Microwave-ultrasonic assisted synthesis, and characterization of novel 3′-(amino, hydrazino and hydrazide)-6′-bromo-spiro(isobenzofuran-1,2′-quinazoline)-3,4′-dione derivatives as antimicrobial agents

Abstract

By attempts to construct new antimicrobial agents, a series of mono-and dibromo of 3′-(oxiranyl, hydrazide, oxadiazolo and pyrazolo)-methylene-spiro[isobenzofuran-1,2′-quinazoline]-3,4′(3′H)-dione derivatives were synthesized through the interaction between 6-bromo and/or 6,8-dibromo-spiroiso-benzofuran-1,2′-quinazolindione with carbon electrophiles, namely, ethyl chloroacetate, epichlorohydrin, chloroacetyl chloride and phosphorus pentasulfide (P2S5). Reaction of ethylester of spiroquinazolindione with hydrazine hydrate under MW-US and UV reaction condition (green tool saves time and energy) to afford spiroquinazolindione hydrazide that used as preparatory materials for the synthesis of novel spiroquinazolin-dione. Most of the created compounds were evaluated in vitro for their antibacterial and antifungal activity. The 6-bromo or 6,8-dibromo quinazolin-3,4-dione nucleus bears oxirane hydrazino acetyl, hydrazide, oxadiazole and pyrazole moieties at position (3) and were the most potent against the gram-positive bacteria, gram-negative bacteria, and fungi comparable to Chloramphenicol and Fluconazole.