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 gamma,gamma-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.