Facile synthesis, spectral characterization and antimicrobial activity of 6-substituted-2,4,8,10-tetra-t-butyl dibenzo[d,g][1,3,6,2]dioxathiaphosphocin 6-oxides

Several novel 2,4,8,10-tetra-t-butyl-6-substituted dibenzo[d,g][1,3,6,2]dioxathiaphosphocin 6-oxides were synthesized in high yield by cyclocondensation of 2,2′-thiobis(2,4-di-t-butylphenol) with phosphorus oxychloride in the presence of triethylamine and a catalytic amount of dimethylaminopyridine (DMAP) in dry toluene followed by in situ reaction with different bulky phenols/thiophenols under the same reaction conditions. The structures of the synthesized compounds were confirmed by analytical, IR, multinuclear NMR studies. Their antibacterial and antifungal activities were evaluated against Staphylococcus aureus, Escherichia coli, Aspergillus niger and Fusarium oxysporium, respectively. Some of them showed moderate activity against these microorganisms.