Phenylselenyl Dutasteride α-Dimer is an intermediate for the synthesis of Dutasteride α-Dimer (D735015), which is a dimer impurity of Dutasteride (D735000); a dual inhibitor of 5α-reductase isoenzymes type 1 and 2. Dutasteride is structurally related to Finasteride (F342000) and is used in the treatment of benign prostatic hyperplasia.