Mass spectrometric studies of 3-substituted-5-amino-1,3,4-thiadiazolin-2-ones

Abstract

Fragment pathways of 3-alkyl and acyl-5-amino-1,3,4-thiadiazolin-2-ones were completely assigned by mass analyzed kinetic energy spectra (MIKE), collisional activated dissociation (CAD) spectra and high resolution mass spectra. [NH2CS](+) and [S=C=O](+) ions were directly formed from molecular ion of the 3-alkyl compounds and from 5-amino-3H-1,3,4-thiadiazolin-2-one ion (1) which was produced by McLafferty rearrangement from molecular ion of 3-acyl compounds. A loss of neutral SCO was only detected from 3-alkyl substituted molecular ions.