反应详情

4-Chloro-2,6-difluorobenzoic acid (500 mg, 2.6 mmol) was added to a solution of diphenylphosphoryl azide (737 mg, 3 mmol) in t-butanol (8 ml) followed by triethylamine (477 ml, 6 mmol) and the mixture heated at reflux for 2 hours. The reaction mixture was allowed to cool and the solvent removed by evaporation. The residue was dissolved in ethyl acetate, washed with water, dried (MgSO4) and purified by column chromatography eluting with increasingly polar mixtures of methylene chloride, hexane and methanol (/1/1/0 to 95/0/5) to give N-t-butoxycarbonyl-4-chloro-2,6-difluoroaniline (170 mg, 25%).

1. temperaturethe mixture heated
2. temperatureat reflux for 2 hours
3. temperatureto cool
4. customthe solvent removed by evaporation
5. dissolutionThe residue was dissolved in ethyl acetate
6. washwashed with water
7. dry with materialdried (MgSO4)
8. custompurified by column chromatography
9. washeluting
10. temperaturewith increasingly polar mixtures of methylene chloride, hexane and methanol (/1/1/0 to 95/0/5)