Synthesis and antibacterial activity of newly synthesized 7-chloro–2–methyl-4h–benzo[d] [1, 3]–oxazin–4–one and 3–amino-7-chloro-2–methyl-quinazolin-4(3h)–one

The current study is aimed at the synthesis of these quinazolinone derivatives 7-Chloro-2-Methyl-4H-benzo[d]-[1,3]-Oxazin-4-one and 3-Amino-7-Chloro-2—Methyl-3H-Quinazolin-4-One and evaluate them for their antibacterial activity.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 7-chloro-2-methyl-4H-benzo[d][1,3]-oxazin-4-one and 3-amino-7-chloro-2-methyl-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 against various strains of microorganism; Klebsiella pneumonia, Staphylococcus aureus, Bacillus species, Escherichia coli, Klebsiella pneumonia, , and Candida albicans. Compounds 1 and 2 showed significant activity against Klebsiella pneumonia, Staphylococcus aureus and Pseudomonas aeruginosa with MIC ranging from 6 – 9 mg/mL. The test investigated compounds exhibited significant antibacterial activity against the bacteria when compared with the control test sample. The IR spectra of compound 1 were characterized by absence of υ NH₂ and presence of υ C-O stretch in 1157 cm^-1 region of the compound. Compound 2 was characterized by absence of υ C-O and presence of υNH₂ in 3285 cm^-1 and 3184 cm^-1 region of the compound. The compounds synthesized exhibited promising antibacterial activities against    Klebsiella pneumonia, Staphylococcus aureus and Pseudomonas aeruginosa, stock cultures. The compounds have high activity against the microorganisms. Compound 2 has a higher activity against Klebsiella pneumonia, Styphylococcus aureus, Pseudomonas aeruginosa, and Bacillus cereus compared to Compound 1.