(3S)-3-Benzyloxycarbonylamino-1-chloro-4-phenyl-2-butanone → Benzyl ((2S,3S)-4-chloro-3-hydroxy-1-phenylbutan-2-yl)carbamate

HRID 54066Notes

Reaction equation

HRID 54066 reaction equation
[BH4-].[Na+].[CH2:3]([O:10][C:11]([NH:13][C@H:14]([C:22]([CH2:24][Cl:25])=[O:23])[CH2:15][C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1)=[O:12])[C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][CH:5]=1.CO.C(Cl)(Cl)Cl>O1CCCC1>[CH2:3]([O:10][C:11]([NH:13][C@@H:14]([CH2:15][C:16]1[CH:17]=[CH:18][CH:19]=[CH:20][CH:21]=1)[C@H:22]([OH:23])[CH2:24][Cl:25])=[O:12])[C:4]1[CH:5]=[CH:6][CH:7]=[CH:8][CH:9]=1

Participants

5

Reactant 3

HCID 99625(3S)-3-Benzyloxycarbonylamino-1-chloro-4-phenyl-2-butanoneHCID 4311764Sodium borohydrideHCID 21584188Chloroform methanol

Product 1

HCID 10860587Benzyl ((2S,3S)-4-chloro-3-hydroxy-1-phenylbutan-2-yl)carbamateYield 54.4%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

3.5 g of sodium borohydride were added to an ice-cooled stirred solution of 21 g of [N-(benzyloxycarbonyl)-L-phenylalanyl]methyl chloride in 500 ml of aqueous tetrahydrofuran. Stirring was continued for 0.5 hour and the solvent was removed by evaporation. The residue was partitioned between dichloromethane and water and then carefully acidified with concentrated hydrochloric acid. After working-up the organic phase gave a white solid which ran as two spots; Rf 0.4 and 0.5 (5% methanol/chloroform). The solids were extracted with boiling hexane until all of the higher running component had been extracted. The combined n-hexane extracts were evaporated and the residue was re-extracted with boiling n-hexane to remove a small amount (0.5 g) of the lower running component. In this manner there were obtained 11.5 g of 3(S)-(benzyloxyformamido)-1-chloro-4-phenyl-2(S)-butanol of melting point 151°-153° C. (from ethyl acetate/n-hexane).

Workup

  1. temperaturecooled
  2. customthe solvent was removed by evaporation
  3. customThe residue was partitioned between dichloromethane and water
  4. customgave a white solid which
  5. extractionThe solids were extracted with boiling hexane until all of the
  6. extractionhad been extracted
  7. customThe combined n-hexane extracts were evaporated
  8. extractionthe residue was re-extracted with boiling n-hexane
  9. customto remove a small amount (0.5 g) of the

Sources & evidence

ORD record
ord-e51dcc607b8f4406800810cdfcbffee5
Source dataset
uspto-grants-1997_04
Patent number
US05620987

Reaction notes

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