反应详情

温度

2.5 °C

2-Chloro-pyridin-4-ylamine, (2 g, 15.6 mmol), was dissolved in 20 mL 1M HCl and 4 mL conc. HCl and cooled to 0° C. Sodium nitrite, (1 g, 17 mmol), was dissolved in 2 mL water and added dropwise to the pyridine solution. The mixture was stirred at 0-5° C. for 2 h and then added dropwise to a suspension of SnCl2 in 35 mL conc.HCl at 0° C. The mixture was stirred at 0° C. for 1 h and then the pH carefully raised to pH9-10 with NaOH, using efficient cooling and stirring. The aqueous mixture was extracted with 10% MeOH/chloroform and the organic layer was separated, dried (sodium sulfate), and evaporated. The crude product mixture was purified by column chromatography, (silica, 5% MeOH/DCM), affording 400 mg (2-Chloro-pyridin-4-yl)-hydrazine. MS ES+ 144.0, 146.3

1. customat 0° C
2. stirringThe mixture was stirred at 0° C. for 1 h
3. temperatureusing efficient cooling
4. stirringstirring
5. extractionThe aqueous mixture was extracted with 10% MeOH/chloroform
6. customthe organic layer was separated
7. dry with materialdried (sodium sulfate)
8. customevaporated
9. customThe crude product mixture was purified by column chromatography, (silica, 5% MeOH/DCM),