Abstract
Novel 6‐substituted 2,10‐dichloro‐4,8‐dinitrodibenzo[d,g][1,3,6,2]dioxathiaphosphocin‐6‐oxides 4 were synthesized by reacting 5,5′‐dichloro‐3,3′‐dinitro‐2,2′‐dihydroxydiphenyl sulfide (2) with different aryl phosphorodichloridates, trichloromethylphosphonic dichloride and O‐2‐chloroethyl phosphoryldichloride (3) in the presence of triethylamine at 55–60°. Some of these compounds are prepared by reacting the monochloride, 2,6,10‐trichloro‐4,8‐dinitrodibenzo[d,g][1,3,6,2]dioxathiaphosphoein‐6‐oxide (5) in situ with substituted phenols and thiols. 5 is prepared by condensing 2 with phosphorus oxychloride. The ^1^H nmr chemical shifts of the dibenzodioxathiaphosphocin moiety indicates the presence of more than one conformer in solution. However the presence of more than one conformer in each example cannot be entirely eliminated. Interestingly 4d on oxidation to 12‐sulphone by H~2~O~2~ in acetic acid medium yielded only 12‐sulphoxide 6a. The ir, ^1^H, ^13^C, ^31^P nmr and mass spectral data are discussed. Some of these compounds were screened for antifungal activity against Curvularia lunata and Aspergillus niger and antibacterial activity on Bacillus subtilis and Klebsiella pneumoniae. A few of them possess significant activity.