Potassium Carbonate → (3R,4S)-3-(1-phenyl-ethylamino)-piperidine-1,4-dicarboxylic acid 1-tert-butyl ester 4-ethyl ester

HRID 497465Notes

Reaction equation

HRID 497465 reaction equation
[CH2:1]([O:3][C:4]([C@@H:6]1[CH2:11][CH2:10][N:9]([C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])[CH2:8][C@@H:7]1[NH:19][C@@H:20]([C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1)[CH3:21])=[O:5])[CH3:2].C(=O)([O-])[O-].[K+].[K+]>C(O)C>[CH2:1]([O:3][C:4]([C@H:6]1[CH2:11][CH2:10][N:9]([C:12]([O:14][C:15]([CH3:16])([CH3:17])[CH3:18])=[O:13])[CH2:8][C@@H:7]1[NH:19][CH:20]([C:22]1[CH:23]=[CH:24][CH:25]=[CH:26][CH:27]=1)[CH3:21])=[O:5])[CH3:2]

Participants

4

Procedure

In a dry flask (3R,4R)-3-[(R)-1-phenyl-ethylamino]-piperidine-1,4-dicarboxylic acid 1-tert-butyl ester 4-ethyl ester (31.32 g, 83.0 mmol) was dissolved in ethanol (400 mL). Potassium carbonate (68.72 g) was added and the mixture was refluxed for 6 hours. The reaction mixture was cooled, filtered through a bed of celite, and concentrated in vacuo to give a crude oil. Purification by flash column chromatography (20-50% ethyl acetate/hexanes) provided a colorless oil (4.59 g, 15%). Unepimerized ester was also isolated (23.49 g, 75%).

Workup

  1. temperaturethe mixture was refluxed for 6 hours
  2. temperatureThe reaction mixture was cooled
  3. filtrationfiltered through a bed of celite
  4. concentrationconcentrated in vacuo
  5. customto give a crude oil
  6. customPurification by flash column chromatography (20-50% ethyl acetate/hexanes)

Sources & evidence

ORD record
ord-2b5b542d9bc64276b527f0839bd4b7b9
Source dataset
uspto-grants-2005_09
Patent number
US06949546B2

Reaction notes

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