反应详情

温度

0 °C

Slurry 2-amino-4-chlorobenzothiazole (0.255mol) in water (325 mL), heat to reflux and add 48% hydrobromic acid (130 mL). Maintain at reflux for 20 minutes, cool to 0° C. and add a solution of sodium nitrite (17.56g, 0.255mol) in water (90mL), maintaining a temperature of 0° C. Stir at 0° C. for 15 minutes and add by dropwise addition (while keeping cold) to a rapidly stirring mixture of copper (I) bromide (42.03g, 0.293mol) in 48% hydrobromic acid (86mL) and water (225mL). Stir at room temperature for 20 minutes and then heat on a steam bath for an additional 20 minutes. Allow to stand overnight, extract into methylene chloride and dry (MgSO4). Evaporate the solvent in vacuo and purify by chromatography to give 2-bromo-4-chlorobenzothiazole.

1. temperatureto reflux
2. temperatureMaintain
3. temperatureat reflux for 20 minutes
4. temperaturemaintaining a temperature of 0° C
5. additionadd by dropwise addition (while keeping cold) to
6. stirringa rapidly stirring
7. stirringStir at room temperature for 20 minutes
8. temperatureheat on a steam bath for an additional 20 minutes
9. waitAllow to stand overnight
10. extractionextract into methylene chloride
11. dry with materialdry (MgSO4)
12. customEvaporate the solvent in vacuo
13. custompurify by chromatography