Novel quinazolinone derivatives: synthesis and antimicrobial activity

4-(4-Oxo-4H-3,1-benzoxazin-2-yl)phenyl-4-methylbenzenesulfonate (2) was prepared and reacted with some primary aromatic amines, e.g., aniline, p-chloro aniline, p-methoxy aniline, p-amino benzoic acid and p-amino acetophenone. It reacted also with some heterocyclic amines, e.g., 2-aminothiazole, 2-aminobenzothiazole, 5-amino-4-phenylazo-2,4-dihydropyrazol-3-one and 3-amino-2-methylquinazolinone and with diamines; e.g., o-phenylenediamine, p-phenylenediamine, ethylenediamine, semicarbazide hydrochloride and thiosemicarbazide under different conditions. On the other hand, compound (2) reacted with both sodium azide and active methylene compounds, e.g., ethylcyanoacetate and ethylacetoacetate to give (19) and (20), respectively. All new prepared compounds were subjected to antimicrobial activity evaluation.