Synthesis of Novel pyrimido[4,5-b]quinoline-4-one Derivatives and Assessment as Antimicrobial and Antioxidant Agents

Objective: Antimicrobial resistance has emerged as one of the serious global health problems of the 21^st century that threatens the efficient treatment and prevention of an everincreasing range of infections caused by bacteria, viruses, and fungi. Therefore, it would be favorable to find promising agents with antioxidant and antimicrobial activity combined in one molecule. Key findings: Pyrimido[4,5-b] quinolines are biologically active compounds that are known to rely primarily on the functional group’s existence and location. Quinolinbenzo-[ 1,3]oxazin-4-one (3) was prepared and played as electrophilic interface/mediator for the synthesis of many compounds, such as pyrimido[4,5-b]quinoline, quinoline-carboxamide and oxoquinazolin-acetamide by reacting with nucleophilic reagent. Summary: Results revealed that pyrimido[4,5-b] quinoline derivatives (17b, 9d and 9c) are the most potent compounds that displayed significant antimicrobial activity along with compounds 17a, 29b, 5, 19, 23b, and 25b that appeared to be more promising as antioxidant agents than ascorbic acid.