Diethyl Ether → 2-[2-(4-Fluorophenyl)acetyl]-4-hydroxypyrazolidine-1-carboxylic acid benzyl ester

HRID 2052877Notes

Reaction equation

HRID 2052877 reaction equation
[CH2:1]([O:8][C:9]([N:11]1[CH2:15][C:14](=[O:16])[CH2:13][N:12]1[C:17](=[O:26])[CH2:18][C:19]1[CH:24]=[CH:23][C:22]([F:25])=[CH:21][CH:20]=1)=[O:10])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.CCOCC>C1COCC1>[CH2:1]([O:8][C:9]([N:11]1[CH2:15][CH:14]([OH:16])[CH2:13][N:12]1[C:17](=[O:26])[CH2:18][C:19]1[CH:24]=[CH:23][C:22]([F:25])=[CH:21][CH:20]=1)=[O:10])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

4

Reactant 2

HCID 3283Diethyl EtherHCID 129701552-[2-(4-Fluorophenyl)acetyl]-4-oxo-pyrazolidine-1-carboxylic acid benzyl ester

Product 1

HCID 207247442-[2-(4-Fluorophenyl)acetyl]-4-hydroxypyrazolidine-1-carboxylic acid benzyl esterYield 73%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
-78 °C

Procedure

2-[2-(4-Fluorophenyl)acetyl]-4-oxo-pyrazolidine-1-carboxylic acid benzyl ester, 11, (1.0 g, 2.81 mmol) is dissolved in THF (30 mL) and the solution cooled to −78° C. A 5.0 M solution of borane-dimethyl sulfide complex in ether (1.2 mL, 5.61 mmol) is added dropwise. After 1 hour at −78° C., the reaction is quenched by slow addition of NH4Cl (sat. aq.) (10 mL). The cooling bath is then removed, and the mixture allowed to warm to room temperature with vigorous stirring. The THF is removed in vacuo and the residue diluted with water (50 mL). The mixture is extracted with ethyl acetate (2×100 mL), dried, filtered and concentrated in vacuo to give a yellow oil which is purified over silica (1:1 to 1:2 hexane/ethyl acetate to 100% ethyl acetate) to afford 731 mg (73% yield) as a clear, viscous oil.

Workup

  1. customthe reaction is quenched by slow addition of NH4Cl (sat. aq.) (10 mL)
  2. customThe cooling bath is then removed
  3. temperatureto warm to room temperature with vigorous stirring
  4. customThe THF is removed in vacuo
  5. additionthe residue diluted with water (50 mL)
  6. extractionThe mixture is extracted with ethyl acetate (2×100 mL)
  7. customdried
  8. filtrationfiltered
  9. concentrationconcentrated in vacuo
  10. customto give a yellow oil which
  11. customis purified over silica (1:1 to 1:2 hexane/ethyl acetate to 100% ethyl acetate)
  12. customto afford 731 mg (73% yield) as a clear, viscous oil

Sources & evidence

ORD record
ord-4177a5c0f9be4d7a893a7dfedbb9f45d
Source dataset
uspto-grants-2008_02
Patent number
US07326714B2

Reaction notes

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