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

HRID 2083713Notes

Reaction equation

HRID 2083713 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-methyoxycarbonyl-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-ce8ea721555743e5aad0e496929d8b33
Source dataset
uspto-grants-1978_04
Patent number
US04086338

Reaction notes

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