Fragmentation of substituted 4-hydroxy-2-quinolones under the influence of electron impact

The general principles of the mass-spectral disintegration of 4-hydroxy-2-quinoline derivatives containing various substituents attached to the nitrogen in the 3 position were established. It was found that the disintegration of 4-hydroxy-2-quinolone and its N-substituted derivatives proceeds primarily through cleavage of the heterocyclic ring, while the principal pathways of the disintegration of 3-acyl derivatives are associated with fragmentation of the acyl group.