Preparation, Thermal, and Antioxidant Properties of Aminoguanidinium 2,3-Pyrazine Dicarboxylates

Heteroaromatic acids containing a nitrogen atom (e.g., pyridine, pyrimidine, or pyrazine derivatives) are an interesting group of compounds with excellent biological properties. Aminoguanidinium (Agun) salts of 2,3-pyrazine dicarboxylic acid (H2pzdc) were synthesized (Hpzdc)(AgunH), (pzdc)(AgunH)2, (H2pzdc.Hpzdc)(AgunH) in 1:1, 2:1, and 1:2 molar ratios of base and acid, respectively. The synthesized salts were characterized by analytical, FTIR spectroscopic techniques. IR spectra of aminoguanidinium salts of H2pzdc show bands around 1113–1105 cm−1 assigned for N-N stretching frequency. Carboxylate groups exhibit asymmetric and symmetric stretching frequencies in the ranges of 1600–1550 cm−1 and 1436–1315 cm−1, respectively. Using simultaneous TG/DTA methods, the thermal strength and sensitivity of the amioguanidinium salts were assessed. 2,3-Pyrazine dicarboxylate salts decompose in two to three stages, yielding gaseous final products, as suggested by thermal experiments. The salts’ antioxidant capacities were investigated using the phosphomolybdenum, ferric reducing, and DPPH assessments. Assay findings revealed considerable ferric-reducing power, demonstrating the compounds capacity to donate hydrogen. Further, it shows that aminoguanidinium salt of 2,3-pyrazine dicarboxylic acid in the ratio of 2:1 has higher antioxidant properties by comparing with other different ratios.