69627-03-8

69627-02-7

69627-03-8

To a 250 mL round-bottomed flask were added 30 mL of methylene chloride and 20 mL of ethylene chloride, followed by N,N-dimethylformamide (1.8 mL, 23.28 mmol) and oxalyl chloride (2.9 mL, 33.86 mmol). Oxalyl chloride was slowly added dropwise to the mixture at 0 °C. Next, thieno[3,2-b]pyridin-7(4H)-one (1.6 g, 10.58 mmol) was added and the reaction mixture was heated to reflux for 6 hours. After completion of the reaction, the mixture was cooled to room temperature to afford 7-chlorothieno[3,2-b]pyridine (1.7 g, 90% yield) as a pale yellow solid. The product was characterized by 1H-NMR (400 MHz, CDCl3): δ 8.61 (d, J = 5.2 Hz, 1H), 7.81 (d, J = 5.2 Hz, 1H), 7.30 (d, J = 4.8 Hz, 1H).