Synthesis and antimicrobial evaluation of novel urea derivatives from chromene based oxadiazole amines

A series of novel aryl ureides were synthesized based on oxadiazoles and different substituted aromatic amines. The intermediate amine, (3-( 2H -chromen-3-yl)-1,2,4-oxadiazol-5-yl)methanamines ( 6a ) was reacted with aromatic amines in presence of triphosgene to obtain the urea derivatives 7a – d and 7e – i in high yields. The structures of all the intermediates and the final urea derivatives were established by IR, NMR and mass spectrometry data. The antibacterial activity of synthesized compounds was evaluated against two gram-negative bacteria namely Escherichia coli and Pseudomonas aeroginosa and it was observed that the urea derivatives 7a and 7i were promising antibacterial agents.