1,5-Dichloropentane is primarily used as an intermediate in organic synthesis for the production of pharmaceuticals, agrochemicals, and other fine chemicals. It serves as a building block in the synthesis of polymers, such as polyurethanes via diisocyanate intermediates, and in the preparation of cyclic compounds like crown ethers. Its role in research and development includes facilitating nucleophilic substitution reactions and creating novel chemical entities. While it can be used in some solvent applications, its main value lies in its reactivity as a reagent.