4-Chloroacridin-9(10H)-one is primarily utilized in the field of organic synthesis and pharmaceutical research. It serves as a key intermediate in the preparation of various acridine derivatives, which are known for their biological activities. This compound is particularly significant in the development of potential therapeutic agents, including anticancer and antimicrobial drugs. Its structure allows for modifications that can enhance the efficacy and specificity of these drugs. Additionally, it is used in the study of fluorescence properties, contributing to the development of fluorescent probes and markers in biochemical research. The compound's ability to interact with DNA also makes it valuable in the investigation of DNA-binding mechanisms and the design of DNA-targeting drugs.