Synthesis and antimicrobial activity of 2‐substituted‐2,3‐dihydro‐5‐propoxy‐1H‐1,3,2‐benzodiazaphosphole 2‐Oxides

Several 2‐alkylcarbamato/thiocarbamato/aryloxy/trichloromethyl‐2,3‐dihydro‐5‐propoxy‐1H‐1,3,2‐benzodiazaphosphole 2‐oxides ( 4 and 6 ) were synthesised by reacting 4‐propoxy‐o‐phenylenediamine ( 1 ) with various N‐dichlorophosphinyl carbamates ( 3 ), aryl phosphorodichloridates ( 5a‐f ) and trichloromethyl phosphonic dichloride ( 5g ) in the presence of triethylamine at 45‐65 °C. Their ir, ¹H, ¹³C, ³¹P nmr and mass spectral data are discussed. The compounds were screened for antifungal activity against Curvularia lunata and Aspergillus niger and for antibacterial activity against Bacillus subtilis and Escherichia coli. Most of these compounds exhibited moderate activity in the assays.