Benzyl chloroformate → (S)-2,5-Dihydro-pyrrole-1,2-dicarboxylic acid 1-benzyl ester

HRID 1052117Notes

Reaction equation

HRID 1052117 reaction equation
[NH:1]1[CH2:5][CH:4]=[CH:3][C@H:2]1[C:6]([OH:8])=[O:7].[OH-].[Na+].[CH2:11]([O:18][C:19](Cl)=[O:20])[C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1>C1COCC1>[CH2:11]([O:18][C:19]([N:1]1[CH2:5][CH:4]=[CH:3][C@H:2]1[C:6]([OH:8])=[O:7])=[O:20])[C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1

Participants

5

Reactant 3

HCID 10387Benzyl chloroformateHCID 14798Sodium HydroxideHCID 942843,4-Dehydro-L-proline

Product 1

HCID 10422063(S)-2,5-Dihydro-pyrrole-1,2-dicarboxylic acid 1-benzyl ester

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of (S)-2,5-dihydro-1H-pyrrole-2-carboxylic acid (15 g, 133 mmol) and sodium hydroxide (10.6 g, 265 mmol) in THF (150 mL) cooled at 0° C. was added benzylchloroformate (32.0 mL, 166 mmol). The mixture was allowed to reach RT overnight. The reaction mixture was concentrated, water was added and the aqueous layer was extracted with Et2O (2×200 mL), acidified (6N HCl) and extracted with AcOEt (2×200 mL). The combined organic extracts were dried (Na2SO4), filtered and concentrated. The crude residue was used in the next step without purification. MS (UPLC/MS): 248 [M+H]+; tR (HPLC conditions b): 1.66 min.

Workup

  1. concentrationThe reaction mixture was concentrated
  2. additionwater was added
  3. extractionthe aqueous layer was extracted with Et2O (2×200 mL)
  4. extractionextracted with AcOEt (2×200 mL)
  5. dry with materialThe combined organic extracts were dried (Na2SO4)
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customThe crude residue was used in the next step without purification
  9. custom1.66 min.

Sources & evidence

ORD record
ord-417e85d1ee254dadadc1834e3d0f1b92
Source dataset
uspto-grants-2016_07
Patent number
US09388199B2

Reaction notes

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