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

HRID 722856

Reaction equation

HRID 722856 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-a63a3d10edc845d5b5c6df5b80326d5c
Source dataset
uspto-grants-2006_11
Patent number
US07138542B2

Linked notes

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