1,3,4-Oxadiazole is a nitrogen and oxygen containing heterocycle, and one of the four isomers of oxadiazole.

[1][2] 1,3,4-Oxadiazole itself is not commonly used in organic chemistry, but many of its derivatives are important.

Other pharmaceutical drugs containing the 1,3,4-oxadiazole ring include fenadiazole, zibotentan, and tiodazosin.

[3] One pathway is from oxidation of tetrazoles in the presence of aldehydes.

[4] Similarly, the reaction of tetrazoles with acyl chlorides provides oxadiazoles.