ELECTRON IONISATION MASS SPECTRA OF SOME 
SULPHONYL-HYDRAZINO-THIAZOLES

N. Palibroda1, Z. Moldovan1, A. Pamula1, V. Zaharia2

1National Institute for Research and Development of 
Isotopic and Molecular Technologies Cluj-Napoca
2“Iuliu Hatieganu” University of Medicine and Pharmacy
Cluj-Napoca

The mass spectra under electron ionisation of some sulphonyl-hydrazino-thiazole derivatives
were investigated. The benzenesulphonyl-hydrazine part of the molecule had in three cases an acetyl substituent on the second nitrogen atom of the hydrazine moiety. The substituents on the thiazole ring were phenyl, methyl and chloromethyl, in position 4 of the ring. The substituents in position 5 of the ring were Br and acetyl. A total of ten derivatives were investigated. 
Mass spectra were recorded under electron impact ionisation on a MAT 311 mass spectrometer, using the repeated scan mode under temperature programmed heating of the sample. Samples were introduced using the direct inlet probe and the temperature was programmed from room temperature to 300 oC.
 
Molecular ions were generally of low intensity not exceeding 10% and in two cases out of ten were even missing.
Phenyl fragmentation next to the sulphone group gave ion m/z = 77 of prominent intensity, representing the base peak in the case of four of the compounds investigated. However M - 77 ions did not appear in any of the spectra investigated..
Fragmentation of the single bond between the benzenesulphonyl and the hydrazine moieties produces characteristic ions with electric charge on both sides, being accompanied in several cases by a proton transposition to the benzenesulphonyl group. Intensities of these ions are in the range of tens of percent.
No ions al all were produced by the fragmentation of the N - N bond in the hydrazine moiety. Ions produced by the fragmentation of the single bond between the hydrazine and the thiazole groups having the electric charge on the benzenesulphonyl-hydrazine side are also missing. The same fragmentation with the charge on the thiazole side produces however intense ions between 20 and 75%, being accompanied by a proton transposition to the thiazole ring.
In compounds having acetyl substituents m/z 43 is always the base peak and at the high mass end M - 42 ions appear in the spectrum in half of the cases.
A double fragmentation of the N-C and S-C in the thiazole ring did appear in some cases, producing ions that contain carbon atoms 4 and 5 of the thiazole ring together with their substituents.
Ion compositions were verified by exact mass determinations under high resolution R = 5000.