Dehydrogenation of piperazine into pyrazine on alumina-platinum catalysts

Dehydrogenation of piperazine on alumina-platinum catalysts at 360–400°C was investigated. It was found that the alumina-platinum catalyst has low selectivity in the formation of pyrazine (yield ≤43%), and dehydrogenation is accompanied by decomposition and coke formation and products of decomposition in the formation of alkylpyrazines. The alumina-platinum catalyst in In2O3 and Re2O7 additives permits obtaining pyrazine with a yield of up to 80%. Dehydrogenation of piperazine is accompanied by reactions of decomposition, dehydroisomerization, and alkylation to a small degree, resulting in the formation of pyrrole, methylimidazole, and alkylpyrazines.