SYNTHESIS AND MASS-SPECTRAL STUDIES OF SOME AZOLE-BASED BIHETEROCYCLES .1.

The synthesis and mass spectrometric investigations of some azole-base d biheterocycles containing N and S and some of their N-methylated ana logues are discussed. The major fragmentation in imidazole based bihet erocycles involves decomposition of the azole ring with the loss of HC N, CH3, CN, C2H2 etc. along with azininium radical. For the methylated analogues structures involving ring expansion with skeletal rearrange ments have been proposed. In thiazole based biheterocycle the loss of neutral species provides the plausible pathways for the observed fragm entation pattern.