Synthesis and antibacterial activities of quinazolin-4(3h)-one, 2-methyl-4(3h)-quinazolinone and 2–phenyl-4(3h)-quinazolinone

Background: Quinazoline and quinazolinone scaffolds represent an important class of biologically active nitrogen heterocyclic compounds. Many marketed drugs are based on these moieties. A diverse range of molecules with quinazoline/quinazolinone moieties have been reported to exhibit broad spectrum of biological activities Objective: This 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 antibacterial activities. Method: The consolidation of 2-amino-methyl-4-methoxybenzoate with acetic anhydride produced the cyclic compound 2-methyl-4, 5-disubstituted-1, 3-benzo-oxazine-4-one which also 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 assuredly validated by means of Infrared, Nuclear Magnetic Resonance (1H and 13C), Gas Chromatography Mass Spectrophotometer and Elemental analysis. The synthesized compounds were tested for their antibacterial activity.Compounds 1,2 and 3 showed significant antibacterial activities. Discussion: Compound 1 was identified by the absence of methyl group and the presence of methyl group for compound 2. The test analysed compounds exhibited significant antibacterial activities. The compounds synthesized exhibited promising antibacterial activities against the tested organisms. Conclusion: The compounds have high antibacterial activities. Compound 2 has a higher activity compared to Compound 1 and 3. Compound 2 has a higher antibacterial against Escherichia coli, Klebsiella pneumonia and Pseudomonas aeuriginosa