Synthesis, characterization and biological evaluation of some heterocyclic compounds containing ethoxyphthalimide moiety via key intermediate 6-chloro 1,3 benzothiazole 2-amine

New and simplc synthetic methods for the synthesis of ethyl 8-chloro-4(4-substitutedphenyl)-2-[(N-ethoxyphthalimido)amino]-4H-pyrimido]2,1-b][1,3]benzothiazole-3-carboxylate 5a-d and 6-chloro-N-[3-{2-(4-substitutedphenyl)ethenyl}-1-N-ethoxyphthalimidoquinoxalin-2(1H)-ylidene]-1,3-benzothiazol-2-amine 10a-d arc described. 4-Chloroaniline I is converted to 6-chloro-1,3-benzothiazol-2-amine 2 by reaction with KSCN and Br 2 . Compound 2 acts as key intermediate for both the series of final compounds. In one pathway, 2 is converted to corresponding pyrimidothiazoles 4a-d by treatment with ethyl arylidinecyanoacetate 3a-d, which on condensation with phthalimidoxyethyl bromide 6 gives 5a-d. In a parallel route. reaction of 2 with 3-[2-(4-substituted phenyl)ethenyl]lquinoxalin-2(1H)-one 8a-d affords 6-chloro-N-[3-(2-(4-substituted phenyl)ethenyl}quinoxalin-2(1H)-ylidene]-1,3-benzothiazol-2-amine 9a-d which on condensation with phthalimidoxyethyl bromide 6. yields final compound 10a-d. Structure elucidation is accomplished by elemental analysis and spcctral data of the synthesized compounds. Final compounds 5a-d and 10a-d have been screened in vitro for their antimicrobial activity against different strains of bacteria and fungi.