Sulfuric Acid → 2,3-Dichloro-1-oxo-1lambda~5~-pyrazine

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Reaction Steps

To a stirred solution of 750 g. (5 mol) of 2,3-dichloropyrazine* in 5 l. of sulfuric acid at 10° C., is gradually added 1,500 g. (5.5 mol) of potassium persulfate. The reaction mixture is stirred at room temperature for 24 hours and carefully poured into 19 l. of ice water. The aqueous solution is extracted with chloroform and the extract is washed with sat. NaHCO3 and sat. NaCl solutions and dried over MgSO4. Evaporation of the solvent provides 698 g. (85%) of white solid. MP 101°-103° C. (lit. MP 104°-106° C.). This material is used without further purification.

Provenance & Evidence