Synthesis and Microbial Studies of New Pyridine Derivatives-III

2-Amino substituted benzothiazole 4a—4l and p-acetamidobenzenesulfonyl chloride 2 were used to prepare 2-(p-aminophenylsulfonamido) substituted benzothiazole 6a—6l using mixture of pyridine and acetic anhydride which formed an electrophilic complex (N-acetyl pyridinium) to facilitate condensation to give desired product by removal of HCl. 2-{p-(3-Carboxypyrid-2-yl)amino]phenylsulfonamido}benzothiazoles 8a—8l were synthesized from 2-chloropyridine-3-carboxylic acid 7 and 6a—6l in 2-ethoxy ethanol using Cu-powder and K₂CO₃. Acid chlorides 9a—9l were condensed with 2-hydroxyethyl piperazine 10 and 2,3-dichloropiperazine 11 for amide derivatives 2-(p-((3-(4-(2-hydroxyethyl)piperazin-1-ylcarbonyl)pyrid-2-yl)amino)phenylsulfonamido)benzothiazoles 12a—12l and 2-{p-3-(2,3-dichloropiperazin-1-ylcarbonyl)pyrid-2-ylamino]phenylsulfonamido}benzothiazoles 13a—13l respectively. The structures of the new compounds have been established on the basis of their chemical analysis and spectral data (IR, ¹H NMR and mass). All the compounds have been screened for their antibacterial and antifungal activities.