3-Substituted derivatives [IV-a-d, V-a-d, VI-a-c and VII-a-c] of 4-Cyano-5-imino-3-methylthio-9-nitro-2H-1,2,4- triazipino [3,4-b] [1,3] benzothiazole have been prepared through One Step Multicomponent reaction by heating a mixture of 2-hydrazino-6-nitro benzothiazole (I) and bis methylthio methylene malononitrile (II) independently with aromatic amines / phenols / heterylamines / compounds containing active methylene group respectively in the presence of dimethyl formamide and catalytic amount of anhydrous potassium carbonate. All these newly synthesized compounds were screened for antibacterial activity.