1-Chloro-1-cyclopentene is primarily used as an intermediate in organic synthesis. It serves as a key building block in the production of various pharmaceuticals and agrochemicals. Its structure allows for further functionalization, making it valuable in the development of complex molecules. Additionally, it is employed in research and development for studying reaction mechanisms and creating specialized compounds. Its reactivity with nucleophiles and electrophiles makes it a versatile reagent in synthetic chemistry.