Reaktion #2075760

Reaktionsgleichung

4,4′-difluorobenzophenone

piperazine

sodium hydroxide

triethylsilane

sulfuric acid

sodium hydrogenbicarbonate

→

1-[4-(4-fluorophenyl)methylphenyl]piperazine

Ausbeute 58.0%

Lösungsmittel

triethylamine

acetonitrile

trifluoroacetic acid

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturAfter cooling to room temperature
2. 2
   Extraktionby extracting with chloroform
3. 3
   SonstigeThe extract was dried
4. 4
   Filtrationfiltered
5. 5
   Einengenconcentrated under reduced pressure
6. 6
   SonstigeThe residue obtained
7. 7
   workup.STIRRINGstirred at room temperature for 1 hour
8. 8
   Extraktionby extracting with ethyl acetate
9. 9
   SonstigeThe extract was dried
10. 10
    Filtrationfiltered
11. 11
    Einengenconcentrated under reduced pressure
12. 12
    Sonstigeto give a residue, which
13. 13
    Sonstigewas purified by silica gel column chromatography (chloroform:methanol:water (2% acetic acid)=65:35:5)

Vorschrift

To a 10 ml acetonitrile solution of 426 mg of 4,4′-difluorobenzophenone and 841 mg of piperazine, 395 mg of triethylamine was added and stirred at 100° C. for 12 hours. After cooling to room temperature, saturated aqueous sodium hydrogenbicarbonate solution was added, followed by extracting with chloroform. The extract was dried, filtered and concentrated under reduced pressure. The residue obtained was dissolved in 5 ml of trifluoroacetic acid and treated with 520 mg of triethylsilane and 60 mg of concentrated sulfuric acid, and stirred at room temperature for 1 hour. The reaction mixture was adjusted to pH=9 to 11 with 10% aqueous sodium hydroxide solution, followed by extracting with ethyl acetate. The extract was dried, filtered and concentrated under reduced pressure to give a residue, which was purified by silica gel column chromatography (chloroform:methanol:water (2% acetic acid)=65:35:5) to give the above-referenced compound, 1-[4-(4-fluorophenyl)methylphenyl]piperazine in an amount of 305 mg (yield 58%).

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