Loss of isocyanic acid from the internal oxadiazole ring of protonated molecules of some 2,5-diaryl-1,3,4-oxadiazoles was written by Franski, Rafal;Schroeder, Grzegorz;Rybachenko, Volodymir;Szwajka, Oles P.. And the article was included in Rapid Communications in Mass Spectrometry in 2002.Formula: C12H8N4O This article mentions the following:
The fragmentation pattern of some protonated 2,5-diaryl-1,3,4-oxadiazoles is discussed. An unusual decomposition consisting of elimination of the isocyanic acid mol. from the internal oxadiazole ring was found. This fragmentation pathway was deduced on the basis of B/E linked scan mass spectra of metastable ions with liquid secondary ion mass spectrometry as the ionization method and also of low-energy CID mass spectra where electrospray was used as the ionization technique. High resolution measurements were also performed. In the experiment, the researchers used many compounds, for example, 2,5-Di(pyridin-4-yl)-1,3,4-oxadiazole (cas: 15420-02-7Formula: C12H8N4O).
2,5-Di(pyridin-4-yl)-1,3,4-oxadiazole (cas: 15420-02-7) belongs to pyridine derivatives. Pyridine’s the lone pair does not contribute to the aromatic system but importantly influences the chemical properties of pyridine, as it easily supports bond formation via an electrophilic attack. One of the examples of pyridines is the well-known alkaloid lithoprimidine, which is an A3 adenosine receptor antagonist and N,N-dimethylaminopyridine (DMAP) analog, commonly used in organic synthesis.Formula: C12H8N4O