Reaktion #85113

Reaktionsgleichung

pyridinium hydrobromide

4-bromo-2,5-dimethoxypyridine

→

4-Bromo-5-methoxypyridin-2(1H)-one

Lösungsmittel

dimethylformamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   Einengenconcentrated under reduced pressure
2. 2
   SonstigeThe residue was triturated with 50 ml of water
3. 3
   Filtrationfiltered off
4. 4
   Waschenwashed with water
5. 5
   Sonstigedried under reduced pressure
6. 6
   ExtraktionThe filtrate was extracted twice with dichloromethane/methanol (10:1)
7. 7
   TrocknenThe combined organic phases were dried (sodium sulphate)
8. 8
   Filtrationfiltered
9. 9
   Einengenconcentrated under reduced pressure
10. 10
    Sonstigedried

Vorschrift

2.82 g (176 mmol, 20 eq.) of pyridinium hydrobromide were added to a solution of 1.94 g (8.81 mmol) of 4-bromo-2,5-dimethoxypyridine in 80 ml of dimethylformamide, the mixture was stirred at 100° C. for 3 h and concentrated under reduced pressure. The residue was triturated with 50 ml of water, filtered off, washed with water and dried under reduced pressure. The filtrate was extracted twice with dichloromethane/methanol (10:1). The combined organic phases were dried (sodium sulphate), filtered, concentrated under reduced pressure and dried. Yield: 771 mg (43% of theory) and 465 mg (purity 88%, 23% of theory)

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