Reaktion #412788

Reaktionsgleichung

dimethylformamide

cyanopyrazine

sulfonyl chloride

→

title compound

Ausbeute 65.2%

Chlorocyanopyrazine

Ausbeute 65.2%

Lösungsmittel

benzene

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeprepared in Step A above
2. 2
   workup.STIRRINGafter which it was stirred for 5 hours
3. 3
   SonstigeThe benzene layer was decanted
4. 4
   Extraktionthe reddish oil residue was extracted three times with ether
5. 5
   Sonstigeafter which the combined benzene and ether layers were quenched with ice water
6. 6
   Temperaturcooled in an ice bath
7. 7
   Sonstigeseparated
8. 8
   Extraktionthe aqueous layer was extracted with ether
9. 9
   WaschenThe combined organic layers were washed once with a small amount of water
10. 10
    Trocknendried with sodium sulfate
11. 11
    Filtrationfiltered
12. 12
    Sonstigethe solvent evaporated

Vorschrift

In 90 ml of benzene and 9.2 ml of dimethylformamide there was stirred at room temperature cyanopyrazine (12.7 g; 0.12 M) prepared in Step A above, after which there was added over 10 minutes sulfonyl chloride (64.79 g; 0.48 M). The reaction mixture was stirred for 30 minutes in an ice bath, then allowed to warm up to room temperature gradually, after which it was stirred for 5 hours. The benzene layer was decanted, and the reddish oil residue was extracted three times with ether, after which the combined benzene and ether layers were quenched with ice water and cooled in an ice bath. The combined layers were then neutralized with solid sodium bicarbonate, then separated, and the aqueous layer was extracted with ether. The combined organic layers were washed once with a small amount of water, dried with sodium sulfate, filtered, and the solvent evaporated to give the title compound (11 g).

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