The general procedure for the synthesis of 3,6-dibromothieno[3,2-b]thiophene from tetrabromothieno[3,2-B]thiophene was carried out as follows: tetrabromothieno[3,2-B]thiophene (9.12 g, 20 mmol), acetic acid (500 ml), and toluene (200 ml) were added to the reactor, followed by zinc powder (2.62 g, 40 mmol). The reaction mixture was filtered and the filtrate was concentrated to give the intermediate 3,6-dibromothieno[3,2-b]thiophene (5.36 g, 90% yield). After completion of the reaction, the synthesis of intermediate C-28-2 was carried out.