Electron impact mass spectrometry of substituted 1,3,8-triazaspiro[4,5]decan-4-ones

The neuroleptic butyrophenone drug spiroperidol (8-[4-fluorophenyl)-4-oxobutyl]-1-phenyl-1,3,8-triazaspiro [4,5]decan-4-one) and related compounds are valuable tools for mapping the dopamine receptors in the brain. During the development of the radiochemical synthesis of these compounds with very short-lived isotopes suitable for positron emission tomography studies, positive electron impact mass spectrometric information was obtained. Ion series are present in the spectra of all 12 compounds studied, which unambiguously allow recognition of type and site of substitution on the spiro system.