Enaminonitrile 2 was used as key intermediate for the synthesis of polyfunctionally substituted heterocycles (e.g. pyrazoles, isoxazole, pyrimidines, thiazolo[3,2-a]pyrimidine, tetrazolo[1,5-a]pyrimidine, pyrido[1,2-a]pyrimidine, 1,5-benzodiazepine, and pyrazolo[1,5-a]pyrimidine) incorporating benzothiazole moiety via its reactions with some N-nucleophiles. The newly synthesized compounds were characterized by IR, (1)H NMR and mass spectral studies. Representative compounds of the synthesized products were tested and evaluated as antimicrobial agents. (C) 2009 Elsevier Masson SAS. All rights reserved.