Synthesis of new oxadiazole, triazole and oxazepine derivatives of quinazoline moiety

Abstract

New 2-(4-oxo-2-phenylquinazolin-3(4H)-yl)-3-phenyl propanoic acid derivatives have been prepared by reaction of 2-phenyl-4H-1,3-benzoxazin-4-one with phenylalanine. The reaction of compound 1 with thionyl chloride produced 2-[4-oxo-2-phenylquinazolin-3(4H)-yl]-3-phenylpropanoyl chloride (2). Condensation of compound 2 with hydrazine hydrate afforded 2-[4-oxo-2-phenylquinazolin-3(4H)-yl]-3-phenyl propane hydrazide (3). The reaction of compound 3 with carbon disulfide and potassium hydroxide yielded 3-[1-(5-mercapto-1,3,4-oxadiazol-2-yl)-2-phenylethyl]-2-phenylquinazolin-4(3H)-one (4). Teratment of compound 4 with hydrazine hydrate gave 3-[1-(5-mercapto-4H-1,2,4-triazol-3-yl)-2-phenylethyl]-2-phenylquinazolin- 4(3H)-one (5). The reaction of compound 3 with phenyl isothiocyanate resulted in formation of 2-[2-(2-phenyl-4-oxoquinazolin-3(4H)-yl)-3-phenylpropanoyl] hydrazine carbothioamide (6). Treatment of compound 6 with aqueous sodium hydroxide solution produced 3-[1-(5-mercapto-4-phenyl-4H-1,2,4-triazol-3-yl)-2-phenylethyl]2-phenylquinazolin-4(3H)-one (7). The azomethines 8a-d were synthesized from the reaction between the corresponding aldehydes and acid hydrazide 3. Moreover, N-(3-methyl-1,5-dioxobenzo[e][1,3]oxazepin-4(1H,3H,5H)-yl-2-(4-oxo-2-phenyl quinazoline-3(4H)-yl)acetamide 9a-d were synthesized from the cyclic condensation of imines with phthalic anhydride. The structure of novel synthesized compounds were suggested from IR,1H NMR and and13C NMR spectral studies.