Reaktion #693427

Reaktionsgleichung

N,N-dimethylformaldehyde

n-butyllithium

2,2,6,6-tetramethylpiperidine

2-(tert-butoxycarbonylamino)pyrazine

→

2-(tert-butoxycarbonylamino)pyrazine-3-carboxaldehyde

Lösungsmittel

tetrahydrofuran

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwhile cooling on ice
2. 2
   workup.STIRRINGthe mixture was stirred for 1 hour
3. 3
   workup.STIRRINGstirring
4. 4
   workup.WAITwas continued for 30 minutes
5. 5
   SonstigeAfter removing the cooling bath
6. 6
   workup.STIRRINGstirring for 30 minutes
7. 7
   workup.ADDITIONwater was added
8. 8
   Extraktionextraction
9. 9
   SonstigeThe extract was dried
10. 10
    Einengenconcentrated
11. 11
    Sonstigepurified by silica gel column chromatography (solvent: ethyl acetate/n-hexane)

Vorschrift

After adding 4 ml of n-butyllithium (2.46 M, n-hexane solution) to a solution of 1.384 g of 2,2,6,6-tetramethylpiperidine in tetrahydrofuran (15 ml) at −20° C. under a nitrogen atmosphere, the mixture was stirred for 30 minutes while cooling on ice. The reaction mixture was cooled to −70° C., and then a solution of 800 mg of 2-(tert-butoxycarbonylamino)pyrazine in tetrahydrofuran (3 ml) was added dropwise, the mixture was stirred for 1 hour, 3 ml of N,N-dimethylformaldehyde was added, and stirring was continued for 30 minutes. After removing the cooling bath and stirring for 30 minutes, water was added and extraction was performed with ethyl acetate. The extract was dried and concentrated and then purified by silica gel column chromatography (solvent: ethyl acetate/n-hexane) to obtain 72 mg of crude 2-(tert-butoxycarbonylamino)pyrazine-3-carboxaldehyde.

Quelle