| Abstract: | The mass spectra of a variety of alkyl and aryl oxazoles have been determined and the spectra analyzed with the aid of deuterium labelling and high resolution mass spectrometry. In contrast to the corresponding benzenoid compounds, the mass spectra of isomeric alkyl oxazoles are distinctive and in this respect are akin to those of the corresponding pyridines. Further analogy to the pyridines is suggested by the unfavorable nature of a carbonium ion adjacent to the 2-position and this effect may be used to locate alkyl substituents attached to the oxazole nucleus. The loss of carbon monoxide from the molecular ions of 2,5-disubstituted oxazoles probably occurs with ring opening and migration of the C-5 substituent (e.g.Br) to the C-4 position. |
