反应详情

温度

-5 °C

Hydrobromic acid (48% wt. in water, 120 ml) is added dropwise to a suspension of 3-amino-4′-chloro-4-methylbiphenyl (21 g, 0.09 mol) in water (80 ml), and the mixture stirred until the solid is dissolved. The mixture is cooled to −5° C. and a solution of sodium nitrite (10.12 g, 0.14 mol) in water (50 ml) is added dropwise, maintaining the temperature at 0-5° C. The reaction mixture is stirred for 1 hour, then added to a pre-cooled solution of cuprous bromide (17.9 g, 0.12 mol) in hydrobromic acid (48% wt. in water, 120 ml) at 0° C. The reaction mixture is stirred and allowed to warm to room temperature overnight. The mixture is extracted with ethyl acetate, and the organic extracts are combined, dried over anhydrous sodium sulfate, filtered and the filtrate concentrated in vacuo. The residue is further purified by column chromatography on silica gel, eluting with 2% ethyl acetate in hexane to give 3-bromo-4′-chloro-4-methylbiphenyl (15.0 g).

1. dissolutionis dissolved
2. temperaturemaintaining the temperature at 0-5° C
3. stirringThe reaction mixture is stirred for 1 hour
4. stirringThe reaction mixture is stirred
5. temperatureto warm to room temperature overnight
6. extractionThe mixture is extracted with ethyl acetate
7. dry with materialdried over anhydrous sodium sulfate
8. filtrationfiltered
9. concentrationthe filtrate concentrated in vacuo
10. customThe residue is further purified by column chromatography on silica gel
11. washeluting with 2% ethyl acetate in hexane