Synthesis, characterization and biological evaluation of quinazoline-4-one derivatives via cyclization of hydrazones

Abstract

This study investigates the synthesis and biological activity of novel quinazoline-4-one derivatives, synthesized through Schiff base reactions involving hydrazine and various substituted benzaldehydes in ethanol. The synthetic route commenced with the reaction of phthalic anhydride with an amino acid, resulting in the formation of an aromatic amino acid. This intermediate underwent esterification with thionyl chloride and ethanol to yield an aromatic ester. The ester was subsequently converted to an aromatic hydrazide by reaction with 80% aqueous hydrazine in ethanol. The hydrazide was then reacted with different aromatic aldehydes in the presence of a small amount of glacial acetic acid to form the corresponding hydrazone derivatives. In the final step, quinazoline-4-one derivatives were synthesized by reacting the hydrazone with anthranilic acid. The structures of the synthesized compounds were characterized using various spectroscopic techniques, including FT-IR, ¹H-NMR, and ¹³C-NMR. The biological activities of these novel derivatives were evaluated, offering insights into their potential applications in medicinal chemistry.