Potassium Carbonate → (3aRS,7aRS)-2-benzyl-7,7-dimethyl-2,3,3a, 4,7,7a-hexahydro-1H-4-isoindolone

HRID 55432Notes

Reaction equation

HRID 55432 reaction equation
[CH3:1][C:2]1([CH3:9])[CH:7]=[CH:6][C:5](=[O:8])[CH:4]=[CH:3]1.C(O[CH2:15][N:16]([CH2:22][C:23]1[CH:28]=[CH:27][CH:26]=[CH:25][CH:24]=1)[CH2:17][Si](C)(C)C)CCC.C(=O)([O-])[O-].[K+].[K+]>ClCCl.FC(F)(F)C(O)=O>[CH2:22]([N:16]1[CH2:17][CH:6]2[CH:7]([C:2]([CH3:9])([CH3:1])[CH:3]=[CH:4][C:5]2=[O:8])[CH2:15]1)[C:23]1[CH:28]=[CH:27][CH:26]=[CH:25][CH:24]=1

Participants

6

Reactant 3

HCID 11430Potassium CarbonateHCID 5563332,5-Cyclohexadien-1-one, 4,4-dimethyl-HCID 11097910N-Benzyl-1-butoxy-N-[(trimethylsilyl)methyl]methanamine

Product 1

HCID 67714301(3aRS,7aRS)-2-benzyl-7,7-dimethyl-2,3,3a, 4,7,7a-hexahydro-1H-4-isoindolone

Reagents, catalysts & solvents 2

HCID 6422Trifluoroacetic acidCatalystHCID 6344DichloromethaneSolvent

Procedure

To a solution of 15.96 g of 4,4-dimethyl-2,5-cyclohexadienone and 46 cm3 of N-butoxymethyl-N-trimethylsilylmethylbenzylamine in 200 cm3 of dichloromethane are added, at a temperature of 10° C., 8 drops of trifluoroacetic acid. The reaction mixture is brought to reflux for 2 hours and potassium carbonate is then added and the solution is filtered through a sinter funnel and concentrated to dryness under reduced pressure (2.7 kPa). The residue is chromatographed on a column of silica gel (particle size 0.04-0.06 mm, diameter 8.5 cm, height 30 cm), eluting under a pressure of 0.5 bar of nitrogen with a mixture of cyclohexane and ethyl acetate (80/20 by volume) and collecting 100 cm3 fractions. Fractions 38 to 56 are combined and concentrated to dryness under reduced pressure (2.7 kPa). 14.7 g of (3aRS,7aRS)-2-benzyl-7,7-dimethyl-2,3,3a, 4,7,7a-hexahydro-1H-4-isoindolone are obtained in the form of a yellow oil.

Workup

  1. temperatureto reflux for 2 hours
  2. filtrationthe solution is filtered through a sinter funnel
  3. concentrationconcentrated to dryness under reduced pressure (2.7 kPa)
  4. customThe residue is chromatographed on a column of silica gel (particle size 0.04-0.06 mm, diameter 8.5 cm, height 30 cm)
  5. washeluting under a pressure of 0.5 bar of nitrogen with a mixture of cyclohexane and ethyl acetate (80/20 by volume)
  6. customcollecting 100 cm3 fractions
  7. concentrationconcentrated to dryness under reduced pressure (2.7 kPa)

Sources & evidence

ORD record
ord-cfe8050af6d84949b4e537a9e4cc4871
Source dataset
uspto-grants-1997_04
Patent number
US05624950

Reaction notes

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