Dicyclohexylcarbodiimide → N,S-Diacetyl-DL-cysteinyl-L-proline tert-butyl ester

HRID 1252817Notes

Reaction equation

HRID 1252817 reaction equation
[C:1]([O:5][C:6](=[O:12])[C@@H:7]1[CH2:11][CH2:10][CH2:9][NH:8]1)([CH3:4])([CH3:3])[CH3:2].OC1C2N=NNC=2C=CC=1.C1(N=C=NC2CCCCC2)CCCCC1.[C:38]([NH:41][CH:42]([C:48](O)=[O:49])[CH2:43][S:44][C:45](=[O:47])[CH3:46])(=[O:40])[CH3:39]>C(Cl)Cl>[C:1]([O:5][C:6](=[O:12])[C@@H:7]1[CH2:11][CH2:10][CH2:9][N:8]1[C:48](=[O:49])[CH:42]([CH2:43][S:44][C:45](=[O:47])[CH3:46])[NH:41][C:38](=[O:40])[CH3:39])([CH3:4])([CH3:2])[CH3:3]

Participants

6

Reactant 4

HCID 10868DicyclohexylcarbodiimideHCID 4321391HCID 4321391, compoundHCID 6453108L-Proline 1,1-dimethylethyl esterHCID 178418300HCID 178418300, compound

Product 1

HCID 14181603N,S-Diacetyl-DL-cysteinyl-L-proline tert-butyl ester

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of L-proline tert-butyl ester (0.85 g) and hydroxybenzotriazole (0.67 g) in methylene chloride (10 ml) chilled in an ice bath, dicyclohexylcarbodiimide (1.03 g) and N,S-diacetyl-D,L-cysteine (1.7 g) are added in that order. After fifteen minutes, the ice bath is removed and the mixture is stirred at room temperature overnight. The precipitate is filtered off and the filtrate is washed with 10% potassium bisulfate, water, saturated sodium bicarbonate and water. The organic phase is dried and concentrated to dryness in vacuo to give N,S-diacetyl-D,L-cysteinyl-L-proline tert-butyl ester as an oil. Rf =0.25 (silica gel, ethylacetate).

Workup

  1. waitAfter fifteen minutes
  2. customthe ice bath is removed
  3. filtrationThe precipitate is filtered off
  4. washthe filtrate is washed with 10% potassium bisulfate, water, saturated sodium bicarbonate and water
  5. customThe organic phase is dried
  6. concentrationconcentrated to dryness in vacuo

Sources & evidence

ORD record
ord-840f8d3f2bde4858945814d19b0780f4
Source dataset
uspto-grants-1988_05
Patent number
US04745124

Reaction notes

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