Water → 4,7-dimethyl-1H-indene

HRID 1613914Notes

Reaction equation

HRID 1613914 reaction equation
[Na].[CH3:2][C:3](=O)[CH2:4][CH2:5][C:6](=O)[CH3:7].[CH:10]1[CH2:14][CH:13]=[CH:12][CH:11]=1.O>CO.C(OCC)C>[CH3:7][C:6]1[CH:5]=[CH:4][C:3]([CH3:2])=[C:10]2[C:11]=1[CH:12]=[CH:13][CH2:14]2

Participants

7

Reactant 4

HCID 962WaterHCID 7612CyclopentadieneHCID 80352,5-HexanedioneHCID 5360545Sodium

Product 1

HCID 814584,7-dimethyl-1H-indene

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 3283Diethyl EtherSolvent

Procedure

23 g (1.0 mol) of sodium were dissolved in 250 ml of absolute methanol. A mixture of 45.6 g (0.40 mol) of 2,5-hexanedione and 39.7 g (0.60 mol) of cyclopentadiene was added dropwise at 0° C. in the course of 1-2 hours. After stirring at room temperature for 1 hour, 50 ml of H2O were added to the dark brown solution. The organic phase was diluted with about 1 l of diethyl ether. The aqueous phase was separated off. The organic phase was dried over sodium sulfate and evaporated. The oil which remained was chromatographed on silica gel 60. 44.2 g (76%) of the indene 1 could be eluted with hexane/methylene chloride (10:1), and is obtained as a colorless to pale yellow oil after the mobile phase has been stripped off under an oil pump vacuum. For the NMR data, see Table 1.

Workup

  1. additionwas added dropwise at 0° C. in the course of 1-2 hours
  2. customThe aqueous phase was separated off
  3. dry with materialThe organic phase was dried over sodium sulfate
  4. customevaporated
  5. customThe oil which remained was chromatographed on silica gel 60
  6. wash44.2 g (76%) of the indene 1 could be eluted with hexane/methylene chloride (10:1)
  7. customis obtained as a colorless to pale yellow oil after the mobile phase

Sources & evidence

ORD record
ord-3b5a9f839dfc4cc9a107a7fb9098cd59
Source dataset
uspto-grants-1993_03
Patent number
US05194619

Reaction notes

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