Organoiodine(III) mediated synthesis of 3,9-diaryl- and 3,9-difuryl-bis-1,2,4-triazolo[4,3-a][4,3-c]pyrimidines as antibacterial agents.

Nine 3,9-diaryl- and 3,9-difuryl-bis-1,2,4-triazolo[4,3-a][4,3-c]pyrimidines (3a-i) have been synthesized by the oxidation of bis-2,4-pyrimidinylhydrazones of various araldehydes and furfural with 2equiv of iodobenzene diacetate (IBD) in dichloromethane and tested in vitro for their antibacterial activity. Three compounds, namely 3,9-di-(4'-fluorophenyl)-bis-1,2,4-triazolo[4,3-a][4,3-c]pyrimidine (3f), 3,9-di-(4'-nitrophenyl)-bis-1,2,4-triazolo[4,3-a][4,3-c]pyrimidine (3g) and 3,9-di-(5'-nitro-2'-furyl)-bis-1,2,4-triazolo[4,3-a][4,3-c]pyrimidine (3i), were associated with substantially higher antibacterial activity than some commercial antibiotics against Gram-positive bacteria namely Staphylococcus aureus, Staphylococcus epidermidis and Bacillus subtilis; two Gram-negative bacteria namely Salmonella typhi and Escherichia coli at MIC (minimum inhibitory concentration) 10microg/ml.