Synthesis and Antimicrobial Evaluation of Some Novel Pyrido[3,2-F][1,2,3]thiadiazaphosphepinone Compounds, Bearing a Pyridine Moiety

Several pyridothiadiazaphosphepinones (3–9) were synthasized by combining tetraphosphorus decasulfide, Lawesson's reagent, phosphorus tribromide, and P,P-dichlorophenyl phosphine with 2-(aminosulfanyl)-6-(3,4-dichlorophenyl)-4-(furan-2-yl)-5-oxo-5,6-dihydropyridine-3-carbonitrile (2). The reaction mechanisms for these products were discussed. On the basis of elemental analysis and spectrum data, the structures of the newly synthesized compounds were determined. The biological activity of every synthesized compound was examined against various microorganisms using the disc diffusion method. The bulk of the microorganisms tested are effectively inhibited by the newly synthesized chemicals.