The mass spectra of acridones.

The mass spectra of 34 acridones have been determined and interpreted with the aid of both high-resolution measurements and deuterium labelling studies. The spectra contain pronounced molecular ions and are free of skeletal rearrangement fragments. The fragmentation patterns are dependent on the nature and position of substituents, and therefore mass spectrometry can be a useful aid to structure determination in this class of naturally occurring compounds.