Synthesis of novel urea and thiourea derivatives of diphenylphosphoramidate and their antimicrobial activity

A series of novel urea/thiourea derivatives of diphenylphosphoramidate have been synthesized in two steps. In the first step, 4-aminoaniline/4, 4’diaminodiphenylsulfone (Dapsone) was reacted with diphenyl chlorophosphate in the presence of triethylamine (TEA) to get intermediates. Intermediates further treated with various substituted aromatic isocyanates/ isothiocyanates in the presence of TEA to obtain the title compounds. The structures of newly synthesized compounds were confirmed by IR, NMR (H, C, and P), mass and elemental analysis. The title compounds showed good antibacterial activities against Gram-positive and Gram-negative bacteria.