Dicyclohexylcarbodiimide → 1-(2-ethoxycarbonylpropanoyl)-L-proline tert.-butyl ester

HRID 972325Notes

Reaction equation

HRID 972325 reaction equation
[CH2:1]([O:3][C:4](=[O:10])[CH:5]([CH3:9])[C:6]([O-:8])=O)[CH3:2].[C:11]([O:15][C:16](=[O:22])[C@@H:17]1[CH2:21][CH2:20][CH2:19][NH:18]1)([CH3:14])([CH3:13])[CH3:12].C1(N=C=NC2CCCCC2)CCCCC1>ClCCl>[C:11]([O:15][C:16](=[O:22])[C@@H:17]1[CH2:21][CH2:20][CH2:19][N:18]1[C:6](=[O:8])[CH:5]([C:4]([O:3][CH2:1][CH3:2])=[O:10])[CH3:9])([CH3:14])([CH3:12])[CH3:13]

Participants

5

Reactant 3

HCID 10868DicyclohexylcarbodiimideHCID 6453108L-Proline 1,1-dimethylethyl esterHCID 22667308Monoethylmethylmalonate

Product 1

HCID 706103371-(2-ethoxycarbonylpropanoyl)-L-proline tert.-butyl ester

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

Monoethylmethylmalonate [prepared according to the procedure of Organic Syntheses, 37, 34 (1957)](2.92 g.) and L-proline tert.-butyl ester (3.42 g.) are dissolved in dichloromethane (80 ml.). The solution is chilled with stirring in an ice bath. Dicyclohexylcarbodiimide (4.12 g.) is added and the mixture is stirred 15 minutes in the ice bath and 16 hours at room temperature. The precipitate is filtered off and the filtrate concentrated to dryness in vacuo. The residue is dissolved in ethyl acetate and washed with 5% aqueous potassium bisulfate, water, saturated sodium bicarbonate and water. The organic phase is dried over magnesium sulfate and concentrated to dryness in vacuo to obtain 1-(2-ethoxycarbonylpropanoyl)-L-proline tert.-butyl ester, yield 5.9 g.

Workup

  1. temperatureThe solution is chilled
  2. filtrationThe precipitate is filtered off
  3. concentrationthe filtrate concentrated to dryness in vacuo
  4. dissolutionThe residue is dissolved in ethyl acetate
  5. washwashed with 5% aqueous potassium bisulfate, water, saturated sodium bicarbonate and water
  6. dry with materialThe organic phase is dried over magnesium sulfate
  7. concentrationconcentrated to dryness in vacuo

Sources & evidence

ORD record
ord-91d94a3912c24140a6cd7eb8fe537b38
Source dataset
uspto-grants-1977_10
Patent number
US04052511

Reaction notes

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