Citric Acid → (S)-4-(3-Hydroxy-2-methyl-propyl)-1-((S)-1-phenyl-ethyl)-pyrrolidin-2-one

HRID 458026Notes

Reaction equation

HRID 458026 reaction equation
C[O:2][C:3](=O)[CH:4]([CH3:20])[CH2:5][C@H:6]1[CH2:10][C:9](=[O:11])[N:8]([C@H:12]([C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=2)[CH3:13])[CH2:7]1.[BH4-].[Na+].C(O)(=O)CC(CC(O)=O)(C(O)=O)O.O>CCO>[OH:2][CH2:3][CH:4]([CH3:20])[CH2:5][C@@H:6]1[CH2:7][N:8]([C@H:12]([C:14]2[CH:15]=[CH:16][CH:17]=[CH:18][CH:19]=2)[CH3:13])[C:9](=[O:11])[CH2:10]1

Participants

6

Reactant 4

HCID 311Citric AcidHCID 962WaterHCID 4311764Sodium borohydrideHCID 590940382-Methyl-3-[(S)-5-oxo-1-((S)-1-phenyl-ethyl)-pyrrolidin-3-yl]-propionic Acid Methyl Ester

Product 1

HCID 59093973(S)-4-(3-Hydroxy-2-methyl-propyl)-1-((S)-1-phenyl-ethyl)-pyrrolidin-2-oneYield 59%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Conditions

Temperature
0 °C

Procedure

To the ester 93 (4.82 g, 0.017 mol) in EtOH (100 mL) was added NaBH4 (3.7 g, 0.10 mol) and the mixture heated to reflux for 2.5 hours. The solution was cooled to 0° C. and 1 M citric acid carefully added followed by water. The solution was concentrated to half volume added and extracted with ether. The combined organic extracts were dried (MgSO4) and concentrated. Flash chromatography (1:1 hexane/acetone) of the residue gave the product as an oil (2.6 g, 59%). MS m/z 262 (M+H, 100%).

Workup

  1. temperaturethe mixture heated
  2. temperatureto reflux for 2.5 hours
  3. concentrationThe solution was concentrated to half volume
  4. additionadded
  5. extractionextracted with ether
  6. dry with materialThe combined organic extracts were dried (MgSO4)
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-de5ca674164a484b9cbad86585bbcd12
Source dataset
uspto-grants-2007_03
Patent number
US07189747B2

Reaction notes

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