Réaction #6587

Équation de réaction

phenylacetylene

N-methoxy-N-methylbenzamide

lithium diisopropylamide

tetrahydrofuran

→

title compound

Rendement 61.4%

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

Rendement 61.4%

Solvants

cyclohexane

Conditions de réaction

Traitement

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

Mode opératoire

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.

Source