Reaktion #161777

Reaktionsgleichung

sodium hydroxide

phosphorus oxychloride

5-bromo-2-methyl-4-nitropyridine-1-oxide

→

5-bromo-4-chloro-2-methylpyridine-1-oxide

Lösungsmittel

DCM

DCM

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe reaction mixture was then refluxed for 5 h
2. 2
   SonstigeThe organic phase was separated off
3. 3
   Extraktionthe aqueous phase was extracted twice more with DCM
4. 4
   SonstigeThe combined organic phases were dried on sodium sulphate
5. 5
   Sonstigeevaporated down
6. 6
   Sonstigethe precipitate formed
7. 7
   Filtrationfiltered
8. 8
   Sonstigedried

Vorschrift

4.2 mL (46 mmol) phosphorus oxychloride in 20 mL DCM were added dropwise at 10° C. to 3.6 g (15 mmol) 5-bromo-2-methyl-4-nitropyridine-1-oxide in 30 mL DCM. The reaction mixture was then refluxed for 5 h, then added to ice water and adjusted to a pH of 10 with 4N aqueous sodium hydroxide solution. The organic phase was separated off and the aqueous phase was extracted twice more with DCM. The combined organic phases were dried on sodium sulphate and evaporated down. The residue was stirred into petroleum ether, the precipitate formed was suction filtered and dried.

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