Reaktion #6587

Reaktionsgleichung

phenylacetylene

N-methoxy-N-methylbenzamide

lithium diisopropylamide

tetrahydrofuran

→

title compound

Ausbeute 61.4%

1-Phenyl-3-phenyl-2-propyne-1-one

Ausbeute 61.4%

Lösungsmittel

cyclohexane

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeRemove the cooling bath
2. 2
   TemperaturCool the yellow solution to 0° C.
3. 3
   SonstigeRemove the cooling bath
4. 4
   workup.STIRRINGstir for 30 minutes at room temperature
5. 5
   workup.ADDITIONPour onto ethyl ether and water
6. 6
   Sonstigeseparate the organic phase
7. 7
   Trocknendry (MgSO4)
8. 8
   FiltrationFilter
9. 9
   Sonstigeevaporate the solvent in vacuo
10. 10
    Sonstigeto yield an oil
11. 11
    SonstigePurify by silica gel chromatography (2% ethyl acetate/hexane)
12. 12
    workup.DISTILLATIONthen purify further by distillation (2×)

Vorschrift

Place lithium diisopropylamide (10 mL of a 1.5M solution in cyclohexane) and tetrahydrofuran (40 mL) under an argon atmosphere and cool to 0° C. Add, by dropwise addition, phenylacetylene (1.65 mL, 15 mmol). Remove the cooling bath and stir for 30 minutes as room temperature. Cool the yellow solution to 0° C. and add, by dropwise addition, N-methoxy-N-methylbenzamide (3.04 mL, 20 mmol). Remove the cooling bath and stir for 30 minutes at room temperature. Pour onto ethyl ether and water, separate the organic phase and dry (MgSO4). Filter and evaporate the solvent in vacuo to yield an oil. Purify by silica gel chromatography (2% ethyl acetate/hexane) then purify further by distillation (2×) to yield 1.9 g of the title compound; bp 210° C. in vacuo.

Quelle