With Two Halogeno and Other Substituents

In reactions with amines the 2-halogeno substituent was replaced from 2,5-dihalogeno-3-methoxycarbonylpyrazines (35) and 2,3-dichloro-5-methoxycarbonyl- 

5- dibromopyrazine with ammonium hydroxide or dimethylamine at 130°, or aqueous piperidine under reflux, gave 2,3-diamino-5-bromo-, 2-amino-5-bromo- 

3- dimethylamino(or piperidino)pyrazine, respectively (804). 3,6-Dibromo-l,4-diphenylpiperazine-2,5-dione with aniline gave 3,6-dianilino-l,4-diphenylpiperazine- 

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