The current study involves the preparation of number of urea derivatives from reaction of urea or thiourea with aromatic amines as in compounds:"Phenylthiourea, N-phenylurea, N-(2-methoxyphenyl) urea, N-(4-aminophenyl) urea, N-(2-methylphenyl) urea, N-(2-methoxyphenyl) thiourea, N-[4- (amino carbonyl) amino phenyl] urea, N-[4-(amino carbonyl) amino phenyl] acetamide, N-pyrazin-2-ylurea, N-pyridin-2-ylurea, N,N´-bis(3-bromophenyl)urea, N,N´-bis(2-methoxyphenyl)urea ".In addition to the preparation of three compounds considered as Schiff bases that were prepared from reaction of thiosemicarbazide with aldehyde or aromatic ketone as in the compounds:"(N-(4-hydroxybenzylidene) hydrazinecarbothioamide, 2-hydroxybenzaldehydethiosemicarbazone, 1-(4-hydroxyphenyl) ethan-1-onethiosemicarbazone)"The identification of the prepared compounds was done using spectroscopy (FTIR) and purities of the compounds were determined using TLC which was pure and melting points for these compounds were determined in addition to biological activities against Proteus mirabilis were estimated using disc diffusion method around the plate where antibacterial activities estimated. Some of the prepared compounds effects on urease activity were studied and showed good effect in urease inhibition. Some compounds show competitive inhibition and others non-competitive type.And lastly Vmax, Ki, Km, i % values of the enzymes were calculated using line weaver Burck equation.
