Dicyclohexylcarbodiimide → 2,2-dimethoxyethyl N-benzyloxycarbonyl-L-valinate

HRID 844516Notes

Reaction equation

HRID 844516 reaction equation
[CH2:1]([O:8][C:9]([NH:11][C@H:12]([C:16]([OH:18])=[O:17])[CH:13]([CH3:15])[CH3:14])=[O:10])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[CH3:19][O:20][CH:21]([O:24][CH3:25])[CH2:22]O.C1CCC(N=C=NC2CCCCC2)CC1>CN(C1C=CN=CC=1)C.ClCCl>[CH2:1]([O:8][C:9]([NH:11][C@H:12]([C:16]([O:18][CH2:22][CH:21]([O:24][CH3:25])[O:20][CH3:19])=[O:17])[CH:13]([CH3:15])[CH3:14])=[O:10])[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

6

Reactant 3

HCID 10868DicyclohexylcarbodiimideHCID 5423812,2-DimethoxyethanolHCID 726987N-Carbobenzoxy-L-valine

Product 1

HCID 701630052,2-dimethoxyethyl N-benzyloxycarbonyl-L-valinateYield 109%

Reagents, catalysts & solvents 2

HCID 142844-(Dimethylamino)pyridineCatalystHCID 6344DichloromethaneSolvent

Procedure

A 100 mL, round bottom flask equipped with a magnetic stirrer and a nitrogen inlet is added N-benzyloxycarbonyl-L-valine (3.6 g), dichloromethane (25 mL), and 2,2-dimethoxyethanol (1.85 g) and the mixture is cooled using an ice bath (0-5° C.). DMAP (0.089 g) is added to the reaction mixture followed by the addition of DCC (3.6 g) over a period of 2 minutes. The suspended solid is filtered, the filter cake is washed with 3×10 mL of heptanes, and the filtrate is concentrated. The crude product is purified by silica gel chromatography (4:1, heptanes/ethyl acetate eluent) to provide 5.3 g of 2,2-dimethoxyethyl N-benzyloxycarbonyl-L-valinate.

Workup

  1. customA 100 mL, round bottom flask equipped with a magnetic stirrer and a nitrogen inlet
  2. temperaturethe mixture is cooled
  3. custom(0-5° C.)
  4. filtrationThe suspended solid is filtered
  5. washthe filter cake is washed with 3×10 mL of heptanes
  6. concentrationthe filtrate is concentrated
  7. customThe crude product is purified by silica gel chromatography (4:1, heptanes/ethyl acetate eluent)

Sources & evidence

ORD record
ord-7746abf5b8b24dd1899edce5dbc15361
Source dataset
uspto-grants-2002_04
Patent number
US06380388B1

Reaction notes

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