Triethylamine → (S)-N-CBZ-valinol

HRID 326536Notes

Reaction equation

HRID 326536 reaction equation
Cl[C:2]([O:4][CH2:5][C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1)=[O:3].[NH2:12][C@H:13]([CH2:17][OH:18])[CH:14]([CH3:16])[CH3:15].C(N(CC)CC)C>C(Cl)(Cl)Cl>[CH2:5]([O:4][C:2]([NH:12][C@H:13]([CH2:17][OH:18])[CH:14]([CH3:16])[CH3:15])=[O:3])[C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 10387Benzyl chloroformateHCID 640993L-Valinol

Product 1

HCID 10900657(S)-N-CBZ-valinolYield 79.5%

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent

Conditions

Temperature
0 °C

Procedure

Benzyl chloroformate (91.0 g, 95% purity) was added dropwise over a period of 1 h to a precooled (0° C.) solution of L-valinol (50.0 g) and triethylamine (60.0 g) in chloroform (1500 ml). The reaction mixture was stirred for 1 h at 0° C. and then allowed to warm to,room temperature over 2 h. After the reaction mixture was evaporated, ethyl acetate (1500 ml) was added to the residue and the organic solution was washed (1N NaOH, brine), dried (MgSO4), and evaporated. The residue was purified by flash chromatography, using a stepwise gradient elution of ether:hexane (1:5) followed by ether, to give the alcohol (91.4 g) as a white waxy solid; TLC, Rf =0.23, hexane:ethanol (50:50).

Workup

  1. temperatureto warm to,room temperature over 2 h
  2. customAfter the reaction mixture was evaporated
  3. additionethyl acetate (1500 ml) was added to the residue
  4. washthe organic solution was washed (1N NaOH, brine)
  5. dry with materialdried (MgSO4)
  6. customevaporated
  7. customThe residue was purified by flash chromatography
  8. washa stepwise gradient elution of ether:hexane (1:5)

Sources & evidence

ORD record
ord-3f551c17853f43e9992170149f9e5f33
Source dataset
uspto-grants-1993_12
Patent number
US05270301

Reaction notes

Loading…