)-1-[(3-methylphenoxy)methyl]ethylcarbamate (1.5 g).

Quelle