Реакция #42975

Уравнение реакции

4-(4-Chloro-phenyl)-4-hydroxy-3,3-dimethyl-piperidine-1-carboxylic acid tert-butyl ester

trifluoroacetic acid

→

4-(4-Chloro-phenyl)-3,3-dimethyl-piperidin-4-ol

Растворители

methylene chloride

Условия реакции

Обработка

1. 1
   Другоеover 1.25 hours
2. 2
   КонцентрированиеThe mixture was concentrated under reduced pressure
3. 3
   workup.DISSOLUTIONthe residue dissolved in ethyl acetate (1.2 L)
4. 4
   Промывкаwashed with aqueous sodium hydroxide (1 N, 150 mL)
5. 5
   ЭкстракцияThe aqueous layer was extracted with additional ethyl acetate (200 mL)
6. 6
   Промывкаthe combined extracts were washed with brine
7. 7
   Сушкаdried over sodium sulfate
8. 8
   Фильтрацияfiltered
9. 9
   Концентрированиеconcentrated
10. 10
    ДругоеThe resulting solid residue was triturated with ether

Методика

To a cooled (0° C.) solution of 4-(4-Chloro-phenyl)-4-hydroxy-3,3-dimethyl-piperidine-1-carboxylic acid tert-butyl ester (10.42 g, 30.7 mmol) in methylene chloride (300 mL) was slowly added trifluoroacetic acid (60 mL) over 1.25 hours. The resulting yellow solution was stirred at 0° C. for an additional 1.5 hours. The mixture was concentrated under reduced pressure and the residue dissolved in ethyl acetate (1.2 L), and washed with aqueous sodium hydroxide (1 N, 150 mL). The aqueous layer was extracted with additional ethyl acetate (200 mL) and the combined extracts were washed with brine, dried over sodium sulfate, filtered and concentrated. The resulting solid residue was triturated with ether to afford 4-(4-Chloro-phenyl)-3,3-dimethyl-piperidin-4-ol as an off-white solid.

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