Borane → (S)-2-(p-toluenesulfonylamino)-1,4-butanediol

HRID 1646040Notes

Reaction equation

HRID 1646040 reaction equation
[C:1]1([CH3:19])[CH:6]=[CH:5][C:4]([S:7]([NH:10][C@H:11]([C:16](O)=[O:17])[CH2:12][C:13](O)=[O:14])(=[O:9])=[O:8])=[CH:3][CH:2]=1.B>O1CCCC1.CO>[C:1]1([CH3:19])[CH:2]=[CH:3][C:4]([S:7]([NH:10][C@@H:11]([CH2:12][CH2:13][OH:14])[CH2:16][OH:17])(=[O:9])=[O:8])=[CH:5][CH:6]=1

Participants

5

Reactant 2

HCID 6331BoraneHCID 107597N-tosyl-L-aspartic acid

Product 1

HCID 10934189(S)-2-(p-toluenesulfonylamino)-1,4-butanediol

Reagents, catalysts & solvents 2

HCID 887MethanolSolvent2×HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
-5 °C

Procedure

N-(p-Toluenesulfonyl)-L-aspartic acid, 1, (110 g) was dissolved in tetrahydrofuran (300 mL) and the solution cooled to -5° C. under a nitrogen atmosphere. A 1.0 M solution of borane in tetrahydrofuran was added dropwise over 1 hour at 0 to -5° C. and the resulting solution stirred at 20° to 25° C. overnight. The solution was recooled to 0° C. and methanol (250 mL) was added dropwise over 30 minutes (caution! gas evolution). The solution was concentrated under vacuum to an oil which was redissolved in methanol (1 L) and the solution heated at reflux 1 hour. This solution was concentrated under vacuum to give a solid which was redissolved in methanol (1 L) and this solution heated at reflux for 2 hours. Finally the solution was concentrated to a solid which was dried under vacuum at 50° C. to give (S)-2-(p-toluenesulfonylamino)-1,4-butanediol, 2, as an off-white solid (97 g, 98%) which was used directly in the next step without further purification. A portion was recrystallized from isopropyl alcohol and hexanes: mp 90°-92° C.

Workup

  1. customwas recooled to 0° C.
  2. concentrationThe solution was concentrated under vacuum to an oil which
  3. dissolutionwas redissolved in methanol (1 L)
  4. temperaturethe solution heated
  5. temperatureat reflux 1 hour
  6. concentrationThis solution was concentrated under vacuum
  7. customto give a solid which
  8. temperaturethis solution heated
  9. temperatureat reflux for 2 hours
  10. concentrationFinally the solution was concentrated to a solid which
  11. customwas dried under vacuum at 50° C.

Sources & evidence

ORD record
ord-a02ad4c19eff4a98a408893adf5cdb34
Source dataset
uspto-grants-1993_01
Patent number
US05177217

Reaction notes

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