Desethyl chloroquine is primarily used in medical research and pharmacology as a metabolite of chloroquine, a well-known antimalarial drug. Its applications include studying the pharmacokinetics and metabolism of chloroquine, helping researchers understand how the drug is processed in the body. It is also utilized in the development and testing of new antimalarial therapies, as its presence and behavior provide insights into the efficacy and safety of related compounds. Additionally, desethyl chloroquine is employed in toxicological studies to assess the potential side effects and long-term impacts of chloroquine use. Its role in these areas contributes to advancements in malaria treatment and the optimization of therapeutic strategies.