937012-11-8

101083-92-5

To a stirred suspension of 5-nitro-1-(phenylsulfonyl)-1H-pyrrolo[2,3-b]pyridine (10.2 g, 33 mmol) in methanol (250 mL) was added powdered sodium hydroxide (2 g, 50 mmol) in batches. After stirring the reaction mixture for 30 min at room temperature, powdered sodium hydroxide (2 g, 50 mmol) and dichloromethane (50 mL) were added again and stirring was continued for 30 min. Upon completion of the reaction, the mixture was concentrated, followed by the addition of a mixed solution of 2N HCl (50 mL) and water (200 mL), and the resulting mixture was filtered. The yellow filter cake was washed with water and dried to afford 5-nitro-1H-pyrrolo[2,3-b]pyridine (4.6 g, 28.2 mmol, 85% yield). The product was characterized by 1H-NMR (DMSO-d6) with the following chemical shift δ (ppm): 6.78 (dd, J = 3.50, 1.83 Hz, 1H), 7.79 (dd, J = 3.35, 2.59 Hz, 1H), 8.90-8.92 (m, 1H), 9.13 (d, J = 2.59 Hz, 1H), 12.05- 12.92 (m, 1H).