Reaktion #622824

Reaktionsgleichung

Vinyl pyridine

piperazine

sodium hydroxide

→

1-[2-(2-Pyridyl)ethyl]piperazine

Lösungsmittel

water

H2O

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturHeating
2. 2
   WaschenThe reaction mixture was washed with toluene (2×175 mL)
3. 3
   workup.WAITThe aqueous layer was slowly adjusted to pH 12.0-12.5 with a solution of aqueous NaOH (40.0% w/w) during 45-60 min at 20-30° C.
4. 4
   Waschenagain washed with toluene (175 mL)
5. 5
   ExtraktionThe aqueous layer was extracted with n-butanol (2×210 mL)
6. 6
   Sonstigen-Butanol was removed under reduced pressure until the residual volume
7. 7
   workup.ADDITIONXylene (35 mL) was added at 75-85° C.
8. 8
   Temperaturcooled to 20-25° C
9. 9
   TemperaturThe reaction solution was maintained for 1.0 h at 20-25° C.
10. 10
    Filtrationfiltered through celite
11. 11
    Waschenthe celite washed with xylene (35 mL)

Vorschrift

A solution of piperazine:2HCl:H2O (241 g, 1332 mmol) in water (245 mL) was heated at 60-70° C. Vinyl pyridine (38.0 g, 333 mmol) was slowly added during of 45-60 min at 60-70° C. Heating was continued for 45-60 min at 60-70° C. The reaction mixture was cooled to 20-25° C. The pH was slowly adjusted to 8.0-8.5 with a solution of aqueous sodium hydroxide (40.0% w/w) during 45-60 min at 20-30° C. The reaction mixture was washed with toluene (2×175 mL). The aqueous layer was slowly adjusted to pH 12.0-12.5 with a solution of aqueous NaOH (40.0% w/w) during 45-60 min at 20-30° C. and again washed with toluene (175 mL). The aqueous layer was extracted with n-butanol (2×210 mL). n-Butanol was removed under reduced pressure until the residual volume reached 100 mL. n-Butanol was swapped completely with xylene (2×210 mL) until the residual volume reached 100 mL. Xylene (35 mL) was added at 75-85° C. and then cooled to 20-25° C. The reaction solution was maintained for 1.0 h at 20-25° C. and then filtered through celite and the celite washed with xylene (35 mL). The combined xylene solution was used in the next step without isolation of the product.

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