Synthesis, characterization and electron impact mass spectrometry of Schiff bases rearranging to oxazoline, thiazoline and thiazole derivatives

A series of oxazoline compounds have been prepared by reaction of 2,6-diformyl-4-chlorophenol, 2,6-diformylpyridine or 2,5-diformylthiophen with o-aminophenol or o-aminothiophenol respectively. The oxazoline derivatives are stable both in solid state and in solution while the thiazoline derivatives easily oxidize to the corresponding thiazoles. Physico-chemical data confirm this oxidation process. The 70 eV electron impact induced decomposition pathways of these compounds, obtained with the aid of exact mass measurements, B/E linked scans and collisional spectroscopy, are discussed in detail.