Reaktion #953934

Reaktionsgleichung

hydrochloric acid

sodium sulfide nonahydrate

3-chloropyrazine-1-oxide

chloromethylthiocyanate

→

3-(thiocyanatomethylthio)pyrazine-1-oxide

Lösungsmittel

dimethylformamide

dimethylformamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGthe mixture stirred for 4 hours
2. 2
   SonstigeAt the completion of the reaction
3. 3
   Sonstigethe dimethylformamide was removed by evaporation under reduced pressure
4. 4
   workup.DISSOLUTIONthe residue was dissolved in a mixture of water and chloroform
5. 5
   SonstigeTwo phases formed
6. 6
   Extraktionextracted with chloroform
7. 7
   Waschenwashed with both a saturated sodium bicarbonate solution
8. 8
   Trocknena saturated sodium chloride solution and dried over magnesium sulfate
9. 9
   SonstigeThe chloroform was thereafter removed by evaporation

Vorschrift

To a vigorously stirred solution of 9.6 grams (0.04 mole) of sodium sulfide nonahydrate in 100 milliliters of dimethylformamide was gradually added 5.2 grams (0.04 mole) of 3-chloropyrazine-1-oxide in 50 milliliters of dimethylformamide. The reaction mixture was stirred overnight at 45°-50° C. Thereafter, 4.3 grams (0.04 mole) of chloromethylthiocyanate were gradually added and the mixture stirred for 4 hours. At the completion of the reaction, the dimethylformamide was removed by evaporation under reduced pressure and the residue was dissolved in a mixture of water and chloroform. Two phases formed and the aqueous phase was acidified with hydrochloric acid and extracted with chloroform. The organic portions were combined and washed with both a saturated sodium bicarbonate solution and a saturated sodium chloride solution and dried over magnesium sulfate. The chloroform was thereafter removed by evaporation leaving the 3-(thiocyanatomethylthio)pyrazine-1-oxide as a residue. The product was recrystallized from methanol and was recovered in a yield of 4.75 grams (60 percent of theoretical). The product melted at 104°-106° C and upon analysis was found to have carbon, hydrogen, nitrogen and sulfur contents of 36.40, 2.66, 20.59 and 32.20 percent, respectively, as compared with the theoretical contents of 36.18, 2.51, 21.11 and 32.16 percent, respectively, as calculated for the above-named compound.

Quelle