反应详情

2,6-Dimethyl-4-trifluoromethylpyridine-3-carboxylic acid hydrochloride (23.17 g, 90.6 mmol) was suspended in tert-butanol (175 mL). Diphenylphosphonic azide (35.25 g, 128.1 mmol) and triethylamine (31.36 g, 309.9 mmol) were added to the suspension, followed by refluxing for 3 hours. The reaction mixture was allowed to stand for cooling. Subsequently, water (100 mL) was added to the mixture, followed by extraction with chloroform. The obtained organic layer was dried over sodium sulfate anhydrate, followed by concentration under reduced pressure. The obtained residue was purified through silica gel column chromatography (eluent: n-hexane: acetone=10:1), to thereby yield 3-tert-butoxycarbonylamino-2,6-dimethyl-4-trifluoromethylpyridine as a pale yellow oil (18.01 g, 68%).

1. temperatureby refluxing for 3 hours
2. temperaturefor cooling
3. extractionfollowed by extraction with chloroform
4. dry with materialThe obtained organic layer was dried over sodium sulfate anhydrate
5. concentrationfollowed by concentration under reduced pressure
6. customThe obtained residue was purified through silica gel column chromatography (eluent: n-hexane: acetone=10:1)