Synthesis and antibacterial activity of 5-aryl-2-[(alpha-chloro-alpha-phenylacetyl/alpha-bromopropionyl)amino]- 1,3,4-oxadiazoles and 2-[(5-aryl-1,3,4-oxadiazol-2-yl)imino]-5-phenyl/methyl-4-thiazolidinone s.

Reaction of 5-aryl-2-amino-1,3,4-oxadiazoles (BI-VI), obtained by the oxydative cyclization of aromatic aldehyde semicarbazones (AI-VI), with alpha-chloro-alpha-phenylacetyl chloride and alpha-bromopropionyl bromide yielded 5-aryl-2-[(alpha-chloro-alpha-phenylacetyl)amino]-1,3,4-oxadiazoles (Ia-VIa) and 5-aryl-2-[(alpha-bromopropionyl)amino]-1,3,4-oxadiazoles (VIIa-XIIa), respectively. Furthermore, Ia-XIIa were refluxed with ammonium thiocyanate to give 5-phenyl/methyl-2-[(5-aryl-1,3,4-oxadiazol-2-yl)imino]-4-thiazo lidinones (It-XIIt). All compounds were tested for antibacterial activity against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa.

Synthesis and antimicrobial properties of new 4-(alkylidene/arylidene)- amino-5-(2-furanyl)-2,4-dihydro-3H-1,2,4-triazole-3-thiones and 6-aryl-3-(2-furanyl)-7H-1,2,4-triazolo[3,4-b][1,3,4]thiadiazines.

A series of 4-(alkylidene/arylidene)amino-5-(2-furanyl)-2,4-dihydro- 3H-1,2,4-triazole-3-thiones (2) and 6-aryl-3-(2-furanyl)-7H-1,2,4-triazolo[3,4-b][1,3,4]thiadiazines (3) were synthesized. The configuration of 2g was assigned on the basis of 1H-NMR data. Of the new derivatives tested, only 2b, 2g, and 4f were found to be active against Staphylococcus aureus and/or Staphylococcus epidermidis (MIC 125-1.