Synthesis And Anagesic activities of Quinazolin-4(3H)-One, 2-Methyl-4(3H)-Quinazolinone and 2–Phenyl-4(3H)-quinazolin-4(3H)–one

Background: Objective: The current study is aimed at the synthesis of these quinazolinone derivatives quinazolin-4(3H)-One, 2-Methyl-4(3H)-quinazolinone and 2–Phenyl-4(3H)-quinazolin-4(3H)–one and evaluate them for their analgesic activity. Method: The condensation of 2-amino-methyl-4-methoxybenzoate with acetic anhydride yielded the cyclic compound 2-methyl-4, 5-disubstituted-1, 3-benzo-oxazine-4-one which further produce a novel 2,3-disubstituted quinazolin-4 ones via the reaction with hydrazine hydrate The quinazolinone derivatives quinazolin-4(3H)-One, 2-Methyl-4(3H)-quinazolinone and 2–Phenyl-4(3H)-quinazolin-4(3H)–one were evaluated pharmacologically for their in vivo analgesic activities by acetic acid induced writhing in mice. The compounds synthesized were unequivocally confirmed by means of Infrared, Nuclear Magnetic Resonance (1H and 13C), Gas Chromatography Mass Spectrophotometer and Elemental analysis.The synthesized compounds were screened for their analgesic activity.Compounds 1,2 and 3 showed significant analgesic activity. Discussion: Compound 1 was characterized by the absence of methyl group and the presence of methyl group for compound 2. The test investigated compounds exhibited significant analgesic activity when compared with the control test sample. The compounds synthesized exhibited promising analgesic activities against . Conclusion: The compounds have high analgesic activity. Compound 3 has a higher activity compared to Compound 2 and compound 2 has a higher analgesic activity compared to compound 1. Compound 3 has a higher analgesic activity compared to the standard drugs Aspirin and Indomethacin. Keywords: quinazolin-4(3H)-One, 2-Methyl-4(3H)-quinazolinone and 2–Phenyl-4(3H)-quinazolin-4(3H)–one quinazolin-4(3H)-one, analgesic activity.