2-Bromo-4-chlorothieno[3,2-c]pyridine

28948-60-9

28948-61-0

General procedure for the synthesis of 2-bromo-4-chlorothieno[3,2-C]pyridine from 2-bromo-4-hydroxythieno[3,2-C]pyridine: Phosphorus oxychloride (4.08 g, 26.6 mmol) was slowly added dropwise to a mixture of 2-bromothieno[3,2-c]pyridin-4(5H)-one (2.04 g, 8.87 mmol), and the reaction was carried out at 0 °C. Subsequently, the reaction mixture was heated to 135 °C for 2.5 hours. After completion of the reaction, the mixture was carefully poured onto ice water. The precipitate was collected by filtration and dried to afford 1.78 g (80.7% yield) of the target product 2-bromo-4-chlorothieno[3,2-C]pyridine. The product was characterized by 1H NMR (270 MHz, CH3OH-d4): δ 7.67 (d, 1H), 7.88 (dddd, J = 6.33 Hz, 2H), 8.19 (d, J = 5.54 Hz, 1H); the mass spectrometry (MS) showed the molecular ion peak as 248.0 (M-H)+; and the high-performance liquid chromatography (HPLC) analysis showed the purity as 100%.