1,8-Diazabicyclo(5.4.0)undec-7-ene → 1-tert-Butyl 3-ethyl 2,5-dihydro-1H-pyrrole-1,3-dicarboxylate

HRID 341771Notes

Reaction equation

HRID 341771 reaction equation
[CH2:1]([O:3][C:4]([CH:6]1[CH:10](OC(=O)C2C=CC=CC=2)[CH2:9][N:8]([C:20]([O:22][C:23]([CH3:26])([CH3:25])[CH3:24])=[O:21])[CH2:7]1)=[O:5])[CH3:2].C1CCN2C(=NCCC2)CC1>C1(C)C=CC=CC=1>[CH2:1]([O:3][C:4]([C:6]1[CH2:7][N:8]([C:20]([O:22][C:23]([CH3:24])([CH3:26])[CH3:25])=[O:21])[CH2:9][CH:10]=1)=[O:5])[CH3:2]

Participants

4

Reactant 2

HCID 811841,8-Diazabicyclo(5.4.0)undec-7-eneHCID 53749205HCID 53749205, compound

Product 1

HCID 538881261-tert-Butyl 3-ethyl 2,5-dihydro-1H-pyrrole-1,3-dicarboxylateYield 86%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

To a solution of the crude 4-benzoyloxy-pyrrolidine-1,3-dicarboxylic acid 1-tert.-butylester 3-ethylester from the benzoylation described above in 75 ml dry toluene was added 4.11 g (27 mmol) DBU. The dark, heterogeneous mixture was stirred at room temperature for 16 h. After this time no starting material was detectable by TLC and GC analysis. The mixture was filtered through a short column of silica (elution with petrolether/ethyl acetate 1:1) and evaporated. Bulb-to-bulb distillation of the residual slightly yellow oil gave 4.16 g (86%) 2,5-dihydro-pyrrole-1,3-dicarboxylic acid 1-tert.-butylester 3-ethyl ester as a colorless oil b.p. 110° C./0.2 mbar, which slowly solidified to a waxy mass on standing in the freezer.

Workup

  1. filtrationThe mixture was filtered through a short column of silica (elution with petrolether/ethyl acetate 1:1)
  2. customevaporated
  3. distillationBulb-to-bulb distillation of the residual slightly yellow oil

Sources & evidence

ORD record
ord-92fbe127e8f041a8a6390fd95a84ee08
Source dataset
uspto-grants-1999_01
Patent number
US05856309

Reaction notes

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