The general procedure for the synthesis of 3,6-bis(5-bromo-2-thienyl)-2,5-bis(2-ethylhexyl)-2,5-bis(2-ethylhexyl)-2,5-dihydropyrrolo[3,4-C]pyrrole-1,4-diones was carried out using 2,5-bis(2-ethylhexyl)-3,6-bis(thiophen-2-yl)pyrrolo[3,4-C]pyrrole-1,4-diones as starting material as follows: in a 100 mL single-necked round-bottomed flask was charged with compound 3 (1.01 g, 2.05 mmol) and 50 mL of CHCl3. The reaction mixture was cooled to 273 K and N-bromosuccinimide (NBS) was added in batches under stirring. After NBS was completely added, the mixture was slowly warmed to room temperature and stirring was continued for 2 hours. Upon completion of the reaction, the mixture was poured into water and extracted with CHCl3. The organic phases were combined and evaporated to remove CHCl3. The resulting red solid was purified by column chromatography using CHCl3/petroleum ether as eluent. The final isolation afforded 0.95 g of the target product 4 in 71% yield. The structure of the product was confirmed by 1H NMR, 13C NMR and FTIR.1H NMR (500 MHz, CDCl3) δ (ppm): 8.30 (d, J = 3.7 Hz, 2H), 6.62 (d, J = 3.7 Hz, 2H), 3.99 (m, 4H), 1.78-1.68 (m, 2H), 1.39-1.24 ( m, 16H), 0.92 (t, J = 7.5 Hz, 6H), 0.88 (t, J = 7.0 Hz, 6H).13C NMR (75 MHz, CDCl3) δ (ppm): 161.1, 146.4, 132.9, 126.4, 122.4, 115.7, 106.4, 46.4, 40.2, 30.7 28.9, 23.9, 23.3, 14.2, 10.8. FTIR (KBr) νmax: 3422, 3084, 2957, 2926, 2859, 1657, 1556, 1504.9, 1450, 1406, 1308, 1261, 1233, 1165, 1100, 1072, 1027, 967, 833, 810, 731. 833, 810, 731, 709, 635, 466, 430 cm-1.
![2,5-bis(2-ethylhexyl)-3,6-di(thiophen-2-yl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione](/CAS/20150408/GIF/1185885-86-2.gif)
![3,6-Bis(5-bromo-2-thienyl)-2,5-bis(2-ethylhexyl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione](/CAS2/GIF/1000623-95-9.gif)