Synthesis and mass spectral fragmentation patterns of some nitrogen heterocycles with antimicrobial activity.

5-( P-tolyl)-2-[(3-bromo-4-methoxy benzylidene) hydrazino]-thiazole 3, 3-[(3-bromo-4-mehtoxy benzylidine) amino]-2-thiohydantion 5, and 4,6-disubstituted-3-[(3-bromo-4-methoxybenzyliden) amino]-2-thioxo pyrimidines 10 have been prepared via cyclization of 3-bromo-4-methoxy benzaldehyde thiosemicarbazone 2 with 4-methyl phenacyl bromide, ethyl chloroacetate, and dicarbonyl compounds in different conditions. Acetylation of 3 and 5 with acetic anhydride gave the corresponding monoacetyl derivatives 4 and 6, while the acetylation of 5 with acetic anhydride in the presence of fused sodium acetate gave diacetyl derivative 7. Condensation of compound 5 with benzaldehyde in the presence of piperidine yielded the corresponding 3-substituted-5-benzylindene 2-thiohydation 8. Acetylation of compound 8 with acetic anhydride gave the corresponding 1-acetyl-3-substituted-5-benzylidene-2-thiohydantion 9. The mass spectral fragmentation patterns of some prepared compounds are investigated in order to elucidate the structure of the synthesized nitrogen heterocycles. [ABSTRACT FROM AUTHOR]