Reaction #2146685

Reaction equation

2-bromo-3-methoxy-6-nitropyridine

hydrazine monohydrate

→

2-amino-5-methoxypyridine

Yield 88.3%

Solvents

ethanol

Conditions

Workup

1. 1
   TemperatureAfter the reaction mixture was refluxed for 70 minutes
2. 2
   FiltrationThen, after palladium-carbon was filtered off
3. 3
   Washthe residue was washed with ethanol
4. 4
   ConcentrationThe combined solution was concentrated under reduced pressure
5. 5
   workup.ADDITIONThen, 1300 mL of water and 130 mL of conc. aqueous ammonia were added to the concentrate
6. 6
   Extractionthe resulting mixture was extracted eight times with chloroform
7. 7
   DryingThe combined chloroform layer was dried over anhydrous sodium sulfate
8. 8
   Concentrationconcentrated under reduced pressure
9. 9
   workup.DISTILLATIONThe resulting crude product was distilled under reduced pressure

Procedure

55.6 g (corresponding to 0.239 mol) of 2-bromo-3-methoxy-6-nitropyridine was dissolved in 1700 mL of ethanol, and 37.3 g (50% wet) of 10% palladium-carbon was added thereto under argon stream. To the mixture, 283 mL of hydrazine monohydrate was then added dropwise. After the reaction mixture was refluxed for 70 minutes, the reaction solution was cooled down to room temperature. Then, after palladium-carbon was filtered off, the residue was washed with ethanol, and the washings were combined with the filtrate. The combined solution was concentrated under reduced pressure. Then, 1300 mL of water and 130 mL of conc. aqueous ammonia were added to the concentrate, and the resulting mixture was extracted eight times with chloroform. The combined chloroform layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The resulting crude product was distilled under reduced pressure to obtain 26.2 g (corresponding to 0.211 mol) of 2-amino-5-methoxypyridine (FIG. 2, Step 3).

Source