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

AbstractBy 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.