In the present study, a series of novel quinazolinone derivatives by the reaction of an anthranillic acid with benzoyl chloride to form the intermediate product of benzoxacin 4 one which is treated with hydrazine hydrate and condensed by 4 chloro- benzaldehyde, 4 chloro- phenyl amino thiadiazole, ketone derivatives, mercaptoacetic acid, and THF. The chemical structures of the synthesized compounds were confirmed by means of IR, H1-NMR and mass spectroscopy. These compounds were screened for anti-inflammatory (Carrageen-Induced Paw Edema), analgesic activity (Eddy’s hot plate method) and anti-bacterial activity (Plate Hole Diffusion Method) against gram +ve and gram –ve bacteria. Compound QD-A and QD-C had given good anti-inflammatory and compound QD-A and QD- B analgesic activity compare to standard. All the synthesized compounds exhibit good antibacterial activity. Compounds QD-A and, QD-B, exhibited good antibacterial activity on Escherichia coli and Bacillus subtilis.