67-56-1

67443-38-3

152684-30-5

Sodium metal (2.90 g, 126.4 mmol) was added to the cooled methanol (50.0 mL) in batches, and the mixture was slowly warmed to room temperature with continuous stirring until the sodium was completely dissolved. Subsequently, the solution was added to 2-chloro-3-nitro-5-bromopyridine (10.0 g, 42.12 mmol, Shanghai Longsheng Chemical, China) suspended in methanol (100 mL) at 0 °C. The reaction mixture was stirred at 0 °C for 1 hour, then warmed up to room temperature and continued stirring for 16 hours. Upon completion of the reaction, the mixture was concentrated to about 80 mL and the reaction was quenched with deionized water (100 mL). The precipitate was collected by filtration, washed with deionized water (50 mL x 2) and dried under an infrared lamp to afford 5-bromo-2-methoxy-3-nitropyridine as a light yellow solid (9.62 g, 98% yield). Mass spectrum (ESI, positive ion mode) m/z: 233.0 [M + H]+.