Dicyclohexylcarbodiimide → 1-(4-methoxycarbonyl-2-methylbutanoyl)-L-proline tert.-butyl ester

HRID 65717Notes

Reaction equation

HRID 65717 reaction equation
[CH3:1][O:2][C:3]([CH2:5][CH2:6][CH:7]([CH3:11])[C:8]([OH:10])=O)=[O:4].[C:12]([O:16][C:17](=[O:23])[C@@H:18]1[CH2:22][CH2:21][CH2:20][NH:19]1)([CH3:15])([CH3:14])[CH3:13].C1(N=C=NC2CCCCC2)CCCCC1>ClCCl>[C:12]([O:16][C:17](=[O:23])[C@@H:18]1[CH2:22][CH2:21][CH2:20][N:19]1[C:8](=[O:10])[CH:7]([CH3:11])[CH2:6][CH2:5][C:3]([O:2][CH3:1])=[O:4])([CH3:15])([CH3:13])[CH3:14]

Participants

5

Reactant 3

HCID 10868DicyclohexylcarbodiimideHCID 6453108L-Proline 1,1-dimethylethyl esterHCID 131928974-Carbomethoxy-2-methylbutanoic acid

Product 1

HCID 706097971-(4-methoxycarbonyl-2-methylbutanoyl)-L-proline tert.-butyl ester

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

4-Methoxycarbonyl-2-methylbutanoic acid (3.1 g.) and L-proline tert.-butyl ester (3.78 g.) are dissolved in dichloromethane (40 ml.). The solution is chilled with stirring in an ice bath and dicyclohexylcarbodiimide (4.12 g.) is added. After stirring 15 minutes in the ice bath and 18 hours at room temperature, the precipitate is filtered off and the filtrate is concentrated to dryness in vacuo. The residue is chromatographed on a column of silica gel with chloroform to obtain 1-(4-methoxycarbonyl-2-methylbutanoyl)-L-proline tert.-butyl ester, yield 3.5 g.

Workup

  1. temperatureThe solution is chilled
  2. filtrationthe precipitate is filtered off
  3. concentrationthe filtrate is concentrated to dryness in vacuo
  4. customThe residue is chromatographed on a column of silica gel with chloroform

Sources & evidence

ORD record
ord-f60916127bbf444b9b9c00029bd28bb6
Source dataset
uspto-grants-1978_12
Patent number
US04128653

Reaction notes

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