The apparent intervention of diimide during a pyridazine synthesis. A re-examination of the reaction between hydrazine and Pyrazine-2,3-dicarboxylic acid derivatives

Abstract

The reactions of pyrazine-2,3-dicarboxylic anhydride and dimethyl pyrazine-2,3-dicarboxylate with hydrazine have been shown to give products resulting from reduction of the pyrazino rings of theinitially formed pyrazino[2,3-d]pyridazine-5,8(6H,7H)-dione and 3,3'-hydrazodicarbonylbis(pyrazine-2-carboxylic acid). The level of reduction is substantially diminished when the reactions are carriedout in an inert atmosphere and it is therefore postulated that the reducing species is diimide.