Reaktion #159477

Reaktionsgleichung

hydrobromic acid

4′-Chloro-3-methylbiphen-4-ylamine

acetonitrile

butyl nitrite

→

4-bromo-4′-chloro-3-methylbiphenyl

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe reaction mixture is cooled to between −5° C. and 0° C.
2. 2
   Temperaturthe reaction mixture is maintained at between −5 and 0° C. for 30-40 minutes
3. 3
   workup.STIRRINGstirred at 50° C. for 10-15 minutes
4. 4
   TemperaturThe reaction mixture is cooled to room temperature
5. 5
   workup.ADDITIONpoured into ice-cold water
6. 6
   Extraktionextracted with ethyl acetate (3×300 ml)
7. 7
   WaschenThe organic extracts are washed with water
8. 8
   Trocknendried over anhydrous sodium sulfate
9. 9
   Einengenconcentrated under reduced pressure
10. 10
    SonstigeThe residue is purified by column chromatography on silica gel

Vorschrift

4′-Chloro-3-methylbiphen-4-ylamine (16.5 g, 0.077 mol) is added to acetonitrile (140 ml) and stirred at room temperature until dissolution is complete. The reaction mixture is cooled to between −5° C. and 0° C., tent-butyl nitrite (90%, 12.4 ml, 0.093 mol) is added dropwise and the reaction mixture is maintained at between −5 and 0° C. for 30-40 minutes. The mixture is added slowly to the preheated (50° C.) suspension of copper (I) bromide (5.8 g, 0.04 mol) in hydrobromic acid (5.8 ml) and stirred at 50° C. for 10-15 minutes. The reaction mixture is cooled to room temperature, then poured into ice-cold water and extracted with ethyl acetate (3×300 ml). The organic extracts are washed with water, dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue is purified by column chromatography on silica gel to yield 4-bromo-4′-chloro-3-methylbiphenyl (11.5 g).

Quelle