Reaktion #43400

Reaktionsgleichung

3-chloro-6-(methyloxy)-1,5-naphthyridin-4(1H)-one

3-chloro-6-(methoxy)-1,5-naphthyridin-4-ol

water

potassium carbonate

phosphorous tribromide

→

desired compound

Ausbeute 91.0%

8-Bromo-7-chloro-2-(methyloxy)-1,5-naphthyridine

Ausbeute 91.0%

Lösungsmittel

N,N-dimethylformamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeat 0° C.
2. 2
   workup.WAITat 25° C. for 1 hour
3. 3
   SonstigeThe solid formed
4. 4
   Filtrationwas filtered off
5. 5
   Waschenwashed with water
6. 6
   Sonstigedried in vacuo

Vorschrift

To a solution of 3-chloro-6-(methyloxy)-1,5-naphthyridin-4(1H)-one (3-chloro-6-(methoxy)-1,5-naphthyridin-4-ol, for a synthesis see WO2004058144, Example 1(a)) (43 g, 204.8 mmol) in N,N-dimethylformamide (500 ml) at 0° C. was added phosphorous tribromide dropwise (23.3 ml, 245.8 mmol). The reaction mixture was then stirred at 10° C. for 0.5 hour and then at 25° C. for 1 hour. The mixture was then poured onto 1600 ml of water and basified to pH 7 with potassium carbonate. The solid formed was filtered off, washed with water and dried in vacuo to afford the desired compound (51 g, 91%).

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