In this paper we present a detailed study of the bromination reaction of cyclopentadithiophene (CPDT) derivatives, by means of NBS, giving access to either 2, 6- dibromo-4H-cyclopenta [2, 1-b: 3, 4-b′] dithiophenes or 2H-cyclopenta [2, 1-b: 3, 4-b′] dithiophene-2, 6 (4H)-diones (CPDT-2, 6-diones). The CPDT-2, 6-diones are fully characterized, including an X-ray single crystal structure of one of the representative ...