Antiinflammatory Property of 3-Aryl-5-(n-propyl)-1,2,4-oxadiazoles and Antimicrobial Property of 3-Aryl-5-(n-propyl)-4,5-dihydro-1,2,4-oxadiazoles: Their Syntheses and Spectroscopic Studies Original Research Article

The synthesis of six 3-aryl-5-(n-propyl)-4,5dihydro-1,2,4-oxadiazoles 3a–f has been achieved in a facile manner by the reaction of an appropriate arylamidoxime 1a–f with butyraldehyde 2. Oxidation of 3a–f individually using MnO2 in CH2Cl2 or sodium hypochlorite in THF/H2O furnished 1,2,4-oxadiazoles 4a–f in good to excellent yields. Compounds 4a–f were also evaluated against inflammation. Except 4e, all of them reduced inflammation, however, 4c presented better antiinflammatory activity. A preliminary antimicrobial activity tests of 3a–f showed that these compounds possess activity against some microorganisms. In fact, 3c and 3f have been found to be more effective against Staphylococcus aureus, Mycobacterium smegmatis, and Candida albicans.