24016-03-3

16867-03-1

100-44-7

24016-03-3

At a temperature lower than 40°C, 48L of deionized water was added to a 300L stainless steel reactor, and 48kg of sodium hydroxide was added under slow stirring until completely dissolved. Subsequently, 16 kg of 2-amino-3-hydroxypyridine, 1.6 kg of tetrabutylammonium bromide, and 17.92 L of benzyl chloride were added sequentially to the sodium hydroxide solution. The reaction mixture was heated to 70~75°C and kept at this temperature for 6 hours. When the reaction was completed, stirring was stopped and the mixture was left to stratify. The aqueous phase was extracted with toluene (20L x 3) and the combined organic phases were washed with pure water (30L x 2). The organic phase was concentrated until a large amount of solid precipitated, followed by crystallization at 0~5°C and stirring for 2 hours. Upon completion of crystallization, centrifugation was performed and the filter cake was washed with 3.2 L of pre-cooled toluene. Finally, it was dried under vacuum at 50~55°C for 3 h to give 22.5 kg of bright yellow solid Intermediate II (2-amino-3-benzyloxypyridine) in 77.3% molar yield and 99.53% purity.