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Abstract

Pyrazoles and fused heterocyclic pyrazoles derivatives constitute an interesting class of heterocyclic compounds due to their synthetic versatility and effective biological activity in the field of pharmaceutical science, agriculture etc. In the present study, new substituted pyrazoles were prepared by condensation of substituted primary amine and ethyl acetoacetate at 140 0 C to form analides as intermediate. These intermediates on further reaction with hydrazine hydrate using ethanol as solvent and converted into pyrazoles. The synthesized compounds were characterised by their physical properties, IR, NMR and elemental analysis techniques. The purity of the compounds and completion of reaction was tested by TLC Technique using ethyl acetate and petroleum ether as an eluent (6:4). The antimicrobial activity of synthesized pyrazoles was assessed by Disk diffusion method using gram positive and gram negative strains. The benzoyl and nitroso derivatives were also prepared to confirm the formation of new compounds. The derivative of these compounds also shows good antimicrobial activity. INTRODUCTION: The chemistry of heterocyclic compounds is one of the most complex and important stream of organic chemistry. Because of the diverse properties, easily accessible path and the wide range of biological activities, these are centre of attraction for organic chemist to synthesise various heterocyclic compounds 1-3. The literature survey reveals the importance of pyrazole derivatives as an intermediate in the medicinal chemistry 4-6. Pyrazoles and their substituted derivatives are interesting potential pharmaceuticals. They exhibit wide variety of biological and pharmaceutical activities. Therefore, they play important role in medicinal chemistry 7 .