Synthesis and antimicrobial activity of novel 2-(heteryl-carboxamido)-2,3-dihydro-1H-1,2,5-oxadiazolo[3,4-c][1,3,2]diazaphosphole-2-oxides

Some novel 2-(heterylcarboxamido)-2,3-dihydro-1H-1,2,5-oxadiazolo[3,4-c][1,3,2]diazaphosphole- 2-oxides (4-13) have been synthesized from reaction of 3,4-diamino-1,2,5-oxadiazole (3) with various dichlorophosphinylcarboxamides (2), which were prepared by C-acylation of electron-rich heterocyclic compounds with dichloro isocyanato phosphine oxide (Kirsanov isocyanate) (1) in dry octane, in the presence of triethylamine at 50-60 degrees C. Their structures were determined by IR, H-1, C-13, P-31 NMR and mass spectral ( MS) studies. They were screened for antifungal and antibacterial activity against Curvularia lunata / Aspergillus niger and Staphylococcus aureus / Escherichia coli, respectively. Most of these compounds exhibited moderate activity in the assays.