Synthesis of 3-aryl-5-decapentyl-1,2,4-oxadiazoles possessing antiinflammatory and antitumor properties

A simple, convenient and straightforward synthesis of 3-aryl-1,2,4-oxadiazoles 4a–f from arylamidoximes 1a–f and palmitic acid 2 is described. Compounds 4a–f are non-lethal in mice at four times the therapeutic dose (i.p., LD₅₀ > 1 g kg^–1 of the animals' body weight). These heterocycles have been found to possess antiinflammatory property similar to aspirin and ibuprofen. Three compounds, viz., 4a, d, e have also been evaluated for antitumor activity, where 4d exhibited an excellent activity comparable to lapachol.