Reaktion #215565

Reaktionsgleichung

Thioglycolic acid

2,3-dicyano-5-chloropyrazine

triethylamine

→

2,3-dicyano-5-(carboxymethylthio)pyrazine

Ausbeute 75.0%

Lösungsmittel

acetone

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwhile the solution was cooled to 0° to 5° C.
2. 2
   workup.ADDITIONAfter the addition
3. 3
   SonstigeThe precipitate was separated by filtration
4. 4
   EinengenThe filtrate was concentrated under reduced pressure, and 100 ml of a 1% aqueous solution of hydrochloric acid
5. 5
   workup.ADDITIONwas added
6. 6
   ExtraktionThe separated oily product was extracted with 50 ml of ethyl acetate
7. 7
   WaschenThe ethyl acetate layer was washed twice with 50 ml of a saturated aqueous solution of sodium chloride
8. 8
   Trocknendried over anhydrous sodium sulfate
9. 9
   Einengenconcentrated under reduced pressure
10. 10
    Sonstigeto afford a crude product
11. 11
    SonstigeRecrystallization from toluene

Vorschrift

Thioglycolic acid (0.92 g; 0.01 mole) and 1.64 g (0.01 mole) of 2,3-dicyano-5-chloropyrazine were dissolved in 40 ml of acetone, and while the solution was cooled to 0° to 5° C., 2.12 g (0.021 mole) of triethylamine was added dropwise. After the addition, the mixture was stirred at 20° to 25° C. for 2 hours. The precipitate was separated by filtration. The filtrate was concentrated under reduced pressure, and 100 ml of a 1% aqueous solution of hydrochloric acid was added. The separated oily product was extracted with 50 ml of ethyl acetate. The ethyl acetate layer was washed twice with 50 ml of a saturated aqueous solution of sodium chloride, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to afford a crude product. Recrystallization from toluene afforded 1.65 g (yield 75%) of 2,3-dicyano-5-(carboxymethylthio)pyrazine.

Quelle