Glyoxal bishydrazones through facile ring cleavage of hydrazinopyrazine by hydrazines

The reaction of chloropyrazine and hydrazine was reinvestigated and was shown to produce hydrazinopyrazine and glyoxal bishydrazone. The latter was obtained also when hydrazine hydrochloride was allowed to react with Hydrazinopyrazine. The fusion of hydrazinopyrazine at 160° produced glyoxal his(pyrazinythydrazone). The interconversions of glyoxal bishydrazone with Hydrazinopyrazine were studied. Mechanisms to explain the various transformations are discussed.