A highly selective synthesis of pyrazine from ethylenediamine on copper oxide/copper chromite catalysts

Ethylenediamine (ED) vapor on passing over a series of copper oxide/copper chromite catalysts in the temperature range of 340–440 °C yielded pyrazine with a very high selectivity (98–100%), the reaction proceeds by intermolecular deamination and cyclization of ED to form piperazine, which undergoes subsequent dehydrogenation to form pyrazine. Reaction parameters like effect of temperature, contact time, reactant feed ratio and time on stream were found to have profound effect on the reactant conversion as well as the product selectivity.