Reaktion #215558

Reaktionsgleichung

2,3-Dicyano-5-hydroxypyrazine

thionyl chloride

pyridine

→

2,3-dicyano-5-chloropyrazine

Ausbeute 77.0%

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturthe solution was cooled to 0° to 5° C
2. 2
   workup.STIRRINGThen, the mixture was stirred at 70° C. for 2 hours
3. 3
   SonstigeAfter the reaction
4. 4
   workup.DISTILLATIONthe excess of thionyl chloride was distilled off under reduced pressure
5. 5
   Extraktionthe residue was extracted with 150 ml of chloroform
6. 6
   WaschenThe chloroform solution was washed twice with 50 ml of water
7. 7
   Trocknendried over anhydrous calcium chloride
8. 8
   workup.DISTILLATIONthe solvent was distilled off
9. 9
   Sonstigeto afford a red solid
10. 10
    SonstigeRecrystallization of the solid from benzene

Vorschrift

2,3-Dicyano-5-hydroxypyrazine (7.30 g; 0.05 mole) was dissolved in 70 g (0.59 mole) of thionyl chloride, and the solution was cooled to 0° to 5° C. With stirring, 4.80 g (0.06 mole) of pyridine was added dropwise over the period of 15 minutes. Then, the mixture was stirred at 70° C. for 2 hours. After the reaction, the excess of thionyl chloride was distilled off under reduced pressure, and the residue was extracted with 150 ml of chloroform. The chloroform solution was washed twice with 50 ml of water, and dried over anhydrous calcium chloride, and then the solvent was distilled off to afford a red solid. Recrystallization of the solid from benzene afforded 6.30 g (yield 77%) of 2,3-dicyano-5-chloropyrazine.

Quelle