2.3- Dichloro-5,6-dicyanopyrazine

Preparation of 53 by the reaction of 2,3-dichloro-5,6-dicyanopyrazine (Section V,D,2) with ammonia in dimethylformamide has been reported (78MI1). 

Bis-[3,4-b, 4,3-e]thiophenylpyrazines can also be prepared from 2,6-dichloro-3,5-dicyanopyrazine and sodium thioglycolate, but in lower yields than for the corresponding pyridine derivatives <2004T275>. 

Some chlorinations have been reported with thionyl chloride. 23-Dicyano-5,6-dihydroxypyrazine refluxed with thionyl chloride in pyridine was reported to give 23-dichloro-5,6-dicyanopyrazine (862) and 2-hydroxy-3-nitro-5,6-diphenyl-pyrazine with thionyl chloride gave 2-chloro-3-hydroxy-5,6-diphenylpyrazine (817, 841) but with thionyl chloride and pyridine it gave the betaine of 2-hydroxy-5,6-diphenyl-3-pyridiniopyrazine chloride (5) (863), which was hydrolyzed in acid to 2,3-dihydroxy-5,6-diphenylpyrazine (863). No product could be isolated from 2-methylpyrazine when refluxed with thionyl chloride (864). 1,4-Dimethylpiperazine-... 

Dinitrile [56413-95-7]. 2,2-Dichloro-5,6-dicyanopyrazine C CljN M 198.998 Readily accessible intermed. for polycyclic heteroaromatics. Needles (CHCI3). Mp 179-180°. 

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