Synthesis, characterization and antimicrobial activity of new 2-phenylquinoline-4(3H)-one derivatives

Abstract

Quinazolinones is an important chemical synthesis with different physiological significance and pharmacological utility. Reaction of anthranilic acid with benzoyl chloride in pyridine yielded 2-phenyl-4H-benzo[d][1,3]oxazin-4-one, which on condensation reaction with the tryptophan in glacial acetic acid afforded 3-(1H-indol-3-yl)-2-(4-oxo-2-phenylquinazolin-3(4H)-yl) propanoic acid (2). Treatment of compound (2) with thionyl chloride produced 3-(1H-indol-3-yl)-2-(4-oxo-2-phenylquinazolin-3(4H)-yl) propanoyl chloride (3).Condensation of compound (3) with hydrazine hydrate gave 3-(1H-indol-3-yl)-2-(4-oxo-2-phenylquinazolin-3(4H)-yl) propanehydrazide (4). Condensation of compound (4) with ethyl aceto acetate in glacial acetic acid yielded 3-(3-(1H-indol-3-yl)-1-(3-methyl-5-oxo-4,5-dihydro-1H-pyrazol-1-yl)-1-oxopropan-2-yl)-2-phenylquinazolin-4(3H)-one (5). The reaction of compound (4) with carbon disulfide and sodium hydroxide yielded3-(2-(1H-indol-3-yl)-1-(5-mercapto-1,3,4-oxadiazol-2-yl) ethyl)-2-phenylquinazolin-4(3H)-one (6).Condensation of compound (6) with hydrazine hydrate afforded 2-hydrazinyl-5- (2-(1H-indol-3-yl) ethyl)-2-phenylquinazolin-4(3H)-one(7). Compound (8) 2-(3-(1H-indol-3-yl)-2-(4-oxo-2-phenylquinazolin-3(4H)-yl)propanoyl)-2,3-dihydrophthalazine-1,4-dione was synthesized by condensing compound (4) with phthalic anhydride in glacial acetic acid. When compound (4) was reacted with different aromatic aldehydes in abs. ethanol afforded different substituted (9a-d).Moreover, N-(1,5-dioxo-3-substituted-1,5-dihydrobenzo[e][1,3] oxazepin-4(3H)-yl)-3-(1H-indol-3-yl)-2-(4-oxo-2-phenylquinazolin-3(4H)-yl) propanamide (10a,b) were prepared from the cyclic condensation of Schiff bases compounds with phthalic anhydride. The structures of newly synthesized compounds were characterized by m.p., TLC, FTIR and 1H, 13C-NMR spectral analysis. The antimicrobial activity of the synthesized phenylquinazoline on two kinds of bacteria namely, staphylococcus aureous and Escherichia coli was investigated.