77618-99-6

35196-09-9

77618-99-6

The general procedure for the synthesis of 2-amino-5-(methylthio)pyridine from 5-(methylthio)-2-nitropyridine was as follows: 5-(methylthio)-2-nitropyridine (300 mg, 1.8 mmol) was dissolved in a mixed solvent of acetic acid (7 mL) and concentrated hydrochloric acid. Concentrated hydrochloric acid (0.5 mL) and zinc powder (692 mg, 10.6 mmol) were slowly added to the reaction system in batches under ice bath cooling for 5 min. Subsequently, the reaction mixture was stirred at room temperature for 30 min. Upon completion of the reaction, the insoluble material was removed by filtration, and the filtrate was neutralized with aqueous sodium bicarbonate to neutral and extracted with dichloromethane. The organic layers were combined, washed sequentially with water and saturated aqueous sodium chloride, and dried over anhydrous sodium sulfate. The solvent was removed by distillation under reduced pressure, and the crude product obtained was purified by silica gel column chromatography (elution gradient: hexane/ethyl acetate=1:1→chloroform/methanol=20:1), and finally 158 mg of 2-amino-5-(methylthio)pyridine (Yield 64%) was obtained as a light-yellow powdery crystal.