SYNTHESIS AND IN- VITRO ANTIOXIDANT ACTIVITY OF SOME NEW 2, 5-DISUBSTITUTED-1, 3, 4-OXADIAZOLES CONTAINING FURAN MOIETY

A series of five membered heterocyclics was synthesized by the reaction between refluxing 2 - furoic acid with ethanol and conc. H2SO4. The obtained ester (2) with hydrazine hydrate and ethanol was refluxed to give hydrazides (3). Reaction of hydrazides (3) with different aromatic acids using phosphorousoxy trichloride (POCl3) lead to the formation of 2-Aryl - 5-furyl 1, 3, 4-oxadiazoles [DM (1-6)], and was tested for their antioxidant activity. The synthesized compounds were characterized by IR, (HNMR)-H-1 and Mass Spectroscopy. All the compounds were screened for in vitro antioxidant activity by DPPH method and nitric oxide scavenging assay. Among the synthesized compounds DM-1, DM-2 and DM-4 were found to be promising compounds of the series substituted with electron donating groups like methoxy and hydroxyl showed higher antioxidant activity.