Synthesis And Characterization Of Pyrazine Compounds

In this paper, new transition metal olefin polymerization catalysts with better catalytic capacity have been introduced based on Brookhart bis(imino)pyridyl-transition metal catalyst. It has been demonstrated by so many results that the catalyst structure is the key to the polymerization activity. A relatively straightforward modification to bis(imino)pyridyl ligands is to replace the pyridine with pyrazine The main studies are as fellows:With 2, 3, 5, 6-tetramethyl pyrazine as the starting material, 3, 6-dimethyl pyrazine-2, 5-dicarboxylic acid and diethyl 3, 6-dimethyl-2, 5-pyrazinedicarboxylate were obtained in good yields through a quite novel and straightforward method. All the compounds were characterized by elemental analysis, IR and UV, while two molecular structures were characterized by X-ray single crystal diffraction. Four complexes were obtained through hydrothermal reaction in aqua system and characterized by elemental analysis, IR and UV.A novel compound diethyl 3, 6-dimethyl-2, 5- pyrazinediacidamide have been obtained by ammonolysis of ester. At the same time, the mechanism of ammonolysis of ester has been investigated. Four complexes were obtained through hydrothermal reaction in aqua system and all compounds were characterized by elemental analyses, IR and UV.A new compound of benzimidazole derivative was obtained by the condensation reaction of 3, 6-Dimethyl pyrazine-2, 5-dicarboxylic acid and o-phenylenediamine under microwave without any solvent, in which artificial zeolitea and silica gel as the catalysts and catalytic amounts of DMF was used as the energy transfer medium. The compound was characterized by elemental analyses, IR, UV and ~1H NMR. The mechanism was studied here. The method of microwave irradiation in solvent-free condition is better than others.With 3, 6-Dimethyl pyrazine-2, 5-dicarboxylic acid as the starting material, five novel aromatic amines incorporated carboxamide pyrazine have been synthesized by chlorination and ammonolysis. They have been characterized by element analyses, IR, UV and ~1H NMR. The mechanism of amidation reaction has been studied.