反应详情

Tert-butyl 4-hydroxypiperidine-1-carboxylate (2.22 g, 10.0 mmol), 4-hydroxybenzotrifluoride (1.21 g, 7.45 mmol), tri-n-butylphosphine (2.26 g, 11.2 mmol) and 1,1′-(azodicarbonyl)dipiperidine (2.82 g, 11.2 mmol) were dissolved in benzene (20 ml), and the mixture was stirred at room temperature for 2 days. To which water was added, and the mixture was extracted with ethyl acetate. The extract was dried over magnesium sulfate and thereafter filtered, and the filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography (n-hexane/ethyl acetate=5/1) ro afford tert-butyl 4-(4-trifluoromethylphenoxy)piperidine-1-carboxylate (1.13 g, yield 44%) as a colorless oil.

1. extractionthe mixture was extracted with ethyl acetate
2. dry with materialThe extract was dried over magnesium sulfate
3. filtrationfiltered
4. concentrationthe filtrate was concentrated under reduced pressure
5. customThe residue was purified by silica gel column chromatography (n-hexane/ethyl acetate=5/1) ro