N-tert-Butoxycarbonyl-(2R,4S)-4-fluoroproline benzyl ester → (4S)-1-tert-Butoxycarbonyl-4-fluoro-L-proline

HRID 1244202Notes

Reaction equation

HRID 1244202 reaction equation
C([O:8][C:9](=[O:23])[C@H:10]1[CH2:14][C@H:13]([F:15])[CH2:12][N:11]1[C:16]([O:18][C:19]([CH3:22])([CH3:21])[CH3:20])=[O:17])C1C=CC=CC=1>[Pd].CO>[C:19]([O:18][C:16]([N:11]1[CH2:12][C@@H:13]([F:15])[CH2:14][C@H:10]1[C:9]([OH:23])=[O:8])=[O:17])([CH3:22])([CH3:20])[CH3:21]

Participants

4

Reactant 1

HCID 69621870N-tert-Butoxycarbonyl-(2R,4S)-4-fluoroproline benzyl ester

Product 1

HCID 2756017(4S)-1-tert-Butoxycarbonyl-4-fluoro-L-prolineYield 87.4%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalyst2×HCID 887MethanolSolvent

Procedure

Methanol (95 mL) was carefully added to a mixture of 11 (2.8 g, 8.7 mmol) and palladium on carbon (10% w/w, 1.0 g, 0.94 mmol Pd) under Ar(g). A balloon filled with H2(g) was affixed to the reaction flask, and the mixture was stirred overnight. After 24 h, unreacted starting material remained, so an additional 0.95 g (0.89 mmol Pd) of Pd/C were added and a fresh balloon filled with H2(g) was placed on the flask. After stirring overnight, TLC indicated reaction had gone to completion, and the mixture was filtered through Celite. The filtrate was concentrated to a white solid by rotary evaporation under reduced pressure and dried under vacuum, affording 12 (1.8 g, 7.6 mmol, 87%), which was used without further purification.

Workup

  1. additionA balloon filled with H2(g)
  2. waitAfter 24 h
  3. additiona fresh balloon filled with H2(g)
  4. stirringAfter stirring overnight
  5. customreaction
  6. filtrationthe mixture was filtered through Celite
  7. concentrationThe filtrate was concentrated to a white solid by rotary evaporation under reduced pressure
  8. customdried under vacuum

Sources & evidence

ORD record
ord-ed80efbdbb084cd7a2a12a21bfa5e318
Source dataset
uspto-grants-2006_10
Patent number
US07122521B2

Reaction notes

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