Synthesis Characterization and Biological Evaluation of substituted Oxadiazole Derivatives

Abstract

Large numbers of nonsteroidal anti-inflammatory medicines are available to treat newlineacute and chronic inflammatory disorders. However, most of these drugs cause lots of newlineside effects like gastrointestinal hemorrhage, ulceration and renal disorder etc. Due to newlinethese side/ adverse effects of the existing NSAID s a need for exploring newer newlinemolecules that are free from these side effects. Hence the present investigation is newlinetaken up. The present investigation involves the synthesis of newer molecules derived newlinefrom different existing NSAIDs and Antimicrobial agent and also evaluates their antiinflammatory newlineand antimicrobial activity. newlineIn the present research work, I have synthesized twenty-four title compounds from newlinedifferent NSAID s and antimicrobial agents. The Ibuprofen/Aspirin/Ciprofloxacin newlinewas converted to its methyl ester by esterification. This ester was reacted with newlinehydrazine hydrate to afford carbohydrazide of Ibuprofen/Aspirin/Ciprofloxacin newlinerespectively. This carbohydrazide was treated with CS2 and KOH in methanol to newlineafford oxadiazole ring attached with Ibuprofen/Aspirin/Ciprofloxacin. Reaction of newlineoxadiazole with various 1°/2° amines and formaldehyde in ethanol formed various newlinederivatives of oxadiazole. The purity of the synthesized compounds newlinewas confirmed by melting point and thin-layer chromatography (TLC) on silica gel G. newlineThe structure of the newly synthesized derivatives was characterized by CHN analysis newlineand spectral studies i.e. IR, NMR and Mass spectroscopy. The IR spectra of the title newlinecompounds 1.IVa-h, 2.IVa-h and 3.IVa-h showed moderately strong bands around newline1520 1650 and 1224 1360- which are characteristic of the C=N and C=S groups newlinerespectively. In 1H NMR spectra the characteristic aromatic protons appeared as newlinemultiplets between and#948; 6.90-8.23 ppm while the protons signals of various secondary newlineamines were observed around and#948; 1.00-2.85 ppm, respectively. In 13C NMR spectrum, newlinecharacteristic signals appeared at around and#948; 175.13 176.33, strongly suggesting the newlinepresence of C=S (of oxadiazole).