Heterocyclic studies—XXV: Mass spectra of some 4-trifluoromethylpteridine derivatives

Mass spectra of 4-trifluoromethylpteridine and nine of its derivatives are recorded. Electron impact induced fragmentations of 4-trifluoromethylpteridine and its 2-chloro-, 7-methyl- and 6, 7-dimethyl-derivatives resemble those of pteridine and simple methylpteridines except that loss of a trifluoromethyl radical usually intervenes at some stage. Fragmentation of 4-trifluoromethyl-pteridine derivatives with an amino, substituted-amino, alkoxy or alkylthio group in the 2-position fragment by a variety of mechanisms. Accurate mass measurements and deuterium labelling were used to help elucidate some fragmentation pathways.