Reaction #2146690

Reaction equation

2-bromo-3-methoxy-6-nitropyridine

hydrazine monohydrate

→

2-amino-5-methoxypyridine

Yield 88.0%

Solvents

ethanol

Conditions

Workup

1. 1
   TemperatureAfter the reaction mixture was refluxed for 45 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, 402 mL of water and 38 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

17.36 g (corresponding to 74.50 mmol) of 2-bromo-3-methoxy-6-nitropyridine was dissolved in 520 mL of ethanol, and 11.63 g (50% wet) of 10% palladium-carbon was added thereto under argon stream. To the mixture, 88.4 mL of hydrazine monohydrate was added dropwise. After the reaction mixture was refluxed for 45 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, 402 mL of water and 38 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 8.14 g (corresponding to 65.57 mmol) of 2-amino-5-methoxypyridine (FIG. 3, Step 3).

Source