반응 #42975

반응 방정식

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

용매

methylene chloride

반응 조건

후처리

1. 1
   기타over 1.25 hours
2. 2
   농축The mixture was concentrated under reduced pressure
3. 3
   workup.DISSOLUTIONthe residue dissolved in ethyl acetate (1.2 L)
4. 4
   세척washed with aqueous sodium hydroxide (1 N, 150 mL)
5. 5
   추출The aqueous layer was extracted with additional ethyl acetate (200 mL)
6. 6
   세척the combined extracts were washed with brine
7. 7
   건조dried over sodium sulfate
8. 8
   여과filtered
9. 9
   농축concentrated
10. 10
    기타The resulting solid residue was triturated with ether

실험 절차

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.

출처