Diisobutylaluminum hydride → (R)-tert-Butyl (1-(4-bromophenyl)-3-oxopropan-2-yl)carbamate

HRID 1469676Notes

Reaction equation

HRID 1469676 reaction equation
C[O:2][C:3](=O)[C@H:4]([NH:13][C:14]([O:16][C:17]([CH3:20])([CH3:19])[CH3:18])=[O:15])[CH2:5][C:6]1[CH:11]=[CH:10][C:9]([Br:12])=[CH:8][CH:7]=1.CC(C[AlH]CC(C)C)C>C(Cl)Cl>[C:17]([O:16][C:14](=[O:15])[NH:13][C@H:4]([CH2:5][C:6]1[CH:7]=[CH:8][C:9]([Br:12])=[CH:10][CH:11]=1)[CH:3]=[O:2])([CH3:20])([CH3:18])[CH3:19]

Participants

4

Reactant 2

HCID 14487Diisobutylaluminum hydrideHCID 15735974Boc-4-bromo-D-phenylalanine methyl ester

Product 1

HCID 59608321(R)-tert-Butyl (1-(4-bromophenyl)-3-oxopropan-2-yl)carbamate

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

Next, to a solution of (R)-3-(4-bromo-phenyl)-2-tert-butoxycarbonylamino-propionic acid methyl ester (1.0 g, 2.79 mmol) in DCM (20 mL) is added DIBAL-H (4.85 mL, 1.0M in DCM) slowly by using syringe pump at −78° C. After the addition is complete the reaction is quenched by adding EtOAc and the mixture is warmed to room temperature. Then a saturated sodium potassium tartaric acid is added and the mixture is and stirred at room temperature for 1 hour. The organic phase is separated and the aqueous layer is extracted with EtOAc. The combined organic layers were washed with brine, dried over MgSO4, filtered and concentrated to give [(R)-1-(4-bromo-benzyl)-2-oxo-ethyl]-carbamic acid tert-butyl ester which is used directly in the next reaction.

Workup

  1. customat −78° C
  2. additionAfter the addition
  3. customis quenched
  4. additionby adding EtOAc
  5. additionThen a saturated sodium potassium tartaric acid is added
  6. customThe organic phase is separated
  7. extractionthe aqueous layer is extracted with EtOAc
  8. washThe combined organic layers were washed with brine
  9. dry with materialdried over MgSO4
  10. filtrationfiltered
  11. concentrationconcentrated

Sources & evidence

ORD record
ord-105bd5ea75d64b499805229d327ed666
Source dataset
uspto-grants-2015_04
Patent number
US09006249B2

Reaction notes

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