Synthesis,antibacterial and antifungal activities of new chiral 5-alkyl-3-(1′-benzenesulfonylpyrrolidin-2′-yl)-4,5-dihydro-1,2,4-oxadiazin-6-ones

Chiral α-bromoacid chlorides can be easily prepared from amino acids. Their condensation with new 1-benzenesulfonylpyrrolidin-2-carboxamidoxime derived from proline lead to the corresponding O-(bromoacyl) amidoximes. The latter afforded new chiral 5-alkyl-3-(1′-benzenesulfonylpyrrolidin-2′-yl)-4,5-dihydro-1,2,4oxadiazin-6-ones in good chemical yields via intramolecular cyclization in the presence of one equivalent of NaH. These new compounds were evaluated for their antibacterial and antifungal activities using micro-dilution tests against some strains of bacteria and fungi. Our compounds showed an excellent antibacterial activity, which is better than the drug levofloxacin.