Carbon Dioxide → dimethyl 5-(3,4-dichlorophenyl)-2,3-dihydro-1H-pyrrolizine-6,7-dicarboxylate

HRID 569790Notes

Reaction equation

HRID 569790 reaction equation
[Cl:1][C:2]1[CH:3]=[C:4]([CH:15]=[CH:16][C:17]=1[Cl:18])[C:5]([N:7]1[CH2:14][CH2:13][CH2:12][C@H:8]1C(O)=O)=O.C(=O)=O.[C:22]([C:28]([O:30][CH3:31])=[O:29])#[C:23][C:24]([O:26][CH3:27])=[O:25]>C(OC(=O)C)(=O)C>[Cl:1][C:2]1[CH:3]=[C:4]([C:5]2[N:7]3[C:8](=[C:22]([C:28]([O:30][CH3:31])=[O:29])[C:23]=2[C:24]([O:26][CH3:27])=[O:25])[CH2:12][CH2:13][CH2:14]3)[CH:15]=[CH:16][C:17]=1[Cl:18]

Participants

5

Reactant 3

HCID 280Carbon Dioxide2×HCID 12980Dimethyl acetylenedicarboxylateHCID 822734N-(3,4-dichlorobenzoyl)proline

Product 1

HCID 320363dimethyl 5-(3,4-dichlorophenyl)-2,3-dihydro-1H-pyrrolizine-6,7-dicarboxylateYield 91%

Reagents, catalysts & solvents 1

HCID 7918Acetic AnhydrideSolvent

Procedure

A solution of N-(3,4-dichlorobenzoyl)proline (28.813 g 0.1 mol) in acetic anhydride (100 mL) and dimethyl acetylenedicarboxylate (50 mL) was stirred in a flask equipped with a reflux condenser and a gas bubbler to monitor CO2 evolution during the reaction. The mixture was heated to 120° C. over a 15-min period, during which time CO2 evolution occurred at an increasingly rapid rate; the temperature was maintained for 1 h after the rate of gas evolution had substantially decreased. The reaction mixture was concentrated in vacuo and the residue, which solidified on cooling, as twice crystallized from hot methanol (500 mL) to yield 33.35 g (91%) of dimethyl 2,3-dihydro-5-(3,4-dichlorophenyl)-1H-pyrrolizine-6,7-dicarboxylate as analytically pure fine white needles.

Workup

  1. customequipped with a reflux condenser
  2. customduring the reaction
  3. temperaturethe temperature was maintained for 1 h after the rate of gas evolution
  4. concentrationThe reaction mixture was concentrated in vacuo
  5. temperatureon cooling
  6. customas twice crystallized from hot methanol (500 mL)

Sources & evidence

ORD record
ord-fe87e7a0b0b646d5a31dee5672e68d5e
Source dataset
uspto-grants-1988_03
Patent number
US04734423

Reaction notes

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