Reaktion #987617

Reaktionsgleichung

4-Methylpyrimidine

Lithium diisopropylamide

N-methoxy-N-methylacetamide

→

(4-Pyrimidyl)acetone

Lösungsmittel

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGThe reaction mixture was stirred at −78° C. for a further 40 minutes
2. 2
   Temperaturto warm to room temperature over 1.25 h
3. 3
   Sonstigepartitioned between saturated aqueous sodium carbonate and ethyl acetate
4. 4
   SonstigeThe layers were separated
5. 5
   Extraktionthe aqueous phase further extracted with ethyl acetate
6. 6
   WaschenThe combined extracts were washed with brine
7. 7
   Trocknendried (MgSO4)
8. 8
   Filtrationfiltered
9. 9
   Sonstigeevaporated
10. 10
    SonstigeThe residue was purified by column chromatography on silica gel eluting with 40-50% ethyl acetate in hexane
11. 11
    Sonstigeto give an oil which
12. 12
    Sonstigecrystallised

Vorschrift

4-Methylpyrimidine (2 g) was stirred in dry tetrahydrofuran (65 ml) under argon and the solution was cooled to −78° C. Lithium diisopropylamide (13.8 ml, 2M solution) was added dropwise over 20 minutes and stirring was continued at −78° C. for 1.5 h before dropwise addition of N-methoxy-N-methylacetamide (2.49 ml). The reaction mixture was stirred at −78° C. for a further 40 minutes before allowing to warm to room temperature over 1.25 h, then partitioned between saturated aqueous sodium carbonate and ethyl acetate. The layers were separated and the aqueous phase further extracted with ethyl acetate. The combined extracts were washed with brine, dried (MgSO4), filtered and evaporated. The residue was purified by column chromatography on silica gel eluting with 40-50% ethyl acetate in hexane to give an oil which crystallised on standing (0.70 g, 24%).

Quelle