Pyrrolidine → diethyl 3,4-dihydro-4-oxo-7-hydroxy-8-propyl-2H-1-benzopyran-2,2-dipropanoate

HRID 2371610Notes

Reaction equation

HRID 2371610 reaction equation
[O:1]=[C:2]([CH2:10][CH2:11][C:12]([O:14][CH2:15][CH3:16])=[O:13])[CH2:3][CH2:4][C:5]([O:7][CH2:8][CH3:9])=[O:6].[CH3:17][CH2:18][CH2:19][C:20]1[C:25](O)=[C:24]([C:27]([CH3:29])=[O:28])[CH:23]=[CH:22][C:21]=1[OH:30].N1CCCC1>C1(C)C=CC=CC=1>[O:28]=[C:27]1[C:24]2[CH:23]=[CH:22][C:21]([OH:30])=[C:20]([CH2:19][CH2:18][CH3:17])[C:25]=2[O:1][C:2]([CH2:3][CH2:4][C:5]([O:7][CH2:8][CH3:9])=[O:6])([CH2:10][CH2:11][C:12]([O:14][CH2:15][CH3:16])=[O:13])[CH2:29]1

Participants

5

Reactant 3

HCID 31268PyrrolidineHCID 80592Diethyl 4-oxoheptanedioateHCID 27751982',4'-Dihydroxy-3'-propylacetophenone

Product 1

HCID 19756625diethyl 3,4-dihydro-4-oxo-7-hydroxy-8-propyl-2H-1-benzopyran-2,2-dipropanoate

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A stirred solution of 12.3 g (53.5 mmol) of diethyl 4-oxopimelate, 10.4 g (53.5 mmol) of 2,4-dihydroxy-3-propylacetophenone, and 3.8 g (55 mmol) of pyrrolidine in 62 ml of toluene was refluxed under a water separator. After 4 hours, the mixture was allowed to cool. The solvent was removed under reduced pressure and the resultant oil was chromatographed on silica gel using ethyl acetate-hexane as eluent. The titled diester (4.98 g) was found to be homogeneous by thin-layer chromatography (20% by volume ethyl acetate/hexane on silica gel plates) and was used in subsequent reactions without further purification.

Workup

  1. temperatureto cool
  2. customThe solvent was removed under reduced pressure
  3. customthe resultant oil was chromatographed on silica gel
  4. customwas used in subsequent reactions without further purification

Sources & evidence

ORD record
ord-2210308361e84916900ed85c27a213f1
Source dataset
uspto-grants-1992_03
Patent number
US05093353

Reaction notes

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