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

HRID 65711Notes

Reaction equation

HRID 65711 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-6ebc9b2741d24305936fcade81575b37
Source dataset
uspto-grants-1978_12
Patent number
US04128653

Reaction notes

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