Ethyl oleate (1) reacts with hydrazine hydrate to form stearic acid hydrazide (2), the reaction proceeds with the simultaneous reduction of 9,10 C=C bond of ethyl oleate. The stearic acid hydrazide formed on intermolecular cyclisation with different aliphatic acids, aromatic acids (3), or ethyl oleate (1) in the presence of phosphorus oxychloride forms 2,5-disubstituted 1,3,4-oxadiazoles (4) in good yield. The structure proofs of the product were confirmed by spectral studies and elemental analysis
