4-Chloroquinoline-3-carbaldehyde is primarily utilized in organic synthesis as a key intermediate for the preparation of various biologically active compounds. It serves as a building block in the development of pharmaceutical agents, particularly in the synthesis of antimalarial and anticancer drugs. Its structure allows for further functionalization, making it valuable in creating diverse quinoline derivatives with potential therapeutic applications. Additionally, it is used in research to explore new chemical entities for drug discovery and to study structure-activity relationships in medicinal chemistry.