Reaktion #40756

Reaktionsgleichung

Malononitrile

DBU

1,4-dibromobutane

→

colorless liquid

Cyclopentane-1,1-dicarbonitrile

Lösungsmittel

DMF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturcooled in an ice bath
2. 2
   SonstigeThe ice bath was removed
3. 3
   workup.ADDITIONan extra 100 mL of dry DMF was added
4. 4
   TemperaturAfter cooling to ambient temperature
5. 5
   workup.ADDITIONDCM was added
6. 6
   Waschenthe mixture was washed 5 times with 5% aqueous NaHCO3
7. 7
   TrocknenThe organic phase was dried over Na2SO4
8. 8
   Sonstigeevaporated under reduced pressure
9. 9
   Sonstigeto give 40 g of a black oily substance
10. 10
    SonstigeThis was purified by flash chromatography
11. 11
    Wascheneluting with PA

Vorschrift

Malononitrile (15.0 g) was dissolved in dry DMF (200 mL) and cooled in an ice bath. Subsequently, DBU (75 mL, 2.2. equiv.) and 1,4-dibromobutane (29.6 mL, 1.1 equiv.) were added dropwise. The ice bath was removed, an extra 100 mL of dry DMF was added, and the mixture was stirred at 80° C. for 2 h. After cooling to ambient temperature, DCM was added and the mixture was washed 5 times with 5% aqueous NaHCO3. The organic phase was dried over Na2SO4 and evaporated under reduced pressure to give 40 g of a black oily substance. This was purified by flash chromatography eluting with PA:EA 9:1 (Rf=0.35, visualized with 12) to give 23.4 g of a colorless liquid. 1H NMR (400 MHz, CDCl3) δ 1.94-2.03 (m, 4H), 2.41 (t, J=7 Hz, 4H).

Quelle