反应详情

A suspension of 2-methyl-5-nitrobenzotrifluoride (3.90 g, 19 mmol), N-bromosuccinimide (NBS, 3.56 g, 20 mmol), and 2,2′-azobis(2-methylpropionitrile) (AIBN, 0.094 g, 0.6 mmol) in 40 mL of CCl4 was heated at reflux under N2 for 16 h. HPLC indicated ca. 50% conversion. Additional NBS (10 mmol) and AIBN (0.6 mmol) were added and the mixture was heated at reflux for another 14 h. HPLC indicated ca. 80% conversion. The reaction mixture was cooled to ambient temperature, and the solid was filtered and washed with EtOAc. The combined filtrate was washed with aq. NaHCO3, dried over Na2SO4, filtered, concentrated on rotovap, and further dried under vacuum. 1H NMR indicated the ratio of desired product to unreacted 2-methyl-5-nitrobenzotrifluoride to be 75:25. This material was used directly in the next step.

1. temperaturewas heated
2. temperatureat reflux under N2 for 16 h
3. temperaturethe mixture was heated
4. temperatureat reflux for another 14 h
5. filtrationthe solid was filtered
6. washwashed with EtOAc
7. washThe combined filtrate was washed with aq. NaHCO3
8. dry with materialdried over Na2SO4
9. filtrationfiltered
10. concentrationconcentrated on rotovap
11. customfurther dried under vacuum