Intermolecular and intramolecular cyclization over modified ZSM-5 and chrornite catalysts to synthesize 2-methylpyrazine and piperazine

Abstract

The synthesis of methyl pyrazine and piperazine has been carried out over HZSM-5 and modified copper-chromite catalysts. The reaction occurs through the dehydrocyclization route at acidic centres. The, Bronsted acidic centres at interstitial are particularly responsible for the conversion of propylene glycpl, propylene oxide with ethylenediamine and β-hydroxy-propylethylenediamine to the N-containing heterocycles through intermolecular and intramolecular cyclization. In the formation of N-containing heterocycles, the steps involved are dehydration and cyclization. The important difference between these reactions and the methanol-to-gasoline (MTG) process is the formation of olefinic compounds as intermediates in the latter.