The current study is aimed at the synthesis and Analgesic evaluation of quinazolinone derivatives. The condensation of Methyl-2-amino-5-bromobenzoate with acetic anhydride yielded the cyclic compound 2-methyl 6-bromo-1, 3-benzo-oxazine-4-one which further produce 3-Amino-2-Methyl 6-bromoquinazolin4(3H)-ones via the reaction with hydrazine hydrate. The compounds synthesized were unequivocally confirmed by means of Chromatography Mass Spectrophotometer and Elemental analysis.  The quinazolonones were evaluated pharmacologically for their in-vivo analgesic activities by acetic acid induced writhing in mice. The two investigated compounds exhibited significant analgesic activity in the range of 74.67 - 83.80% in compared to control.