Synthesis, characterization and biological evaluation of some 5-methylpyrazine carbohydrazide based hydrazones

Pyrazine carbohydrazide based hydrazones were synthesized starting from 5-methylpyrazine-2-carboxylic acid. The acid was first converted to its methyl ester, which on further treatment with hydrazine hydrate transformed to carbohydrazide. The carbohydrazide was treated with differently substituted aromatic carbonyl compounds giving hydrazones. Characterization of the synthesized compounds was carried out using modern spectroscopic techniques and unambiguously confirmed through X-ray crystallographic studies of compound 3d. The purity of the compounds was verified using elemental analysis. The target molecules were evaluated for urease inhibition, antioxidant and antimicrobial activity.