Thalidomide-5,6-Cl is a chlorinated derivative of thalidomide, primarily utilized in medicinal chemistry and pharmaceutical research. It is studied for its potential therapeutic effects, particularly in the treatment of certain cancers such as multiple myeloma and inflammatory conditions. Its mechanism of action involves modulation of the immune system, inhibition of angiogenesis to target tumors by limiting abnormal blood vessel growth, and regulation of cytokine production, which may benefit autoimmune disorders. As a research compound, it is not approved for clinical use, and ongoing studies explore its derivatives to improve efficacy and minimize side effects.