Synthesis and urease inhibition studies of some new quinazolinones

In this study, novel quinazolinones were designed, synthesized, characterized by FT‐IR, 1 H‐NMR, 13 C‐NMR spectral data, and LC–MS. New compounds inhibitory activities on urease were assessed. All of the compounds exhibited potent urease inhibitory activities. Especially in the synthesized compounds, 2‐benzyl‐3‐({5‐[(4‐nitrophenyl)amino]‐1,3,4‐thiadiazol2‐yl}methyl)quinazolin‐4(3 H )‐one has the best inhibitory effect against Jack bean urease with IC 50 = 3.30 ± 0.09 μg/mL. And also, N ‐(4‐nitrophenyl)‐2‐[(4‐oxoquinazolin‐3(4 H )‐yl)acetyl] hydrazinecarbothioamide, N ‐(4‐fluorophenyl)‐2‐[(4‐oxoquinazolin‐3(4 H )‐yl)acetyl] hydrazinecarbothioamide, and 2‐benzyl‐3‐({5‐[(4‐fluorophenyl)amino]‐1,3,4‐thiadiazol‐2yl} methyl)quinazolin‐4(3 H )‐one have best activities among the synthesized compounds.