Synthesis and Antimicrobial Studies of Novel Billogical Heterocycles

The synthetic route of sildenafil promoted us to synthesize new object molecules. New analogues containing a 4‐thiazolidinone ring bonded to the phenyl moiety at the 2‐position, 7‐(substituted anilino)‐6‐fluoro‐2‐(p‐meth‐ oxy‐m‐{[2‐(p‐hydroxyphenyl)‐4‐oxo‐1,3‐thiazolidin‐3‐yl]aminocarbonyl}phenylsulfonamido)benzothiazoles (4a–4l) have been synthesized by cyclization with thioglycollic acid of Schiff bases 3a–3l from corresponding 7‐(substituted anilino)‐6‐fluoro‐2‐(p‐methoxy‐m‐hydrazinocarbonyl phenylsulfonamido)benzothiazoles (2a–2l). Compounds 2a–2l in turn were prepared by dehydroxyhalogenation followed by condensation with hydrazine hydrates of acids 1a–1l. Compounds 1a–1l in turn were prepared by chlorosulfonation of o‐methoxy benzoic acid followed by condensation with 6‐fluoro‐7‐(substituted anilino)‐2‐aminobenzothiazoles. Final compounds have been characterized by their elemental analysis, IR, NMR and mass spectra. All the synthesized compounds have been screened for their antimicrobial activities. Some of them showed good activities.