Electron impact studies on 2-hydroxyimino-N-aryl acetamides

The mass spectra of 13 2-hydroxyimino-N-aryl acetamides contain abundant arylamine, isocyanate and protonated benzimidazole ions, the mechanisms of formation of which were established by deuterium labelling and formulae by exact mass measurements. Loss of OH˙ and NO˙ were postulated to proceed through cyclic and acyclic intermediates respectively. Considerable hydrogen scrambling and rearrangement could be noticed in all the processes.