Synthesis and evaluation of insecticidal activity of bis-semicarbazones and bis-(5-aryl substituted-1, 3, 4-oxadiazole)

Abstract

Background: Various substituted semicarbazones and oxadiazols have been widely investigated for their insecticidal and pharmacological activities. Heterocyclic analogs of these types were extensively studied for their biological activities. In this study insecticidal activity of semicarbazones and oxadiaziole created our interest to prepare and screen the activity. Objectives: To prepare a series of substituted semicarbazones and oxadiazoles, with an observation to subjecting them for insecticidal and pharmacological screening. Methodology: An oxalic acid dicarbohydrazide compound was prepared by a mixture of diethyl oxalate (0.1 mole), hydrazine hydrate (99%) (0.2 mole) and 2-3 drops of Conc. HCl in absolute ethanol. Resulted compound was reflexed with different substituted aldehyde (0.05 moles) with addition of 1-2 drops of Conc. HCl in an absolute ethanol to acquired bis-semicarbazones. Derived bis-semicarbazones were subjected for oxidation using ferrichloride (20mg) and acetic acid (8mL) to obtain oxadiazole derivatives. Results: The compounds 2c-d and 3a showed high percentage of mortality in an insecticidal activity. Compounds 3a and 3b exhibited high anti-bacterial activity against Kallipsi calla, in case of Escherichia coli the compound 2d, 3a, 3c and 3d shows maximum activity. Compounds 3a and 3d showed high anti-fungal activity against A. nigar and 3c against A. flavous. The compounds 2a, 2b, 3c have shown good anti-inflammatory activity. Compound 3d showed a competitive inhibitory activity and act as lead molecule towards the drug designing. Conclusion: The present study exposed that the synthesized compounds exhibit significant insecticidal, anti-bacterial, anti-fungal, anti-inflammatory activity and act as lead molecule towards the drug designing.