Diethyl Malonate → 1,3-Dihydroindene-2,2-dicarboxylic acid

HRID 728250Notes

Reaction equation

HRID 728250 reaction equation
[Na].[C:2]([O:10]CC)(=[O:9])[CH2:3][C:4]([O:6]CC)=[O:5].Br[CH2:14][C:15]1[C:16]([CH2:21]Br)=[CH:17][CH:18]=[CH:19][CH:20]=1>C(O)C.C(OCC)C>[CH2:21]1[C:16]2[C:15](=[CH:20][CH:19]=[CH:18][CH:17]=2)[CH2:14][C:3]1([C:4]([OH:6])=[O:5])[C:2]([OH:10])=[O:9]

Participants

6

Reactant 3

HCID 7761Diethyl MalonateHCID 66665o-Bis(bromomethyl)benzeneHCID 5360545Sodium

Product 1

HCID 2519571,3-Dihydroindene-2,2-dicarboxylic acid

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 3283Diethyl EtherSolvent2×

Procedure

Sodium (3.7 g) was dissolved in 80 ml of ethyl alcohol, followed by the addition of 150 ml of diethyl ether. Diethyl malonate (12.5 ml) was added followed by 20 g of α,α'-dibromo-o-xylene in 150 ml of diethyl ether with overhead stirring. The reaction was heated to reflux for 5 hours. The reaction was cooled, filtered, and the solvent was removed under vacuum. The residue was treated with a potassium hydroxide solution (20 g in 125 ml of water) and heated to reflux for 15 hours. The reaction was then cooled and rinsed with 200 ml of diethyl ether. The aqueous phase was acidified with 30% hydrochloric acid. The precipitate was collected and dried under vacuum over Drieruite for 5 hours to yield 8.86 g of indan-2,2-dicarboxylic acid.

Workup

  1. temperatureThe reaction was heated
  2. temperatureto reflux for 5 hours
  3. temperatureThe reaction was cooled
  4. filtrationfiltered
  5. customthe solvent was removed under vacuum
  6. additionThe residue was treated with a potassium hydroxide solution (20 g in 125 ml of water)
  7. temperatureheated
  8. temperatureto reflux for 15 hours
  9. temperatureThe reaction was then cooled
  10. washrinsed with 200 ml of diethyl ether
  11. customThe precipitate was collected
  12. customdried under vacuum over Drieruite for 5 hours

Sources & evidence

ORD record
ord-1e03a6a2a9ca49e0b48e43c94918861a
Source dataset
uspto-grants-1991_09
Patent number
US05047534

Reaction notes

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