Electron impact mass spectra of some acridones substituted with hydroxyl, methoxyl, alkyl and alkenyl groups

Forty‐four acridones were examined by mass Spectrometry. The fragmentations were studied, and included cleavage of the carbonoxygen bond of methoxyl groups, cleavage of the carbon–carbon bonds of γ,γ‐dimethylpyranyl groups, cleavage of isoprenyl groups and the formation of doubly charged molecular ions and daughter ions. The tendency for fission of carbonoxygen bond in the methoxyl group for acridones is about 300 : 200 : 8 : 1 for the C(2), C(4), C(5) and C(6) positions, respectively. The isoprenyl group is very sensitive to its position in fragmentation, and mass Spectrometry can be a powerful aid in distinguishing between C(2)‐ and C(4)‐isoprenyl isomers.