New guanine deaminase inhibitors.

2-Aryl/alkyl-3-(5'-carboxamido-imidazol-4'-yl)-quinazolin-4-(3H)-o nes have been reported as Guanine deaminase inhibitors. These compounds were prepared from 4-amino-5-imidazol-carboxamide and suitable 2-aryl/alkyl-benzoxazin-4-ones. Compounds were characterized by their m.ps., elemental analyses and I. R. spectra. These compounds have shown significant inhibition, aryl substituent was more effective than alkyl group. This is the first report when quinazolones have been reported as Guanine deaminase inhibitors. Inhibitors of this enzyme can enhance the bioavailability of purine antagonists and in turn are helpful for the chemotherapy of cancer.